Citation
Design of Secondary Control Surfaces on Unmanned Aircraft Systems to Achieve Low Glide Slope Ratios

Material Information

Title:
Design of Secondary Control Surfaces on Unmanned Aircraft Systems to Achieve Low Glide Slope Ratios
Creator:
Balmori, Abraham
Place of Publication:
[Gainesville, Fla.]
Florida
Publisher:
University of Florida
Publication Date:
Language:
english
Physical Description:
1 online resource (69 p.)

Thesis/Dissertation Information

Degree:
Master's ( M.S.)
Degree Grantor:
University of Florida
Degree Disciplines:
Aerospace Engineering
Mechanical and Aerospace Engineering
Committee Chair:
IFJU,PETER G
Committee Co-Chair:
LIND JR,RICHARD C
Graduation Date:
8/9/2014

Subjects

Subjects / Keywords:
Aircraft ( jstor )
Aircraft wings ( jstor )
Altitude ( jstor )
Automatic pilots ( jstor )
Control surfaces ( jstor )
Glide paths ( jstor )
Remotely piloted vehicles ( jstor )
Spoilers ( jstor )
Vehicular flight ( jstor )
Wing flaps ( jstor )
Mechanical and Aerospace Engineering -- Dissertations, Academic -- UF
aircraft -- control -- flap -- glide -- hybrid -- landing -- nova -- slope -- spoiler -- surfaces -- uas -- uav
City of Gainesville ( local )
Genre:
bibliography ( marcgt )
theses ( marcgt )
government publication (state, provincial, terriorial, dependent) ( marcgt )
born-digital ( sobekcm )
Electronic Thesis or Dissertation
Aerospace Engineering thesis, M.S.

Notes

Abstract:
The mission environment for the Nova 2.1 unmanned aerial system (UAS) is typically constrictive and challenging to operate in. One of the most crucial factors to consider when looking at an area to be surveyed using an unmanned aerial vehicle (UAV) is the location of operation. The location must provide the aircraft safe terrain to land on to avoid not only damaging the sensor package but also protecting the aircraft itself. The large amount of space needed to land the aircraft is seldom found in the areas typically surveyed, such as brush plains, forests, or rocky terrain areas, which may cover the landscape for miles. To minimize the damage to the airframe as well as provide more options to land, a device that can be deployed to aid the aircraft was needed. The requirements for such a device include a significant amount of drag and lift generated as well as not incurring any pitching moment when activated. A number of ideas were first tested on a 1:3 scale model aircraft resembling the Nova 2.1. From the initial trial study, three secondary control devices were built and tested on the full scale Nova 2.1 aircraft. The most promising secondary control device tested was the hybrid flap/spoiler, where the device when activated created lift and drag using one surface, reducing the landing distance by nearly 400 meters. Through repeated testing it was determined that a Nova 2.1 UAS system can achieve a glide slope ratio of 3.3 using the hybrid flap/spoiler system (HFS). An area a third of the length previously needed to land the Nova 2.1 is now all that is required to safely land the aircraft and its payload. ( en )
General Note:
In the series University of Florida Digital Collections.
General Note:
Includes vita.
Bibliography:
Includes bibliographical references.
Source of Description:
Description based on online resource; title from PDF title page.
Source of Description:
This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Thesis:
Thesis (M.S.)--University of Florida, 2014.
Local:
Adviser: IFJU,PETER G.
Local:
Co-adviser: LIND JR,RICHARD C.
Electronic Access:
RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2015-02-28
Statement of Responsibility:
by Abraham Balmori.

Record Information

Source Institution:
UFRGP
Rights Management:
Copyright Balmori, Abraham. Permission granted to the University of Florida to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Embargo Date:
2/28/2015
Classification:
LD1780 2014 ( lcc )

Downloads

This item has the following downloads:


Full Text

PAGE 1

1 DESIGN OF SECONDARY CONTROL SURFACES ON UNMANNED AIRCRAFT SYSTEMS TO ACHIEVE LOW GLIDE SLOPE RATIOS By ABRAHAM BALMORI A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2014

PAGE 2

2 © 2014 Abraham Balmori

PAGE 3

3 To Mom, Dad, Katerina, Natalie, and Elizabeth

PAGE 4

4 ACKNOWLEDGEMENTS I would like to thank my m other and f ather for providing me with all the opportunities to succeed. Your undying support was the greatest reason I have made it this far. Your guidance and wisdom have helped me time and time again to stay on track and I am forever grateful. It would be impossible to look back on these past three years and ignore all the people who have come together to contribute so much to the research group. Through both good and bad times we've managed to accomplish so much with the support of each other, carrying on the legacy of our novel unmanned aerial vehicle program. Dr. Ifju, thank you for giving me the opportunity to pursue a graduate degree and work with such exciting and emerging technology. Your experience and perspective have taught me a great deal. Dr. Percival, thank you for being ever enthusiastic about our program and keeping the team motivated to continue to achieve. Matt, your talent at managing the logistics, dealing with unforeseen problems , and lack o f complaint has kept us all afloat and this program moving in the right direction. Lastly, I thank my colleagues, Tyler Ward and Travis Whitley, for the countless hours spent on the Nova platform. Tyler, thank you for your hard work in providing our progr am the payloads it needs to keep moving forward. Your assistance with this thesis, despite it dividing your time, helped me greatly. Travis, thank you for your dedication to not only ensure the operation of the autopilot and the assistance with gathering d ata used in this thesis, but also your efforts on missions. I wish you both luck with your doctoral studies.

PAGE 5

5 TABLE OF CONTENTS Page ACKNOWLEDGMENTS........................................................................ ........... ................4 LIST OF TABLES......................................................................................... .......... ..........7 LIST OF FIGURES.................... ............................................................. ........... ...............8 LIST OF ABBREVIATIONS...................................................................... ........... ...........10 AB STRACT........................................................................................ .............. ...............12 CHAPTER 1 INTRODUC TION............................................................................ .......... ...........14 Unmanned Aircraft Systems Research Group (UASRG) Background .......... ......14 Motivatio n.... ........................................................................................ ........... .....16 Design Considerations.. ................................................................... ........... .. .......16 Summary of the Design Goals.................................... .......................... ........... ....19 2 LITERATURE REVIEW .................................................. .................... .......... .......21 Passive Lift Enhancement .................................................................. .......... .......21 Drag Generating Devices ................................................................ .......... ...... .. ...27 3 PRELIMINARY SECONDARY CONTROL SURFACE DESIGN......... ........... .....31 Trial Study ................. ........................................................................... ........... .....31 First Wing: Flaps and Spoilerons ........................................................ ........... ...... 32 Second Wing: Airbrakes and Flaps .............................................. ........... ............. 34 Third Wing: Hybrid Flap/Spoiler ................................................ ........... ................37 Fourth Wing: Fabric Extension................................................. ........... .................39 Interpreting the Results.......................................................... ........... ...................40 4 DETAILED CONTROL SURFACE DESIGN............................ ........... ................. 42 In depth Design Study.............................................................. .......... ................. 42 First Wing: Airbrakes and Flaps....................... ................. ........... ........................ 42 Second Wing: Flaps and Spoilerons ................................ ........... ......................... 44 Third Wi ng: Hybrid Flap/Spoiler ....................................... ........... ......................... 45 Results ............................................................................. ........... ......................... 47 5 SUMMARY AND CONCLUSIONS ................................... ........... ........................ .50

PAGE 6

6 Summary ..................................................................... ........... ............................. .50 Conclusion .................................................................................. ........... .............. 51 Recommendations ........................ ............................................. .......... ............ . ... 52 APPENDIX : EXAMPLE NOVA 2.1 TELEMETRY DATA ............... .......... ...................... 56 LIST OF REFERENCES ......... ...................................................... ........... ....................... 66 BIOGRAPHICAL SKETCH............................................................ ........... ...................... 69

PAGE 7

7 LIST OF TABLES Table Page 2 1 Comparison of common TE flaps..............................................................25 2 2 Comparison of common LE flaps.................................. ............................25

PAGE 8

8 LIST OF FIGURES Figure Page 1 1 GCS and crew on boat off a mission site near Cedar Key........................15 2 1 Changes in C L ction................................22 2 2 The effect of slat deflection on C L 2 3 Four common TE flap types......................................................................24 2 4 Four common LE flap types......................................................................24 2 5 Tail foam core with ar amid hinge installed, pre layup...............................26 2 6 Spoilers deployed on a wing of an airliner.................. ..............................27 2 7 Ventral side airbrakes deployed during landing........................................28 2 8 Petal airbrakes in use on a Blackburn Buccaneer....................................29 2 9 Airbrakes deployed on rudder of a space shuttle......................................30 3 1 Three scaled wings and the airframe used in trial testing phase..............31 3 2 3 3 Test wing with traditional flaps and spoilerons fully engaged.................. .33 3 4 Schempp Hirth airbrakes extended...........................................................35 3 5 Fully extended Schempp Hirth airbrakes on a test wing...........................36 3 6 The underside of a test wing displaying the flap portion of the HFS........ .37 3 7 The topside of a test wing displaying th e spoiler of the HFS....................38 3 8 Test wing equipped with Icarex extension................................................ 39 4 1 Flaps and airbrakes deployed on full scale Nova 2.1 UAS...................... .43 4 2 Flaps and spoilerons deployed on a full scale Nova 2.1 wing.................. 44 4 3 The topside of the full scale wing, with the HFS deployed....................... .46 4 4 The underside of the full scale wing, with the HFS deployed ....................46

PAGE 9

9 4 5 Landing results with airbrakes and flaps utilized......... ..............................48 4 6 Landing results with HFS utilized.................................. ............................49 5 1 Visual representation of the three modifiable parameters on the HFS.....5 2 5 2 Deflections when moving t he location of the pivot point on the HFS........5 3 5 3 Variations to the HFS chord length...........................................................5 4 5 4 Variations to the wedge angle of the HFS.......... .......................................54

PAGE 10

10 LIST OF ABBREVIATIONS AR Aspect Ratio C L Coefficient of Lift , Maximum Coefficient of Lift D Drag ft Feet GCP Ground Control Point GCS Ground Control Station GPS Global Positioning System GSR Glide Slope Ratio H Altitude at the beginning of the descent HFS Hybrid Flap/Spoiler in Inch L Lift LE Leading Edge m Meters m/s Meters per Second R Horizontal distanced traveled on descent rad Radians RC Remote Controlled Radius of Earth (near Equator) S Wing Area s Seconds

PAGE 11

11 TE Trailing Edge UAS Unmanned Aerial System UASRG Unmanned Aerial System Research Group UAV Unmanned Aerial Vehicle UF University of Florida Stall Speed W Weig ht Angle of Attack Difference of first and second longitude value Difference of first and second latitude value Interior Spherical Angle First latitude value Second latitude value Air Density ° Degrees

PAGE 12

12 Abstract of Thesis Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science DESIGN OF SECONDARY CONTROL SURFACES ON UNMANNED AIRCRAFT SYSTEMS TO ACHIEVE LOW GLIDE SLOPE RA TIOS By Abraham Balmori August 2014 Chair: Peter Ifju Major: Aerospace Engineering The mission environment for the Nova 2.1 unmanned aerial system (UAS) is typically constrictive and challenging to operate in. One of the most crucial factors to cons ider when looking at an area to be surveyed using an unmanned aerial vehicle (UAV) is the location of operation. The location must provide the aircraft safe terrain to land on to avoid not only damaging the sensor package but also protecting the aircraft itself. The large amount of space needed to land the aircraft is seldom found in the areas typically surveyed, such as brush plains, forests, or rocky terrain areas, which may cover the landscape for miles. To minimize the damage to the airframe as well as provide more options to land, a device that can be deployed to aid the aircraft was needed. The requirements for such a device include a significant amount of drag and lift generated as well as not incurring any pitching moment when activated. A number of ideas were first tested on a 1: 3 scale model aircraft resembling the Nova 2.1. From the initial trial study, three secondary control devices were built and test ed on the full scale Nova 2.1 aircraft. The most promising secondary control device tested was the hybrid flap/spoiler, where the device when activated created lift and drag using one surface , reducing the landing distance by nearly 400 meters. Through repeated testing it was

PAGE 13

13 determined that a Nova 2.1 UAS system can achieve a glide slope ratio of 3 .3 using the hybrid flap/spoiler system (HFS). An area a third of the length previously needed to land the Nova 2.1 is now all that is required to safely land the aircraft and its payload.

PAGE 14

14 CHAPTER 1 INTRODUCTION Unmanned Aircraft Systems Research Group (UASRG) Background For over fifteen years, a multidisciplinary research group has strived to develop unmanned aircraft systems (UAS) that are affordable, versatile, simple, and accurate for the purposes of monitoring wildlife habitats and conducting nat ural resource assessments. The University of Florida (UF) departments of Mechanical and Aerospace Engineering, School of Forest Resources and Conservation's Geomatics Program, and Institute of Food and Agricultural Sciences at the University of Florida hav e collaborated to develop a UAS as a platform that can be operated in remote areas of interest to gather direct georeferenced imagery . 1 The imagery is organized into mosaicked orthophotos at a faster rate than traditional methods that require presurvey ed ground control points (GCPs). 2 Regions that were inaccessible to surveying due to the inability to setup GCPs are now open to surveying from the air with the UAS. Aquatic areas, such as islands or swamps, are also accessible to the team. An example of the ground control station (GCS) on a boat off an island, shown in Figure 1 1, displays the versatility the UF UASRG has to complete missions.

PAGE 15

15 Figure 1 1. GCS and crew n ear a mission site in Cedar Key (Abraham Balmori, Seahorse Key Flight . May 5, 2014. Cedar Key, FL). In comparison to manned aerial surveying from a helicopter or fixed wing aircraft, the UAS is capable of collecting higher resolution images due to the low operating altitudes at which it flies . In addition to better qualit y imagery, utilizing the Nova 2.1 UAS to gather data in dangerous locations, such as river valleys, near power lines, and remote locations, eliminates the risk pilots and biologist run when attempting manned flights. Between 1937 and 2000, 60 biologists ha ve lost their lives during aviation incidents while conducting wildlife research or management. 3 The Nova 2.1 UAS can be used instead to prevent accidental death without sacrificing the quality of data gathered. The group has also focused on creating a sys tem that is highly mobile, has low operational cost with respect to traditional methods, and can be deployed frequently, to meet the budgets and needs of researchers.

PAGE 16

16 Motivation The Nova 2.1 UAS was modeled after aircraft typically classified as gliders . A glider configuration was chosen to maximize efficiency in flight and the amount of collectable data . 1 Gliders feature long wingspans with high aspect ratios (AR) to reduce induced drag 4 which increases the total possible flight time . 5 Many gliders also have no landing gear to reduce weight and further increase flight time. The Nova 2.1's design borrows both of these common glider features to maximize the amount of data that can be gathered per battery charge. The Nova 2.1 was also desi gned to minimized the amount of structural weight, allowing for heavier payloads to be loaded. 1 The Nova 2.1 was also designed to land on either earth or water topographies. To land in such environments, the aircraft does not contain traditional landing ge ar, such as wheels or skis, but rather lands on its belly. The Nova 2.1 in the past usually requires a long landing strip to land within, primarily due to the fact the aircraft performs similarly to a glider. Despite cutting the throttle upon landing the a ircraft continues to travel without slowing down or stalling for a lengthy distance, typically 10 to 12 times the horizontal distance with respect from the initial altitude the plane is at when landing. Design Considerations Unfortunately, all of the fact ors mentioned previously regarding the design of the Nova 2.1 require that a much greater area be needed to land the aircraft. When descending during a landing approach the aircraft loses little momentum and airspeed despite the throttle being cut to 0%, i ncreasing the time /range it takes the aircraft to safely touchdown . 6 A phenomena known as ground effect lengthens the time it takes the aircraft to land. Ground effect occurs when the cushion of air exists between the ground

PAGE 17

17 and the underside of the wings of the Nova 2.1. The effect is magnified by the high AR of the wings of the Nova 2.1. A static pressure pocket builds beneath the wings resulting in the generation of additional lift and a reduction of induced drag. Ground effect also occurs over both land and water. Conversely, a downwards pitching moment increases as the plane closes the distance to the ground which actually assists the aircraft to touchdown. The increase in pitching moment due to ground effect is due to the center of pressure moving forw ard. The static pressure increase on the underside of the wing results in a nearly uniform pressure distribution while the topside pressure remains the same. The change in the center of pressure creates a moment about the aerodynamic center of the wing, ca using a pitching moment to form. Ground effect usually occurs in the final moments before the aircraft contacts the surface. 7 11 Carefully planned locations to serve as landing strips for the Nova 2.1 have to be scouted during missions, ensuring that the re is an adequate landing area to accommodate the glider and potential ground effects. Attempts at landing the Nova 2.1 have often lead to overshooting the desired landing area leading the aircraft to touchdown in less favorable terrain. The aircraft has e xperienced extensive damage due to overshot landings. In addition to the risk of damage, the number of suitable locations to operate from is reduced due to the landing strip constraint. By creating a secondary device that would be used during landing appro aches to combat the se negative effects, the aircraft would be brought down on a shorter landing strip at a steeper descent slope, reducing damage to the aircraft and increasing the number of viable locations to operate the UAS from.

PAGE 18

18 The main goal of the d esign of the secondary control surfaces was to decrease the glide slope ratio when landing the aircraft. The glide slope ratio corresponds to the ratio of lift (denoted as L) to drag (denoted as D) which is equivalent to the distance travelled horizontally (denoted as R ) to the initial altitude at the beginning of the descent (denoted as H ) as shown below in Equation 1 1. 12 = = (1 1) The Nova 2.1 without addition al landing devices, for example, takes around 500 to 600 meters to land when descending from an altitude of 60 meters, assuming minimal head or tail wind affects the aircraft. Due to the nature of the missions the UAS RG is typically tasked with, such a long landing approach limits the areas where the aircraft can be safely put down. One of the primary considerations when designing the secondary control surfaces is to minimize the amount of pitching moment induced when activating the control surfaces. The airc raft in descent should not pitch upwards or require significant amount of throttle so the aircraft does not gain altitude or speed. Also, pitching should be minimized so the autopilot does not need to correct more so than usual when landing. Any pitching m oment added could adversely affect the effectiveness of the devices used as well as a sharp pitching up of the aircraft, which could stall the wing or tail and render any corrective control ineffective. Another design point of the secondary control surfac e was that the device must be retractable in case of a bad approach. Employing a device such as a parachute to assist the aircraft upon landing restricts the amount of control the GCS operators have in correcting the approach. If something were to go awry with the aircraft or its landing

PAGE 19

19 vector, the GCS operators need to be able to manually control the aircraft to abort the landing. Losing control of the aircraft upon landing increases not only the chances for damage to the aircraft but would also create a dangerous situation that could harm nearby personnel. In addition to safety concerns, the aircraft is susceptible to being carried off target and landing in an undesired location, such as on priva te property, water, or in trees. 13 Therefore, one time deplo yable devices, such as traditional parachutes or drogue chutes, were not considered viable options to aid landing the aircraft. The final design point was that the device should not significantly protrude out of the wing and must be capable of resisting w ater intrusion. Any part of the Nova 2.1 that protrudes from the aircraft is susceptible to damage upon landing due to the small amount of ground clearance when belly landing. Also, since the Nova 2.1 was designed to land on water, any part of the device v ulnerable to water damage, such as corrosion or electrical failure, must be protected or moved so that water intrusion is minimized. Summary of the Design Goals The purpose of this thesis was to aid the Nova 2.1 in landing to achieve a GSR of 3. To achiev e this goal, secondary devices were designed to minimize landing distance and stall speed. Another stipulation of the design was to retain controllability during descent when deploying the additional control surfaces. The device (s) should be designed to mi nimize additional weight and mechan ical complexity. The deployment and retraction should be quick in case a landing need s to be cancelled. The device (s) needs to be compatible with the GCS software without requiring additional hardware/software to deploy. Given the environmental conditions the Nova 2.1 operates

PAGE 20

20 in , the additional system (s) should be durable and waterproof. The stipulations ensure that any device(s ) chosen from the study would be ready to use immediately.

PAGE 21

21 CHAPTER 2 LITERATURE REVIEW Passive Lift Enhancement Since the beginning of manned flight there has been a need to maximize flight performance during takeoff and landings. One of the first instances were a device was used to generate additional lift in flight date back to 1910, where the Leblon Monoplane featured an adjus table deflection trailing edge. 14 Since then, several additional methods of improving flight efficiency in certain flight regimes have been developed. One of the most commonly used lift enhancement device is the flap. The flap was first commonly seen in the early 20th century aircraft as part of the main wing, typically located on the trailing edge. They were used to improve takeoff and landing performance as well as aid combat maneuvers such as diving. 15 Flaps are characterized as portions of the wing which can be moved separately . One of the main functions of the flap is to modify the curvature of the airfoil to increase the lift generated by the wing. 16 By utilizing flap devices, the curvature of the airfoil, (called the camber), can be increased in flight, affecting the total lift produced. Drag from the pressure build up at the protruding area of the flap, known as parasit ic drag, also results from the usage of flaps. 17 Another beneficial effect from using flaps is the airfoil experiences an increase in chord line, is angled upward re lative to motion of the airfoil through the airflow when the flaps are engaged. The change in the virtual angle of attack shifts the coefficient of lift (C L L is significantly increased when co mpared t o a wing without flaps. 18 An example the effect of flaps have on changing the basic wing's lift properties is shown in Figure 2 1.

PAGE 22

22 Figure 2 1 . Changes in C L versus 19 Increasing the coefficient of lift of the wing at a level flight orientation decreases the stall speed of the wing (assuming no acceleration and level attitude) , as explained in Equation 2 1. = 2 , (2 1) Lowering the stall speed allows for the aircraft to maintain flight when la nding at a slower speed, reducing the horizontal distance travelled. Some flaps also function by increasing the chord size of the wing. Wings made larger by extendable flaps generate more lift but also increase drag, thereby shortening the flight time. Cer tain flaps (such as Fowler flaps) that move rearward are used to extend the effective wing area at specific parts of the flight, such as takeoff and landing. Leading edge slots and flaps work by

PAGE 23

23 modifying the wings LE curvature. Usually, a portion of the w ing is translated (Figure 2 3) , more lift is generated when the camber of the wing and effective angle of attack is increased. Also, LE flaps (Figure 2 4) allow the fl ow over to stay attached to the wing of the aircraft by increasing the LE radius and minimizing the maximum pressure distribution . 20 Slotted LE flaps allow high energy airflow from the underside of the wing to the topside of the wing, allowing an aircraft to fly at h speeds. 21 Slats have the same effect of slots but are retractable. Figure 2 2 illustrates an example of the effects LE slats have on enhancing lift seen in wind tunnel testing. Figure 2 2 . The effect of slat deflection on C L 22 Figures 2 3 and 2 4 display an example of each flap's geometry and Table 1 1 compares the common classes of flap types in use today.

PAGE 24

24 Figure 2 3 . Four common TE flap types. 23 Figure 2 4 . Three common LE flap types . 20

PAGE 25

25 Table 2 1. Comparison of common TE flaps. 24 29 Flap Name Advantages Disadvantages Plain Simplest design to implement, creates additional lift relative to non flapped wings Not as effective as more advanced types of TE flaps, causes downwards pitching moment Fowler Added momentum to boundary layer on topside of flap which increases effective wing area, generating the more lift than other flap types Most complicated flap to implement in terms of actuation and installation on wing, downwards pitching moment Split Nearly identical lift produced by plain flap but with much more drag generated Slightly more complex physical structure compared to plain flaps, downwards pitching moment Slotted Allows transfer of high pressure air from underside of wing to topside, allowing greater flap deflections to be used without flow separation Slightly more complex to implement compared to plain flaps, downwards pitching moment Table 2 2. Comparison of common LE flaps. 20,21,30,31,32 Flap Name Advantages Disadvantages Plain LE Flap Allows the aircraft to be simple hinge construction Unsafe installation location (prone to damage) LE Kruger Flaps Allows the aircraft to be Lighter weight than plain LE Flap Unsafe installation location (prone to damage) , complex mechanism Slat Allows the aircraft to be More effective than LE flaps, prevents flow separation Unsafe installation location (prone to damage) , complex mechanism

PAGE 26

26 The simplest device to construct and install is the plain flap. Plain flaps are characterized as a portion of wing that deflects downward . Implementing plain flaps would consist of the same procedures used when installing ailerons or control surfaces on the ta il on the Nova 2.1 . All control surfaces on the Nova 2.1 hinge about an aramid strip between the composite skin and foam airfoil, as shown in Figure 2 5. Figure 2 5. Tail foam core with ar amid hinge installed, pre layup (Abraham Balmori, Tail Foam Cor e. October 31, 2013. Gainesville, FL). A plain flap can easily be adapted to the wing of the Nova 2.1 by hinging them in the same manner as ailerons, however, a flap that detaches and moves outward from the wing would require a different hinge technique. Split flaps would require slightly more effort to install than plain flaps since they work by deflecting a plate from the bottom of a portion of the wing near the TE. The Nova 2.1 main wing's airfoil is thin, especially near the TE, so installing a plate or hinging an existing piece of the wing may prove challenging. Bearing in mind the size of the Nova 2.1 wing's, some of these flap mechanisms would be too complex to scale down to a size small enough to install. Fowler flaps, for

PAGE 27

27 example, would require supporting structure inside the thin wings of the Nova 2.1 to allow not only the rotational movement but also translational movement . Devices with parts that function by translating forward from the LE or rearward from the TE would require more servo power and strengthening to use properly. Devices found on the LE of the wing are particularly prone to damage upon landing from debris and therefore were not considered for the Nova 2.1. Drag Generating Devices Lift enhancement is not the only desired effect needed on landing. As mentioned previously, the Nova 2.1 has trouble slowing down when landing. A device commonly used on aircraft to create drag and assist steep landings is the spoiler. 33 The spoiler is a device that is typically embedded in the wing whe n not in use and activated during landing (Figure 2 6) . Figure 2 6. Spoilers deployed on a wing of an airliner. ( Reprinted with permission from Tim Caynes. Wing 5 , June 9, 2008 . Retrieved via Flickr under the Creative Commons Attribution NonCommercia license ) .

PAGE 28

28 The spoiler works by disturbing the air flow over the wing, causing downstream flow separation. By engaging a surface that directly resists the airflow drag is increased thereby slowing the aircraft on descent. Disturbing the flow across the win g also reduces lift . 34 Spoilers can also be used for flig ht path correction when landing. 35 To counteract the negative loss of lift effect , flaps are typically deployed in conjunction with spoi lers during a landing approach. Another mechanism used to crea te drag is the airbrake. Airbrakes are analogous to spoilers where both devices are used to create more drag and slow down the aircraft. They are also distinctively different in that airbrakes are designed not to cause a substantial down force when engaged , unlike spoilers. 36 Airbrakes are located commonly on the dorsal side of the wing or fuselage, the ventral side of the wing or fuselage (Figure 2 7) , near the rearmost tip of the fuselage (Figure 2 8 ), or coupled with primary control surfaces. 37 Figure 2 7. Ventral side airbrakes deployed during landing ( Reprinted with permission from Geoff Collins . de Havil l and Moth Min or . May 16, 2007 . Retrieved via Flickr under the Creative Commons Attribution NonCommercial NoDerivs license ) .

PAGE 29

29 Figure 2 8 . Petal a irbrakes in use on a Blackburn Buccaneer ( Reprinted with permission from Nelson Cunnington. DSCN6333 . April 10, 2012 . Retrieved via Flickr under the Creative Commons Attribution NonCommercial NoDerivs license ) . Mounting an airbrake on the ventral side of the wing or fuselage was immediately ruled out since the Nova 2.1 lands on its belly. Installing petal airbrakes on the Nova 2.1 fuselage was also ruled out as a potential device for testing due to lack of substantial tail boom area to mount to. Couplin g an airbrake plate with a control surface, such as with rudder shown in Figure 2 9 , was also ruled out due to the thin airfoils found on the Nova 2.1 tail's V tail.

PAGE 30

30 Figure 2 9 . Airbrakes deployed on rudder of a space shuttle ( Reprinted with permission from NASA HQ PHOTO. Discovery STS 133 Mission Landing . March 9, 2011 . Retrieved via Flickr under the Creative Commons Attribution NonCommercial license ) .

PAGE 31

31 CHAPTER 3 PRELIMINARY SECONDARY CONTROL SURFACE DESIGN Trial Study A number of concepts and devices were surveyed to potentially apply to the Nova 2.1 wing. Many devices, such as LE flaps, were not considered for testing due to risks involving potential damage on landing or in deployment. Some of the secondary devices for controlling the rate and slope of descent were considered based on their usefulness in glider type aircraft . Other devices were derived from large, manned aircraft and sized down. Each of the devices chosen for the preliminary study were constructed on a 1: 3 scale wings emulating the same process used to produce the Nova 2.1 wings ( Figure 3 1) . Figure 3 1. Three scaled wings and the airfr ame used in trial testing phase (Abraham Balmori, Small Scale Wings. March 25, 2014. Gainesville, FL).

PAGE 32

32 These wings would be flown on a remotely controlled (RC) airframe (shown in Figure 3 2) to gauge their effectiveness in slowing down the aircraft, maintaining altitude at near stalling speeds, negative effects upon deployment, and on potential of increasing the glide slope ratio upon landing. Figure 3 2. Test a ircraft used during trial study (Abraham Balmori, Test Aircraft 1. May 22, 2014. Gainesville, FL). A standard wing without additional control surfaces installed was flown to set the baseline. Feedback from the pilot and visual observations from spectators were used to compare the devices. Test flight days were conducted with no overcast skies to increase visibility during observation. The aircraft was also flown with minimal wind speed to lessen the i mpact of wind aiding or hindering the aircraft during testing. First Wing: Flaps and Spoilerons The first arrangement of secondary control surfaces used in the study were traditional flaps coupled with spoilerons. Spoilerons are a combination of tradition al

PAGE 33

33 spoilers and ailerons, where the ailerons on the wing are engaged to a trim upwards position on both ends of the wing. The effect of spoilerons is to increase drag and dump airspeed on the landing approach while maintaining the ability to roll the aircr aft to correct the trajectory. Spoilerons, unfortunately, reduce the amount of roll correction control the pilot has in comparison to normal ailerons. Flaps were coupled with the spoilerons to not only increase drag but also, more importantly, lower the st all speed of the wing and compensate for the loss of lift generated by the spoilerons. The coupling of the two devices would, theoretically, allow the aircraft to descend at a slower rate . Both spoilerons and flaps were set to fully deploy at the same time . When landing the test aircraft the pilot brought the aircraft at the slowest possible speed without stalling and potentially crashing the aircraft. The deflection of the flaps in the trial was set 30 ° . The spoilerons, when engaged, were set at 20 ° deflec tion upwards (as shown in Figure 3 3) . Figure 3 3 . Test wing with traditional flaps and spoilerons fully e ngaged (Abraham Balmori, Spoilerons and Flaps. June 16, 2014. Gainesville, FL).

PAGE 34

34 During the test flights, the spoilers and flaps were engaged sep arately at an altitude of roughly 100 m to determine their individual effectiveness and observe any potential adverse effects. The devices were engaged when the aircraft was in a steady, level flight, and the throttle setting was fixed so that any changes to the flight path and airspeed would be attributed to the device used solely. The test flights for all the wings in the trial study were conducted on days where the local constant wind speeds did not exceed 5 mph. This was done to reduce any effect the wi nd might have on the response of the aircraft when testing. The spoilers, when engaged, exhibited little to no affect on decreasing the airspeed of the aircraft. Second Wing: Airbrakes and Flaps The second setup on a wing was a combination of airbrakes a nd flaps. The airbrakes used on the wing are typical of airbrakes found on manned gliders. The Schempp Hirth airbrakes are extendable areas that impede flow along the wing but not completely disrupt the flow. Ventilation slots or gaps long the airbrake all ow for some airflow to pass through (Figure 3 4) . Increasing the gap between the airbrake and surface results in l ess lift dumping and more drag. 38 The airbrakes are also sized to resist the airflow over a small portion of the wing, so as not to disrupt th e airflow and cause a sudden total loss of lift.

PAGE 35

35 Figure 3 4 . S chempp Hirth airbrakes extended (Abraham Balmori, Airbrakes. May 25, 2014. Gainesville, FL). The wing devices are designed to function similarly to the previously described wing where the airbrakes are deployed to achieve the desired drag for descent and the flaps are extended to maintain flight at a low airspeed without allowing stall to occur. Two set tings were flown for comparison: a partially extended airbrake and a fully extended airbr ake ( Figure 3 5) .

PAGE 36

36 Figure 3 5 . Fully extended Schempp Hirth airbrakes on a test wing (Abraham Balmori, Airbrake Test Wing. May 7, 2014. Gainesville, FL). The first flight was with the airbrake fully extended, when triggered by the pilot. At a safe altitude, the airbrake was deployed, resulting in a sharp loss of altitude. The loss of altitude was most likely due to flow separation formed by the airbrakes . 38 As the pressure built up at the interface between the wing and the front of the airbrakes lea ding edge flow separation occurred which lead to section stall. The areas away from the location of the airbrakes also beg an to experience stall effects. 39 The amount of flow stopped by the fully extended airbrakes proved too great for a small scale wing t o handle. The second flight featuring the airbrake was conducted so the area exposed when deploying the airbrake was half of that exposed in the first flight. Upon triggering the airbrake in flight, the observer viewed minimal downwards pitching and a noti ceable decrease in airspeed. The pilot confirmed the observation, noting that little additional elevator deflection was needed to maintain the aircraft at a level attitude.

PAGE 37

37 Third Wing: Hybrid Flap/Spoiler The next wing device tested was the novel hybrid flap/spoiler (HFS) , invented by Professor Ifju and myself . Due to the uniqueness of the design, Professor and I have applied for an invention disclosure (#15273) with the University of Florida. The main motivation behind the design of the HFS was t o achieve the desired glide slope upon landing with a single servo driving the device per side, unlike the previously mentioned wings featuring two servos per side. The single servo moves the HFS about a pivot point forward of the servo horn, running throu gh wing. As shown in Figures 3 6 and 3 7 , a servo connected to a horn on the HFS pulls the flap portion towards the leading edge of the wing while the top spoiler portion rotates clockwise, towards the trailing edge of the wing. Figure 3 6 . The underside of a test wing display ing the flap portion of the HFS (Abraham Balmori, HFS 1. May 22, 2014. Gainesville, FL).

PAGE 38

38 Figure 3 7 . The topside of a test wing di splaying the spoiler of the HFS (Abraham Balmori, HFS 2. May 22, 2014. Gainesville, FL). The location of pivot point was selected to balance out the moment of the spoiler drag and the moment created by the additional lift from the flap portion of the HFS to eliminate any pitching moment created when deployed. The ratio of effective flap to spoiler area was 3:2. An additional beneficial quality of the HFS is that it is load balanced. A servo would require less force to actuate the device since the air f l ow catches the HFS and assists in rotating it to the desirable position. The servo need ed to move the HFS would need less torque with respect to other secondary control devices and therefore a weaker, lighter servo can be installed. The test flights with the HFS showed promising results. When engaged, the aircraft did not exhibit any sudden pitch changes but did noticeably decrease flight speed, more so than any other device during the initial study.

PAGE 39

39 Fourth Wing: Fabric Extension The final wing design that was tested during the trial stage was a wing that featured a folding fabric wing extension, dubbed the "bat wing". Inspired from devices with low glide slopes, such as parachutes and wing suits, the bat wing was an extension of the main wing that could be deployed or retracted in flight. The fabric chosen was Icarex . Icarex is a nylon based fabric typically found on kites, because it is lightweight and strong enough not to tear or billow excessively in flight under load. The test wing, shown in Figure 3 8 , did not feature the extending/retracting system to simplify the early study. Figure 3 8 . Test wing equipped with Icarex extension (Abraham Balmori, Icarex Wing. May 22, 2014. Gainesville, FL). The goal of the flight was t w o pronged; to determine if the aircraft was controllable with the Icarex extension and to see if increasing the wing area had any appreciable effect

PAGE 40

40 when slowing down the aircraft when landing. The extension increased the total wing area from 201 in 2 to 273 in 2 , or 35.8%. The aircraft was flyable with the Icarex extension and the extension integrity was mai ntained through multiple flights. The comparison between the bat wing and normal wing showed little difference between two in terms of flight performance . There were no significant differences in the flight performance when landing the tes t aircraft with and without the bat wing. Interpreting the Results The first wing tested was the combination flaps/spoilerons wing. Initially, flaps were engaged at a safe altitude to observe their effective on the flight performance of the aircraft . The aircraft visibly slowed down while maintaining the same altitude with minimal pitching. The pilot reported that little elevator deflection was used to correct for any pitching the flaps may have caused. Spoilerons, conversely, did not seem to create enough drag to produce any noticeable deceleration when deployed singularly. During landing, both devices were deployed resulting in a steeper glide slope than the baseline aircraft. The next device tested was the airbrakes. When the airbrakes were deployed at full deflection the aircraft exhibited a great loss of altitude. As discussed previously, the effect at full deflection proved too much for the smaller wing to handle. The airbrakes installed were originally marketed as airbrakes for use on sailplanes with wingspans of 8 ft or more. After seeing the drastic effect the airbrakes had another flight was conducted with the deflection set to half that of the first flight. When deployed in the air the aircraft decelerated as before but did not pitch down significantly or lose al titude. Upon landing

PAGE 41

41 the pilot reported a fair amount of pitch correction was need to maintain a level landing. The experience from the previously mention flight shows that while the airbrakes did prove useful in decelerating the aircraft, they needed to b e coupled with a lift enhancing device, such as the plain flaps from the first study. Based on the test flight results, it was determined that for the next stage of testing a wing with both flaps and airbrakes installed. The next device tested was the HFS . At a safe altitude, the HFS was engaged and the aircraft did not noticeably pitch up or down. The airspeed was clearly decreased and this was confirmed after several successful landings. Upon landing, the HFS wing exhibited a steeper glide slope than the baseline wing. Due to the positive results in the trial test, the HFS was chosen to be built for the full scale stage. The final device tested was the bat wing. The bat wing, unlike the previous wings, showed little effect on the flight performance of th e aircraft in the air as well as during landing. The poor results from the trial stage coupled with the complexity of installing an extendable/retractable fabric extension on a full scale wing was enough to exclude the bat wing from being tested in the nex t stage.

PAGE 42

42 CHAPTER 4 DETAILED CONTROL SURFACE DESIGN In Depth Design Study The next stage of testing was building full scale wings to test on the Nova 2.1 platform , based on the lessons learned from the small scale study. Two wings were built to test th e three configurations of devices chosen. One wing contained flaps and airbrakes. The same wing was also used to test spoilerons and flaps. A second wing was built to test just the HFS configuration. The Nova 2.1 aircraft was to be equipped with the Proce the same autopilot used in the field to collect data. The autopilot has two role s. Firstly, to ensure the aircraft descends for a landing in a repeatable approach , and secondly, to collect telemetry data from the onboard accelerome ter and magnetometer sensors. The telemetry and GPS data was used to record the aircraft's speed, wind speed, attitude, altitude, and distance traveled . This information was used to determine the response of the autopilot when each device wa s engaged. The GPS data provided an accurate horizontal distance traveled by the aircraft based on the position packets from where the plane beg an its descent to its final resting position. The horizontal distance was used with the initial altitude reading at the beginni ng the landing approach to determine the glide slope ratio. First Wing: Airbrakes and Flaps The first full scale wing tested was a combination of airbrakes and flaps pictured in Figure 4 1.

PAGE 43

43 Figure 4 1. Flaps and airbrakes deployed on a full scale Nova 2 .1 wing (Abraham Balmori, Test Wing 1. May 27, 2014. Gainesville, FL). The flaps were 5 in wide by 20 in long and set to deploy at 30° downwards. The airbrakes, which were synchronized to extend when the flaps were deployed, were set to the maximum deflection possible: 13/16" upward. The full deflection was used since the Nova 2.1's wing span of 9 ft was on par with the manufacturer's suggested wing size. Via the GCS, a flight path was charted to climb from takeoff position to a safe altitude of 150 m where each device could be tested and observed individually. In flight readings of the wind speed indicated stable wind speeds of 3 mph, with little to no gusting. Following a successful engagement of the flaps and airbrakes, the aircraft was to descend to an altitude of 60 m and begin its descent to land. A number of aborted landings were intentionally conducted to gauge whether the aircraft landing with secondary controls enabled could be brought back out of a descent and climb to safe altitude. The pi lot was successfully able to take manual control and abort the landing while the GCS operator disengaged the secondary control devices. After the aborted

PAGE 44

44 landing trials were conducted the GCS operator set parameters in the virtual cockpit , which were trans mitted to the autopilot , to land the aircraft at the slowest possible speed without stalling and /or potentially crashing the aircraft. The Nova 2.1 landed multiple times without incident under these conditions. Second Wing: Flaps and Spoilerons The second combination of secondary control devices used in a full scale test were flaps and spoilerons as shown in Figure 4 2. Figure 4 2. Flaps and spoilerons deploye d on a full scale Nova 2.1 wing (Abraham Balmori, Test Wing 2. June 23, 2014. Gainesville, FL). The wing from the previous test was used so the flap size remained the same. Spoilerons were activated through the Kestrel autopilot system by enabling a trigger that could be switched when deployment was desired. On ce the spoilerons were engaged, the autopilot was automatically triggered to maintain zero bank angle when landing and restricted the ability to course correct by rolling the aircraft. Once again,

PAGE 45

45 both devices were set up to deploy at the same time upon la nding, after safe observations were made of their individual effects to the aircraft in level flight. The test flight was conducted the same day seeing as the previous wing as well as wind conditions remained unchanged . As before, the aircraft was brought to a landing approach that would be aborted. The aircraft had no issues recovering from the landing descent or gaining altitude again. However, when the aircraft was brought to finally land it misaligned the approach with the runway. This caused the aircra ft to crash into a nearby forest. Third Wing: Hybrid Flap/Spoiler The second full scale wing tested was the HFS wing. The same aspect ratio of the small scale HFS (4:1) was maintain ed when the full scale version was constructed. Spring loaded pins on eith er side of the wing allowed for pivoting when a torque was applied by a servo . The ratio of effective flap to spoiler area was 3:2, as with the small scale version (Figures 4 3 and 4 4) . As for the previous attempts, a flight path was charted to climb from takeoff position to a n altitude of 150 m where the HFS was tested and observed. In flight readings of the local wind speed indicated stable speeds of 6 mph, with slight gusting. When the HFS was engaged at 150 m the aircraft did not exhibit any pitching o r significant loss of altitude. The autopilot had to increase the throttle percentage to maintain a constant speed when the Nova 2.1 experienced the drag force produced by the HFS. As before, the aborted landing tests were conducted successfully. The aircraft then descend ed to an altitude of 75 m and begin its final approach to land. Multiple successful landings were performed and recorded.

PAGE 46

46 . Figure 4 3. The topside of the full scale wing, with the HFS deployed (Abraham Balmori, HFS Topside. M ay 30, 2014. Gainesville, FL). Figure 4 4. The underside of the full scale wing, with the HFS deployed (Abraham Balmori, HFS Underside. May 30, 2014. Gainesville, FL).

PAGE 47

47 Results The most successful result from landing the full scale wing with airbra kes and flaps is shown in Figure 4 5. The GSR for all wings was calculated by determining the horizontal distance traveled using the GPS recorded latitudes and longitudes during the descent. These values, using the haversine formula (4 1) below, were conve rted to a distance along a spherical shape ( in this case the Earth). 40 = 2 arcsin 2 2 + 2 2 (4 1) The value from equation 4 1 was then multiplied by the approximate radiu s of the Earth near the equator 40 , shown in Equation 4 2, to provide us with the horizontal leg of the descent slope. = (4 2) The vertical distance traveled, denoted as H in Equation 1 1, was determined from the altitude readings produced by the onboard pitot sensor. The l anding glide slope was set to 2 through the autopilot since previous landings showed that the landing glide slopes were overshot. By setting the GSR to 2 the Nova 2.1 was brought down at a steeper initial angle, which the aircraft was unable to achieve (Fi gure 4 5).

PAGE 48

48 Figure 4 5 . Landing results with airbrakes and flaps utilized. These settings coupled with the deployment of the secondary control devices brought the aircraft down on a GSR of 3.6. The desired airspeed, set at the stall speed of the wing, was over shot during the descent, causing the aircraft to impact the ground at 17 m/s, about 2 m/s faster than unaided landings conducted in the past. The HFS wing fared much better in bringing down the Nova 2.1 to the desired slope, set in the autopilot. Based on the results from the airbrake/flap wing, the autopilot was programme d to land the aircraft at a GSR of 3. The adjustment in GSR was to increase the time the aircraft had to decelerate, therefore contacting the ground with less energy than the first round of flights. As shown in Figure 4 6, the autopilot handled tracking th e desired GSR much better and was ultimately able to achieve a GSR of 3.3. 0 10 20 30 40 50 60 0 2 4 6 8 10 12 Altitude (m), Airspeed (m/s) Relative Time (s) Glide Slope 3.6 Actual Altitude Actual Airspeed Desired Altitude Desired Airspeed

PAGE 49

49 Figure 4 6 . Landing results with HFS utilized. The final configuration tested was the spoilerons/flaps wing. The aircraft was sent to conduct a landing approach after testing each device. During final approach, the aircraft seemed to be aligned with the preprogrammed path chosen to safely land. In the final seconds it was apparent that the aircraft was misaligned with the clearing chosen to serve as a runway. The aircraft overs hot the clearing and continued descending until colliding with trees in a nearby forest. As mentioned previously, the autopilot switches to a specific mode when engaging the spoilerons, where flight path correction is disabled and the autopilot uses the pr imary control surfaces only to maintain level attitude. The mode was determined to be the root cause, driving the aircraft off course. The spoilerons/flaps wing was considered not useful because of the poor performance during the trial flights as well as t he crash during the full scale flights. 0 10 20 30 40 50 60 70 0 5 10 15 Altitude (m), Airspeed (m/s) Relative Time (s) Glide Slope 3.3 Actual Altitude Actual Airspeed Desired Altitude Desired Airspeed

PAGE 50

50 CHAPTER 5 SUMMARY AND CONCLUSIONS Summary The purpose of this thesis was to create a system for aiding the Nova 2.1 aircraft when landing. To achieve the design goals expressed in Chapter 1, a survey of secondary control devices was conducted. Commonly used devices to aid aircraft during landing, such as various flaps, spoilers, and airbrakes, were assessed for their potential use on the Nova 2.1. Advantages and disadvantages were weighed with each device and an ac ceptable set were chosen to be tested on a small scale aircraft. The small scale testing provided a qualitative report on the effectiveness of each device. Fabricating the test wings also provided insight to how each device would best be installed on the N ova 2.1 aircraft, if selected for the next round of tests. Following the conclusion of the trial test, three of the four wing configurations were selected to be built into full scale models and tested on the Nova 2.1. Full scale tests were conducted using the autopilot as a data acquisition device. The autopilot was also commanded to land the aircraft precisely, to generate repeatable, controlled landing approaches. Out of the three wing device configurations tested, two performed favorably while one result ed in a crash. The airbrake/flap combination was able to achieve a GSR of 3.6 while the HFS wing was able to land at a GSR of 3.3. The results showed that employing certain secondary devices to assist landing could reduce the necessary runway length to a t hird of its current size. The HFS device proved to not only be the best choice in reducing the GSR but also relatively simple to implement.

PAGE 51

51 Conclusions Through careful research, a number of supporting devices were surveyed and tested. Conventional as we ll as unconventional devices were tested on both small and full scale platforms. Testing showed the promise of some devices and the shortcomings of others. Ultimately the HFS system proved most effective in decreasing the GSR of the aircraft down to one third of its original value. The HFS also was specifically designed to fulfill all of the other requirements needed to create a truly useful device to aid the Nova 2.1. The uniqueness of the HFS was a result of its tailor made function: to slow down verti cally and horizontally a small UAV. Due to the specific function of the HFS, it is possible that a similar device was not explored as a means to aid manned aircraft. The potential for UAV usage, however, is immense and, with further refinements, the HFS co uld become conventional secondary control device. As the research presented in the thesis show, the number of possible regions to land the Nova 2.1 has been increased significantly. The HFS is ready to be installed onto Nova 2.1 wings and deployed on missi ons abroad.

PAGE 52

52 Recommendations The re is great poten tial for the HFS system . Further refinements can be made by adjusting the three key aspects of the design to achieve optimal effectiveness. The three variables that can be modified to improve the effective ness of the HFS are the location of the pivot along the chord of the HFS, the flap length of the HFS, and the wedge angle of the leading edge of the HFS. Figure 5 1 visualizes the adjustable parameters of the HFS. Figure 5 1. Visual representation of the three modifiable parameters on the HFS. Each of these parameters can be individually tested to determine their contributions to generating more lift, drag, and/ or minimizing pitching moment. An example of the physical effect on moving the pivot is illustrated in Figure 5 2.

PAGE 53

53 Figure 5 2 . Deflections when moving the location of the pivot point on the HFS. By adjusting the pivot point on the HFS the ratio between t he exposed area above the wing, the spoiler portion, and the exposed area below the wing, the flap portion, can be changed. As with most secondary control devices, overall length can be adjusted until the desired effect is reached (Figure 5 3). The HFS c hord length can be varied to determine the best suited length to assist the Nova 2.1 on landing. Sizing the chord length too short could detract from the potential contribution the HFS has on decreasing the GSR. Sizing the chord length too long can weaken the structure of the entire wing, as well as generate flow separation.

PAGE 54

54 Figure 5 3 Variations to the HFS chord length. The wedge angle of the HFS can be adjusted as well (Figure 5 4). The wedge angle directly affects the effective spoiler contribution of the HFS. If the optimal deployment deflection is known, the best wedge angle can be determined to create a perpendicular face to airflow, increasing the amount of drag added. The wedge angle also affects the gap in the wing exposed when the HFS is deploy ed. This gap allows accelerated airflow to pass under the spoiler segment of the HFS, potentially increasing the amount of lift generated by the flap segment. Figure 5 4. Variations to the wedge angle of the HFS.

PAGE 55

55 Utilizing a wind tunnel to create a mode l or trend for the individual contributions of each variable, a constrained optimization technique can be employed to determine the best configuration of all three variables on a Nova 2.1 HFS.

PAGE 56

56 APPENDIX EXAMPLE NOVA 2.1 TELEMETRY DATA The following data represents the telemetry information produced by the autopilot during one successful landing attempt. The data was used to determine information such as the true glide slope ratio achieved with corrections added for wind effects. The GPS onboard the Nova 2 .1 indicated the aircraft's heading, latitude, and longitude. Wind speed (not shown), as indicated by the autopilot, never exceeded 1.44 m/s upon landing for this example data . Desired turn rate and throttle percentage (not shown) were automatically set to 0 when in landing mode. The relative time from the beginning of the landing descent was repor ted in milliseconds. Altitude and airspeed are reported by the autopilot in meters and meters per second, respectively. Roll, pitch, and heading (otherwise known as the yaw of the aircraft) were reported in radians.

PAGE 57

57 Relative Time Altitude Airspeed Roll Pitch Heading GPS Heading GPS Latitude GPS Longitude 0 150.50 19.15 0.085 0.1 1.148 1.126 29.6848 81.95543 137 150.50 19.15 0.081 0.1 1.149 1.126 29.6848 81.95543 399 150.00 18.8 0.023 0.14 1.149 1.14 29.68483 81.95535 878 148.83 18.6 0.03 0.16 1.133 1.135 29.68487 81.95528 959 148.67 18.5 0.04 0.16 1.131 1.135 29.68487 81.95528 1388 147.83 18.55 0.07 0.17 1.101 1.105 29.6849 81.95519 1894 147.00 18.75 0.1 0.18 1.072 1.101 29.68491 81.95519 1963 146.67 18.85 0.11 0.18 1.064 1.07 29.68494 81.9551 2361 145.17 19.2 0.15 0.18 1.022 1.07 29.68494 81.9551 2400 144.83 19.15 0.16 0.18 1.015 1.07 29.68494 81.9551 2759 143.67 19.45 0.17 0.16 0.978 1.01 29.68498 81.95503 2879 143.33 19.6 0.18 0.16 0.966 1.01 29.68498 81.95503 3239 141.83 19.55 0.21 0.15 0.927 0.948 29.68502 81.95494 3320 141.50 19.55 0.21 0.15 0.919 0.948 29.68502 81.95494 3699 140.33 19.6 0.25 0.14 0.845 0.878 29.68507 81.95489 3801 140.00 19.65 0.25 0.13 0.827 0.878 29.68507 81.95489 4189 138.33 20 0.26 0.13 0.765 0.772 29.68512 81.9548 4302 138.00 20.05 0.28 0.12 0.75 0.757 29.68513 81.95479 4641 136.83 20.1 0.3 0.11 0.694 0.757 29.68513 81.95479 4700 136.33 20.2 0.3 0.1 0.676 0.692 29.68518 81.95474 5079 135.17 20.1 0.3 0.08 0.605 0.692 29.68518 81.95474 5203 134.83 20.05 0.32 0.07 0.592 0.612 29.68524 81.95467 5602 133.67 20.05 0.36 0.06 0.514 0.612 29.68524 81.95467 5668 133.50 20.05 0.37 0.05 0.503 0.522 29.6853 81.95461 6100 132.83 19.95 0.39 0.04 0.418 0.522 29.6853 81.95461 6151 132.67 20 0.4 0.04 0.424 0.522 29.6853 81.95461 6640 131.33 20.05 0.41 0.04 0.318 0.403 29.68538 81.95457 6863 130.83 20 0.41 0.04 0.266 0.271 29.68546 81.95453 7259 130.00 19.8 0.41 0.04 0.181 0.271 29.68546 81.95453 7386 129.83 19.75 0.42 0.03 0.159 0.167 29.68555 81.95451 7821 129.33 19.4 0.42 0.03 0.061 0.146 29.68557 81.95451 7878 129.33 19.25 0.42 0.04 0.049 0.057 29.68561 81.95449 8258 128.83 18.9 0.41 0.06 6.271 0.057 29.68561 81.95449 8300 128.83 18.85 0.4 0.06 6.263 0.057 29.68561 81.95449 8721 128.50 18.4 0.4 0.07 6.188 6.257 29.6857 81.95448

PAGE 58

58 8821 128.50 18.3 0.41 0.07 6.176 6.257 29.6857 81.95448 9241 127.83 18 0.42 0.09 6.099 6.165 29.68577 81.95448 9278 127.67 18 0.42 0.09 6.093 6.165 29.68577 81.95448 9681 127.17 17.7 0.44 0.1 6.032 6.074 29.68585 81.95448 9718 127.00 17.7 0.44 0.1 6.025 6.074 29.68585 81.95448 10120 126.00 17.5 0.43 0.11 5.959 5.972 29.68594 81.95449 10239 125.83 17.6 0.45 0.11 5.931 5.972 29.68594 81.95449 10686 124.83 17.6 0.46 0.12 5.847 5.872 29.68604 81.95454 10799 124.83 17.65 0.46 0.13 5.827 5.872 29.68604 81.95454 11239 123.67 17.6 0.48 0.13 5.749 5.768 29.68609 81.95457 11380 123.33 17.5 0.48 0.14 5.72 5.768 29.68609 81.95457 11799 122.17 17.3 0.44 0.13 5.625 5.672 29.68616 81.95461 11900 122.17 17.3 0.44 0.13 5.618 5.672 29.68616 81.95461 12339 121.17 17.25 0.49 0.13 5.521 5.584 29.68624 81.95467 12378 121.00 17.25 0.5 0.13 5.516 5.584 29.68624 81.95467 12760 120.17 17.1 0.53 0.14 5.422 5.457 29.6863 81.95474 12879 120.00 17.2 0.53 0.14 5.401 5.457 29.6863 81.95474 13220 118.83 16.7 0.53 0.15 5.305 5.457 29.6863 81.95474 13319 118.50 16.9 0.51 0.15 5.278 5.299 29.68636 81.95483 13660 117.50 17.25 0.54 0.15 5.197 5.272 29.68637 81.95486 13759 117.33 17.3 0.54 0.15 5.18 5.272 29.68637 81.95486 14179 116.00 17.5 0.55 0.13 5.079 5.174 29.68641 81.95491 14280 116.00 17.4 0.55 0.13 5.056 5.174 29.68641 81.95491 14703 114.83 17.15 0.53 0.13 4.951 5.032 29.68646 81.95501 14782 114.83 17.1 0.52 0.12 4.93 5.032 29.68646 81.95501 15259 114.00 17.2 0.51 0.12 4.819 4.886 29.68649 81.9551 15298 113.83 17.25 0.51 0.12 4.799 4.886 29.68649 81.9551 15720 113.17 17.1 0.53 0.12 4.735 4.759 29.6865 81.95523 15755 113.00 17.05 0.52 0.12 4.726 4.759 29.6865 81.95523 16211 112.50 16.8 0.5 0.12 4.649 4.675 29.68651 81.95532 16237 112.50 16.7 0.5 0.12 4.641 4.675 29.68651 81.95532 16708 112.17 16.4 0.51 0.14 4.519 4.568 29.68652 81.95545 16759 112.17 16.4 0.51 0.14 4.516 4.568 29.68652 81.95545 17159 111.50 16 0.52 0.15 4.426 4.451 29.6865 81.95554 17239 111.33 15.95 0.52 0.16 4.411 4.451 29.6865 81.95554 17661 110.83 15.65 0.52 0.17 4.331 4.361 29.68648 81.95565 17779 110.67 15.7 0.51 0.18 4.312 4.361 29.68648 81.95565 18200 110.00 15.55 0.54 0.19 4.218 4.255 29.68645 81.95574 18290 110.00 15.55 0.54 0.2 4.21 4.255 29.68645 81.95574

PAGE 59

59 18722 109.00 15.65 0.52 0.21 4.104 4.151 29.68641 81.95582 18860 108.67 15.7 0.52 0.21 4.08 4.151 29.68641 81.95582 19288 107.67 16 0.52 0.21 3.979 3.983 29.68635 81.95593 19319 107.50 16.05 0.52 0.22 3.969 3.983 29.68635 81.95593 19720 106.50 16.05 0.49 0.21 3.876 3.958 29.68634 81.95594 19758 106.50 16.1 0.48 0.21 3.866 3.958 29.68634 81.95594 20152 105.67 16.2 0.47 0.21 3.793 3.86 29.6863 81.95599 20177 105.50 16.2 0.47 0.2 3.783 3.86 29.6863 81.95599 20598 104.83 16.3 0.47 0.2 3.686 3.752 29.68623 81.95606 20703 104.67 16.3 0.46 0.19 3.691 3.752 29.68623 81.95606 21100 103.67 16.3 0.46 0.17 3.611 3.634 29.68614 81.95613 21239 103.17 16.2 0.46 0.16 3.577 3.634 29.68614 81.95613 21659 102.33 16 0.47 0.15 3.493 3.557 29.68608 81.95617 21759 102.33 16.05 0.47 0.15 3.48 3.557 29.68608 81.95617 22159 101.50 15.85 0.49 0.15 3.361 3.438 29.68598 81.9562 22197 101.50 15.85 0.49 0.15 3.351 3.438 29.68598 81.9562 22619 101.00 15.75 0.46 0.15 3.247 3.287 29.6859 81.95623 22702 100.83 15.7 0.45 0.14 3.22 3.287 29.6859 81.95623 23147 100.17 15.5 0.43 0.14 3.146 3.134 29.6858 81.95628 23240 100.17 15.55 0.43 0.14 3.128 3.134 29.6858 81.95628 23660 99.83 15.55 0.41 0.14 3.029 3.067 29.68575 81.95628 23697 99.83 15.55 0.42 0.14 3.025 3.067 29.68575 81.95628 24101 99.17 15.3 0.4 0.14 2.971 2.947 29.68565 81.95628 24138 99.00 15.25 0.4 0.14 2.963 2.947 29.68565 81.95628 24560 98.50 15.25 0.39 0.14 2.889 2.947 29.68564 81.95626 24679 98.33 15.25 0.38 0.13 2.858 2.947 29.68564 81.95626 25100 97.83 15.4 0.36 0.12 2.769 2.841 29.68555 81.95625 25138 97.67 15.45 0.36 0.12 2.746 2.841 29.68555 81.95625 25540 97.17 15.6 0.36 0.12 2.661 2.716 29.68548 81.95623 25680 97.17 15.55 0.35 0.12 2.652 2.716 29.68548 81.95623 26079 96.50 15.85 0.36 0.11 2.578 2.622 29.6854 81.95618 26179 96.50 15.85 0.36 0.11 2.576 2.622 29.6854 81.95618 26619 95.83 15.95 0.37 0.11 2.507 2.537 29.68534 81.95614 26657 95.83 15.95 0.37 0.11 2.512 2.537 29.68534 81.95614 27159 95.33 15.85 0.38 0.1 2.424 2.453 29.68526 81.9561 27259 95.17 15.85 0.37 0.1 2.407 2.453 29.68526 81.9561 27686 94.83 15.65 0.37 0.1 2.346 2.367 29.68521 81.95604 27761 95.00 15.65 0.37 0.1 2.328 2.367 29.68521 81.95604 28200 94.50 15.8 0.36 0.12 2.191 2.279 29.68516 81.95599

PAGE 60

60 28236 94.50 15.75 0.35 0.12 2.188 2.279 29.68516 81.95599 28661 94.33 15.45 0.32 0.12 2.162 2.13 29.68512 81.95591 28719 94.33 15.45 0.32 0.12 2.15 2.13 29.6851 81.95589 29143 93.67 16 0.34 0.13 2.05 2.112 29.68506 81.95583 29231 93.50 16.05 0.35 0.13 2.044 2.112 29.68506 81.95583 29670 92.83 16.4 0.34 0.11 1.999 2.008 29.68503 81.95576 29698 92.67 16.4 0.34 0.11 1.989 2.008 29.68503 81.95576 30098 91.83 16.55 0.35 0.1 1.942 2.008 29.68503 81.95576 30212 91.83 16.55 0.35 0.09 1.91 2.008 29.68503 81.95576 30620 91.33 16.65 0.34 0.1 1.777 1.944 29.68501 81.9557 30662 91.17 16.65 0.34 0.1 1.767 1.944 29.68501 81.9557 31118 90.83 16.45 0.28 0.08 1.746 1.76 29.68498 81.95561 31199 90.83 16.35 0.28 0.08 1.735 1.76 29.68498 81.95561 31639 90.17 16.6 0.29 0.07 1.681 1.726 29.68497 81.95552 31681 90.00 16.6 0.29 0.07 1.676 1.726 29.68497 81.95552 32098 89.67 16.6 0.32 0.07 1.62 1.649 29.68496 81.95544 32139 89.67 16.6 0.32 0.07 1.619 1.649 29.68496 81.95544 32540 88.83 16.9 0.36 0.06 1.55 1.58 29.68495 81.95535 32682 88.67 16.9 0.37 0.05 1.513 1.58 29.68495 81.95535 33086 88.17 16.8 0.39 0.05 1.42 1.456 29.68495 81.95526 33199 88.17 16.7 0.39 0.04 1.399 1.456 29.68495 81.95526 33585 88.17 16.55 0.38 0.04 1.309 1.319 29.68496 81.95518 33705 88.17 16.65 0.37 0.04 1.289 1.319 29.68496 81.95518 34102 88.00 16.55 0.37 0.05 1.192 1.202 29.68498 81.95513 34258 88.00 16.55 0.36 0.05 1.186 1.202 29.68498 81.95513 34660 88.00 16.35 0.33 0.05 1.142 1.117 29.685 81.95506 34783 88.00 16.35 0.32 0.06 1.128 1.117 29.685 81.95501 35221 88.00 16.35 0.32 0.05 1.07 1.092 29.68503 81.95495 35258 88.00 16.3 0.32 0.05 1.064 1.092 29.68503 81.95495 35659 87.50 16.55 0.34 0.05 1.005 1.092 29.68503 81.95495 36120 87.50 16.55 0.38 0.06 0.935 1.016 29.68505 81.95489 36232 87.50 16.65 0.38 0.06 0.913 1.016 29.68505 81.95489 36638 87.50 16.5 0.36 0.06 0.824 0.903 29.6851 81.95482 36681 87.50 16.5 0.36 0.06 0.82 0.903 29.6851 81.95482 37079 87.00 16.35 0.36 0.07 0.738 0.799 29.68514 81.95476 37178 87.00 16.35 0.35 0.07 0.743 0.799 29.68514 81.95476 37597 86.67 16.4 0.36 0.06 0.674 0.687 29.68519 81.95469 37645 86.83 16.35 0.36 0.06 0.667 0.687 29.68519 81.95469 38098 86.33 16.35 0.37 0.07 0.602 0.641 29.68523 81.95464

PAGE 61

61 38137 86.33 16.45 0.37 0.07 0.588 0.641 29.68523 81.95464 38598 85.83 16.55 0.37 0.05 0.514 0.536 29.68529 81.9546 38643 85.83 16.55 0.38 0.05 0.507 0.536 29.68529 81.9546 39217 85.33 16.8 0.37 0.05 0.393 0.454 29.68535 81.95456 39297 85.33 16.75 0.37 0.04 0.372 0.454 29.68535 81.95456 39738 85.17 16.7 0.37 0.05 0.314 0.338 29.68541 81.95454 39776 85.17 16.65 0.37 0.05 0.308 0.338 29.68541 81.95454 40218 85.00 16.55 0.35 0.04 0.23 0.271 29.68548 81.95451 40272 85.00 16.5 0.35 0.04 0.227 0.271 29.68548 81.95451 40719 84.67 16.55 0.31 0.04 0.147 0.185 29.68555 81.95446 40782 84.50 16.55 0.3 0.04 0.134 0.144 29.68556 81.95446 41158 84.00 16.45 0.31 0.03 0.047 0.144 29.68556 81.95446 41219 84.00 16.45 0.32 0.03 0.039 0.092 29.68561 81.95445 41659 83.67 16.25 0.35 0.02 6.249 0.092 29.68561 81.95445 41738 83.67 16.25 0.36 0.02 6.232 6.236 29.68569 81.95445 42158 83.67 16.15 0.35 0.02 6.155 6.236 29.68569 81.95445 42198 83.50 16.15 0.36 0.02 6.144 6.236 29.68569 81.95445 42597 83.33 15.95 0.38 0.01 6.069 6.131 29.68576 81.95445 42638 83.33 15.95 0.39 0.02 6.067 6.131 29.68576 81.95445 43020 83.33 15.9 0.37 0.01 5.997 6.034 29.68583 81.95446 43197 83.17 15.95 0.36 0.01 5.948 6.034 29.68583 81.95446 43637 83.00 15.95 0.34 0.01 5.896 5.904 29.68592 81.95448 43718 82.83 16 0.33 0 5.881 5.904 29.68592 81.95448 44213 82.50 16.1 0.33 0.005 5.81 5.84 29.68599 81.95451 44239 82.50 16.1 0.33 0.005 5.803 5.84 29.68599 81.95451 44716 82.17 16.5 0.36 0.022 5.722 5.764 29.68605 81.95456 44762 82.17 16.5 0.36 0.023 5.709 5.764 29.68605 81.95456 45218 82.17 16.45 0.4 0.033 5.652 5.665 29.68614 81.9546 45311 82.00 16.45 0.4 0.032 5.635 5.665 29.68614 81.9546 45756 82.00 16.35 0.44 0.031 5.56 5.591 29.6862 81.95464 45803 82.00 16.3 0.44 0.031 5.557 5.591 29.6862 81.95464 46237 82.33 16.15 0.46 0.02 5.443 5.505 29.68626 81.95472 46297 82.33 16.2 0.45 0.019 5.434 5.505 29.68626 81.95472 46679 82.33 16.5 0.45 0.008 5.361 5.505 29.68626 81.95472 46738 82.50 16.5 0.46 0.006 5.347 5.361 29.68632 81.9548 47197 82.33 16.7 0.46 0.013 5.219 5.361 29.68632 81.9548 47273 82.50 16.7 0.45 0.011 5.204 5.208 29.68638 81.95488 47738 83.17 16.75 0.44 0.01 5.114 5.182 29.68638 81.9549 47799 83.17 16.75 0.44 0.01 5.106 5.109 29.68642 81.95496

PAGE 62

62 48238 83.67 16.7 0.45 0.03 5.039 5.109 29.68642 81.95496 48298 83.67 16.7 0.45 0.03 5.028 5.032 29.68645 81.95505 48736 84.00 16.5 0.48 0.05 4.946 5.032 29.68645 81.95505 48774 84.17 16.45 0.48 0.05 4.938 5.032 29.68645 81.95505 49156 84.83 16.25 0.47 0.07 4.868 4.93 29.68647 81.95514 49195 84.83 16.2 0.47 0.07 4.857 4.93 29.68647 81.95514 49634 84.83 16.35 0.51 0.1 4.791 4.817 29.6865 81.95528 49682 85.00 16.35 0.51 0.11 4.776 4.817 29.6865 81.95528 50135 84.83 16.25 0.53 0.13 4.672 4.716 29.6865 81.95537 50234 85.00 16.15 0.52 0.14 4.647 4.716 29.6865 81.95537 50702 84.67 16.25 0.55 0.15 4.565 4.589 29.6865 81.95546 50780 84.50 16.4 0.55 0.15 4.542 4.589 29.6865 81.95546 51236 84.50 16.45 0.52 0.16 4.434 4.467 29.6865 81.95555 51274 84.50 16.45 0.52 0.16 4.428 4.467 29.6865 81.95555 51699 84.33 16.6 0.51 0.17 4.345 4.37 29.68648 81.95567 51861 84.17 16.6 0.52 0.17 4.305 4.37 29.68648 81.95567 52309 83.67 16.25 0.55 0.17 4.221 4.263 29.68645 81.95576 52417 83.67 16.1 0.55 0.17 4.193 4.263 29.68645 81.95576 52898 83.17 16 0.55 0.16 4.074 4.158 29.68642 81.95583 52976 83.17 15.8 0.55 0.16 4.053 4.158 29.68642 81.95583 53415 82.67 15.75 0.54 0.15 3.942 4.031 29.68637 81.95593 53456 82.67 15.75 0.54 0.15 3.928 4.031 29.68637 81.95593 53916 82.17 15.9 0.49 0.13 3.829 3.909 29.68632 81.956 53956 82.00 15.85 0.49 0.13 3.818 3.909 29.68632 81.956 54340 81.83 15.75 0.47 0.11 3.713 3.734 29.68624 81.95607 54437 81.83 15.75 0.47 0.11 3.692 3.734 29.68624 81.95607 54937 81.33 15.8 0.45 0.1 3.583 3.625 29.68617 81.95613 54956 81.33 15.75 0.45 0.09 3.564 3.625 29.68617 81.95613 55371 81.17 15.6 0.43 0.08 3.5 3.513 29.6861 81.95617 55397 81.17 15.55 0.43 0.08 3.488 3.513 29.6861 81.95617 55856 80.33 15.4 0.39 0.11 3.408 3.487 29.68609 81.95617 55956 80.17 15.35 0.38 0.12 3.393 3.401 29.686 81.9562 56357 79.50 15.3 0.38 0.15 3.331 3.401 29.686 81.9562 56395 79.50 15.3 0.39 0.15 3.326 3.401 29.686 81.9562 56817 79.00 15.45 0.41 0.2 3.29 3.309 29.6859 81.95623 56957 78.83 15.5 0.43 0.21 3.278 3.309 29.6859 81.95623 57397 78.00 15.55 0.46 0.25 3.205 3.275 29.68583 81.95625 57448 78.00 15.55 0.46 0.25 3.195 3.275 29.68583 81.95625 57835 76.83 15.85 0.47 0.27 3.088 3.178 29.68573 81.95628

PAGE 63

63 57880 76.67 15.85 0.47 0.27 3.08 3.178 29.68573 81.95628 58295 75.83 16.4 0.45 0.28 3.003 3.05 29.68568 81.95628 58375 75.50 16.4 0.46 0.28 2.985 3.05 29.68568 81.95628 58817 73.50 16.9 0.45 0.29 2.923 2.95 29.68561 81.95628 58956 73.17 17 0.46 0.28 2.903 2.95 29.68561 81.95628 59410 71.50 17.35 0.46 0.28 2.786 2.882 29.68552 81.95628 59436 71.17 17.35 0.46 0.27 2.77 2.882 29.68552 81.95628 59859 69.17 17.5 0.46 0.27 2.682 2.746 29.68543 81.95623 59934 68.50 17.6 0.47 0.26 2.666 2.746 29.68543 81.95623 60295 66.83 17.85 0.45 0.26 2.606 2.646 29.68536 81.95618 60335 66.67 17.95 0.44 0.26 2.595 2.646 29.68536 81.95618 60755 65.00 18.25 0.45 0.25 2.503 2.561 29.68529 81.95614 60796 64.83 18.25 0.45 0.25 2.492 2.561 29.68529 81.95614 61179 63.17 18.5 0.45 0.25 2.419 2.447 29.68523 81.95609 61215 63.00 18.5 0.45 0.25 2.41 2.447 29.68523 81.95609 61674 61.00 18.55 0.48 0.25 2.313 2.344 29.68516 81.95603 61777 60.83 18.55 0.48 0.25 2.301 2.344 29.68516 81.95603 62175 59.00 19 0.46 0.25 2.201 2.344 29.68516 81.95603 62275 58.50 19 0.46 0.25 2.177 2.232 29.68511 81.95596 62738 56.83 19.1 0.47 0.25 2.078 2.083 29.68505 81.95587 62775 56.67 19.1 0.47 0.25 2.069 2.083 29.68505 81.95587 63217 54.83 19.35 0.43 0.24 1.969 2.083 29.68505 81.95587 63635 53.17 19.5 0.44 0.24 1.892 1.935 29.685 81.95576 63683 53.00 19.55 0.43 0.24 1.886 1.935 29.685 81.95576 64117 51.17 20.1 0.41 0.23 1.827 1.866 29.68497 81.95568 64152 51.00 20.1 0.41 0.23 1.818 1.866 29.68497 81.95568 64594 49.67 19.85 0.43 0.23 1.734 1.78 29.68495 81.95559 64634 49.50 19.9 0.43 0.23 1.721 1.78 29.68495 81.95559 65019 48.00 20.3 0.44 0.22 1.652 1.667 29.68494 81.95548 65156 47.83 20.3 0.44 0.22 1.637 1.667 29.68494 81.95548 65576 46.17 20.35 0.47 0.22 1.547 1.581 29.68493 81.95541 65615 46.00 20.4 0.47 0.22 1.555 1.581 29.68493 81.95541 66035 44.50 20.1 0.49 0.23 1.489 1.502 29.68492 81.95529 66135 44.00 19.9 0.49 0.23 1.475 1.502 29.68492 81.95529 66539 42.50 19.05 0.39 0.26 1.421 1.429 29.68493 81.9552 66665 42.17 18.8 0.34 0.27 1.384 1.429 29.68493 81.95518 67114 40.67 18.2 0.19 0.28 1.34 1.344 29.68494 81.95509 67155 40.50 18.2 0.17 0.28 1.351 1.344 29.68494 81.95509 67578 39.00 18.4 0.01 0.3 1.344 1.342 29.68495 81.95504

PAGE 64

64 67625 39.00 18.4 0 0.3 1.366 1.342 29.68495 81.95504 68057 36.83 18.2 0.087 0.3 1.416 1.342 29.68495 81.95501 68134 36.33 18.2 0.089 0.3 1.418 1.396 29.68497 81.95493 68534 34.17 17.9 0.083 0.3 1.487 1.396 29.68497 81.95493 68683 33.50 17.7 0.07 0.3 1.485 1.495 29.68497 81.95486 69121 32.00 17.6 0.01 0.31 1.497 1.495 29.68497 81.95486 69154 31.83 17.6 0.01 0.32 1.497 1.495 29.68497 81.95486 69586 29.00 17.65 0.012 0.29 1.525 1.514 29.68498 81.95478 69614 28.50 17.65 0.006 0.29 1.546 1.514 29.68498 81.95478 70057 27.17 17.65 0.08 0.3 1.567 1.562 29.68498 81.95467 70095 26.83 17.6 0.08 0.3 1.541 1.562 29.68498 81.95467 70516 25.17 16.75 0.02 0.28 1.552 1.548 29.68499 81.95462 70684 24.50 16.5 0.09 0.28 1.533 1.548 29.68499 81.95462 71096 22.17 17 0.03 0.27 1.54 1.535 29.68499 81.95454 71135 22.00 17.1 0.03 0.27 1.52 1.535 29.68499 81.95454 71562 20.00 17.4 0 0.29 1.504 1.51 29.685 81.95446 71666 19.33 17.25 0.031 0.29 1.516 1.51 29.685 81.95446 72075 18.33 16.95 0.001 0.29 1.517 1.52 29.685 81.95436 72174 17.83 16.95 0.005 0.31 1.529 1.52 29.685 81.95436 72594 15.00 16.5 0.031 0.28 1.539 1.528 29.685 81.95429 72675 14.50 16.4 0.033 0.29 1.547 1.528 29.685 81.95429 73093 12.33 15.9 0.017 0.31 1.64 1.627 29.685 81.95419 73130 12.00 15.9 0.017 0.31 1.651 1.627 29.685 81.95419 73579 10.33 16.2 0.014 0.34 1.935 1.846 29.685 81.95413 73658 10.00 16.25 0.019 0.34 1.716 1.846 29.685 81.95413 74156 7.67 17.3 0.067 0.34 1.597 1.771 29.685 81.95402 74193 7.50 17.3 0.063 0.34 1.58 1.771 29.685 81.95402 74596 4.50 17.2 0.022 0.3 1.504 1.393 29.68501 81.95393 74694 4.00 17.2 0.026 0.3 1.478 1.393 29.68501 81.95393 75099 0.83 17.15 0.075 0.28 1.357 1.362 29.68501 81.95385 75136 0.17 16.95 0.073 0.28 1.554 1.362 29.68501 81.95385 75534 0.17 12.35 0.246 0.17 1.62 1.362 29.68501 81.95385 75669 0.17 10.9 0.281 0.06 1.705 1.614 29.685 81.95377 76103 0.17 1.8 0.056 0.36 2.257 1.804 29.68499 81.95375 76155 0.67 5.7 0.036 0.36 1.886 2.232 29.685 81.95368 76615 0.17 3.3 0.073 0.37 1.717 2.232 29.685 81.95368 76687 0.17 2.95 0.079 0.37 1.718 1.939 29.68499 81.95364 77094 0.00 1.8 0.052 0.33 1.711 1.939 29.68499 81.95364 77159 0.17 1.8 0.049 0.32 1.708 1.711 29.68498 81.95364

PAGE 65

65 77594 0.00 1.6 0.031 0.27 1.696 1.711 29.68498 81.95364 77633 0.00 1.6 0.031 0.27 1.696 1.711 29.68498 81.95364 78033 0.17 0.85 0.018 0.23 1.691 1.694 29.68498 81.95364 78137 0.33 0.8 0.015 0.22 1.689 1.694 29.68498 81.95364 78555 0.33 0.3 0.005 0.19 1.686 1.69 29.68498 81.95364 78594 0.33 0.5 0.004 0.19 1.685 1.69 29.68498 81.95364 79075 0.17 0.4 0.01 0.16 1.68 1.685 29.68499 81.95364 79115 0.33 0.25 0.01 0.15 1.679 1.685 29.68499 81.95364 79514 0.33 0.9 0.01 0.13 1.674 1.678 29.68499 81.95365

PAGE 66

66 LIST OF REFERENCES 1 Evers, B. S. , "Improving Operational Efficiency of Small Unmanned Aircraft Systems for Remote Sensing Applications," Master's Thesis , University of Florida, 2011. 2 Perry, J. H. , "A Synthesized Directly Georeferenced Remote Sensing Technique for Small Unmanned Aerial Vehicles , " Master' s Thesis, University of Florida, 2009. 3 Sasse, D. B., "Job related mortality of wildlife workers in the United States, 1937 2000," Wildlife Society Bulletin , 2003. 4 Gundlach, J., Designing Unmanned Aircraft Systems: A Comprehensive Approach , AIAA Education Series , Reston, V A, 2012. 5 Houghton, E. L., Carpenter, P. W., Aerodynamics for Engineering Students, Fifth Edition, Butterworth Heinemann, Boston, MA, 2003. 6 Pierson B. L., Chen, I., "Minimum Landing Approach Distance for a Sailplane," Journal of Aircraft , Vol. 16, No.4 , 1979, pp. 287 288 . 7 Corda, S., Stephenson, M. T., Burcham, F. W., Curry, R. E., "Dynamic Ground Effects Flight Test of an F 15 Aircraft,". NASA Technical Memorandum 4604, 1994. 8 Gratzer, L. B., Mahal, A. S., " Ground Effects in STOL Operation," Journal of Aircraft , Vol. 9, No. 3, 1972, pp. 236 242. 9 Halloran, M., O'Meara, S., "Wing in Ground Effect Craft Review," DSTO Aeronautical and Maritime Research Laboratory, 1999. 10 O'Leary, C. O., "Flight Measurements of Ground Effect on the Lift and Pitching Moment of a Large Tra nsport Aircraft (Comet 3B) and Comparison with Wind Tunnel and Other Data," Ministry of Technology Aeronautical Research Council, 1969. 11 Zerihan, J., Zhang X., "Aerodynamics of a Single Element Wing in Ground Effect," Journal of Aircraft , Vol. 37, No. 6 , 2000, pp. 1058 1064. 12 Yechout, T. R., Introduction to Aircraft Flight Mechanics, AIAA Education Series, Reston, VA , 2003. 13 Austin, R., Unmanned Aircraft Systems: UAVS Design, Development and Deployment, John Wiley & Sons Ltd., Hoboken, N.J , 2013. 14 Smith, A. M. O., "High Lift Aerodynamics," Journal of Aircraft , Vol. 12, No. 6, 1976, pp. 501 530

PAGE 67

67 15 Hansen, J. R. The Bird Is on the Wing: Aerodynamics and the Progress of the American Airplane. Texas A&M University Press, 2003. 16 Young, A. D., "The Ae rodynamic Characteristics of Flaps," Ministry of Supply Aeronautical Research Council, 1947. 17 Rogers, D. F., "Flight Determination of Partial Span Flap Parasite Drag with Flap Deflection," Journal of Aircraft , Vol. 47, No. 2, 2010, pp. 551 555 18 Anderson, J. D., Fundamentals of Aerodynamics , McGraw Hill, New York, NY, 1984. 19 Rogers, D. F., "Absolute Angle of Attack," NAR Associates, 2010b. 20 Corke, T. C., Design of Aircraft, P rentice Hall , Pearson Education, Upper Saddle River, NI, 2003. 21 Ab bott, I. H., von Doenhoff, A. E., Theory of Wing Sections: Including a Summary of Airfoil Data, McGraw Hill Book Co., Inc., New York, NY, 1949. 22 Lovell, D. A., "A Wind Tunnel Investigation of the Effects of Flap Span and Deflection Angle, Wing Planform and a Body on the High Lift Performance of a 28° Swept Wing," Aeronautical Research Council, 1976. 23 Hurt, H. H. Aerodynamics for Naval Aviators. The Office of the Chief of Naval Operations, Aviation Training Division, 1965. 24 Kluga N. R., "A Study of Fl ap Management, an Analysis of the Consequences of Flap Management, and a Search for Possible Causes," The Journal of Aviation/Aerospace Education & Research , Vol. 1, No. 3, 1991 . 25 Cavanaugh, M. A., Robertson, P, Mason, W. H., " Wind Tunnel Test of Gurney Flaps and T Strips on an NACA 23012 Wing," 25th AIAA Applied Aerodynamics Conference, 2007. 26 Maughmer, M. D., Bramesfeld, G., "Experimental Investigation of Gurney Flaps," Journal of Aircraft , Vol. 45, No. 6, 2008, pp. 2062 20 67. 27 McKinney E. G., Purser, P. E., "Comparison of Pitching Moments Produced by Plain Flaps and Spoilers and Some Aerodynamic Characteristics of an NACA 23012 Airfoil with Various Types of Aileron.," NACA, 1945. 28 Wrick, F. E., Shortal, J. A., "The Effect of Multiple Fixed Slots and a Trailing Edge Flap on the Lift and Drag of a Clark Y Airfoil," NACA, 1933.

PAGE 68

68 29 Zabloudil, M. , Patek, Z., Vrchota, P., "Wind Tunnel Investigation of Flowfield on the Fowler Flap and in the Cove Using PIV Method," 27 th International Congress of the Aeronautical Sciences, 2010. 30 Abbott, I. H., " Lift and Drag Characteristics of a Low Drag Airfoil with Slotted Flap Submitted by Curtiss Wright Corporation," NACA, 1941. 31 Jung, U. S.," Alternative Air Brake Concepts for Transport Aircraft Steep Approach," Ph.D Dissertation, Technical University of Munich, 2011. 32 Karagounis, T. , "Static and Dynamic Leading Edge Flap Effects on the Vortex Lift of a Delta Wing," Ph.D Dissertation, Univers ity of Southern California, 1997. 33 Kanjere, K., Zhang, X., Hu, Z., Angland, D., " Aeroacoustic Investigation of Deployed Spoiler During Steep Approach Landing," 16th AIAA/CEAS Aeroacoustics Conference, 2010. 34 Mashud M., Ferdous, M., Omee, S. H., "Effect of Spoiler Position on Aerodynamic Characteristics of an Airfoil," International Journal of Mechanical and Mechantronics Engineering , Vol. 12, No. 6, 2012, pp.1 6. 35 Kohlman, D. L., Brainerd, C. H., "Evaluation of Spoilers for Light Aircraft Flight Path Control," Journal of Aircraft , Vol. 11, No. 8, 1974, pp.449 456. 36 Davies, H., Kirk, F. N., "A Resume of Aerodynamic Data on Air Brakes," Ministry of Supply Aeronautical Research Council, 1942. 37 Mertol, B. A., "An Airbrake Design Methodology for Steep Approaches," New Results in Numerical and Experimental Fluid Mechanics VI, Springer Berlin Heidelberg, 2008, pp.1 8. 38 Patek, Z., Cervinka, J., Vrchota, P . , "Wing Tunnel and CFD Study of Airfoil with Airbrake," 28 th International Congress of the Aeronauti cal Sciences , 2012. 39 Bertin, J. J., Cummings, R. M., Aerodynamics for Engineers, Pearson Hall, Upper Saddle River, NJ , 2008. 40 Chopde, N. R., Nichat, M. K., "Landbased Shortest Path Detection by Using A* and Haversine Formula ," International Journal of Innovative Research in Computer and Communication Engineering , Vol. 1, No. 2, 2013, pp. 298 302.

PAGE 69

6 9 BIOGRAPHICAL SKETCH Abraham Balmori was born and raised in Miami Lakes, FL. Growing up two miles from a municipal airport , Abraham discovered the wonders of flight at an early age. Upon graduation from Monsignor Edward Pace High School in Opa Locka, FL, Abraham was admitted to the University of Florida to pursue a dual degree in Mechanical and Aerospace Engineering. While attending engineering courses, Abr aham joined the Design/Build/Fly competition team to further broaden his experience on working with small scale aerial vehicles. He served as the team leader in the 2011 /12 competition year, sharpening his leadership skills while continuing to the basics o f aircraft design. While working on the DBF team, Abraham also volunteered at the Micro Air Vehicles lab under the direction of Dr. Peter G. Ifju where he first learned how to work with composite materials to build durable, light airframes. After obta ining his Bachelor of Science d egrees, Abraham pursued a Master of Science degree in aerospace e ngineering. Abraham joined the UF UASRG to expand upon his knowledge of UAV construction, design, and implementation. In addition to maintaining the Nova 2.1 fleet, Abraham also served as an observer for field missions and helped develop new techniques for fabricating stronger, ergonomic UAVs. He was also a teaching assistant for two courses in the Mechan ical and Aerospace Engineering D epartment . Beyond his passion for aerial vehicles, Abraham also enjoys driving and maintaining his 1966 Chevrolet pickup t ruck, b iking, and traveling. Whenever time permits, he enjoys traveling to the Florida Keys to snorkel and spend time with his family.