A RETROSPECTIVE: DEVELOPMENT OFSIMULATION MODELS FOR THE 1903 AND

1905 WRIGHT FLYERS

Robert W. Deters,∗ Benjamin A. Broughton,† and Michael S. Selig‡

Department of Aerospace EngineeringUniversity of Illinois at Urbana–Champaign

Urbana, Illinois 61801

The centennial of flight has brought about a renewed interest in the first airplanesand their flight characteristics. It is known that the first Wright Flyers were unstable,but history showed that they were flyable. It is the longitudinal handling characteristicsthat are of interest in this paper. Wind tunnel tests have been performed on the 1903Flyer and provide limited aerodynamic data, but a higher fidelity model is needed tofully simulate the aircraft within nonlinear regions. Simulation models of the 1903 and1905 Flyers were created by using the results of wind tunnel tests, using inviscid flowanalysis, and expanding the data to include high angles of attack. The two models weresimulated in the PC-based FlightGear Flight Simulator, and the results show that bothaircraft require continuous pilot input, but they are flyable with practice.

IntroductionOn December 17, 1903 the world changed as two bi-

cycle shop owners made their first flight in an airplanethey designed and built themselves. The first flightonly lasted 12 sec and for a distance of about 120 ft,but it was enough to show that the years of researchand design the Wright brothers conducted successfullyled to a flyable machine. The brothers were very sys-tematic to the design of their aircraft. They usedgliders and airfoils tested in their own wind tunnel totest and modify their designs. Using what they learnedfrom their first attempt, the Wright Brothers went onto design several more Flyers, one of which was the1905 Flyer.

Now on the centennial of that first flight, technol-ogy has made it possible to simulate the first WrightFlyers on desktop PCs. It was the authors’ goal to cre-ate high fidelity, nonlinear simulation models for boththe 1903 and 1905 Flyers. The two aircraft are notonly historically interesting, but also their designs arequite unusual compared to modern conventional de-signs. The longitudinal handling qualities of the twoFlyers are known to be difficult, so simulation modelswere created in order to be able to study and comparethe them. While the two aircraft are similar in de-sign and static margin, Papachristodoulou and Culick1

noted an increase in the pitch damping coefficient dueto the larger canard on the 1905 Flyer.

∗Graduate Research Assistant, Student Member AIAA.rdeters@uiuc.edu

†Graduate Research Assistant, Student Member AIAA.bbrought@uiuc.edu

‡Associate Professor, Senior Member AIAA.m-selig@uiuc.edu.

Nonlinear aerodynamic models were created for the1903 and 1905 Flyers using data from an inviscid flowanalysis of the wing and canard and data from windtunnel tests on full- and sub-scale models of the 1903Flyer. These models were integrated into the Flight-Gear Flight Simulator.2 Simulated flights of thesemodels demonstrate that constant attention is neededto keep these aircraft in the air, but the 1905 Flyer ismuch easier to control than the 1903 Flyer.

In this paper, a brief history of the two flyers is firstpresented, followed by a description of the inviscid flowanalysis method and the flight simulator. A discus-sion of the development of the two simulation modelsis then presented, where the method of obtaining theaerodynamic data is addressed. Finally, results fromsimulation of the two Wright Flyers are presented.

Brief History of the Two FlyersThe history of the two Flyers is well documented, so

that only a brief history of the two Flyers is given tobetter understand why these aircraft warrant analysis.

1903 Wright Flyer

At the beginning of the twentieth century, flight wason the brink of being obtained. People all over theglobe were trying with varying degrees of success tobecome the first in flight. It took two bicycle shopowners from Dayton, Ohio to make this dream a real-ity.

The Wright brothers approached flight in a mannerdifferent than most of their contemporaries. Beforebuilding an aircraft that could fly, they first designed asystem that could control the aircraft. This approachled them to the use of gliders as testing platforms.The brothers had a good base of information available

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to them from such researchers as Otto Lilienthal andOctave Chanute from which to start their own experi-ments.3,4 From their gliders, they were able to design,test, and refine their ideas.

Leading to their invention of the airplane, theWright brothers made several important discoveriesand innovations. Their early glider tests demonstratedthat the lift they were producing was less than pre-dicted. In order to acquire necessary aerodynamicdata, the brothers built their own wind tunnel andsystematically tested airfoils and planforms to pro-vide data they required. To control the rolling of theaircraft, the brothers devised a system to warp thewing tips thus increasing and decreasing the lift onthe wings to induce a rolling moment. Testing of sucha wing warping system led the Wrights to the discov-ery of adverse yaw. While using the warping systemto initiate a turn, the nose of the glider would yawin the opposite direction. To counteract this behav-ior, the brothers first used a stationary and then latera movable rudder. Another innovation of the Wrightbrothers was their method of propeller design. Thebrothers realized that a propeller for an aircraft doesnot behave in the same manner as one for a boat. In-stead of propelling an aircraft by just moving air, apropeller is a rotating wing that creates a lifting forcein the horizontal direction. Using their own propellertheory and wing tunnel tests of different airfoils, thebrothers were able to design propellers unlike any inexistence at that time.5 Their method of tackling theproblem of flight has rightfully given them the honoras the first aeronautical engineers.6

All of the knowledge the Wright brothers learnedfrom their glider tests was used to create their firstFlyer in 1903. The design of this airplane is unusualcompared to conventional modern designs. Figure 1shows a three-view of the aircraft. It is a biplane de-sign with a biplane canard and twin rudder. The winghas a span of 40.3 ft, a chord of 6.5 ft, and an areaof 510 ft2. The canard has a span of 12 ft, a chordof 2.5 ft, and an area of 48 ft2. The rudder has anaverage span of 6.9 ft, a chord of 1.5 ft, and an areaof 20 ft2. The aircraft weighs 605 lbs without a pi-lot, and according to Papachristodoulou and Culick,1

the center of gravity is located 29.7% of chord behindthe leading edge of the wing and the neutral point islocated 3.9% of chord behind the leading edge.

On December 17, 1903 at 10:35 am, Orville Wrightin the 1903 Flyer became the first in flight when theairplane lifted off the ground and flew for 120 ft in12 sec (Fig. 2). Three more flights were made with thefourth being the longest at 852 ft in 59 sec. Because ofits significance, the original 1903 Flyer is now proudlydisplayed at the National Air and Space Museum inWashington, DC.

Fig. 1 Three-view of the 1903 Wright Flyer (Li-brary of Congress).

Fig. 2 First flight of the 1903 Wright Flyer.

1905 Wright Flyer

After the success of the 1903 Flyer, the Wrightbrothers returned to Dayton, Ohio to improve on theirdesign. They knew that if they were going to selltheir airplanes, they would need a design that wouldstay in the air much longer than one minute. For the1904 and early 1905 Flyers, the brothers used a designclose to the 1903 Flyer. They tested these airplanesat Huffman Prairie close to Dayton. Unfortunatelythe brothers did not see much improvement in theirflight performance while at this test site during Juneand July of 1905. Flights were short with the longestonly being about 20 sec.7 On July 14 with Orville atthe controls, the 1905 Flyer suffered a terrible crashdestroying large parts of the Flyer.

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Fig. 3 Three-view of the 1905 Wright Flyer (Li-brary of Congress).

The crash forced the Wrights to address the pitchinstability in their airplane that sometimes caused itto be uncontrollable. Keeping the wings similar to the1903 Flyer, the brothers rebuilt the forward part of theairplane to improve the pitch instability. The area ofthe 1905 canard was increased from 52.75 ft2 to 83 ft2,and the distance between the wing and canard wasincreased from 7.32 ft to 11.7 ft.7 Figure 3 shows athree-view of the new design. The wing has a span of40.5 ft, a chord of 6.5 ft, and an area of 503 ft2. Thecanard has a span of 15.6 ft, a chord of 3.1 ft, andan area of 83 ft2. The rudder has a span of 7 ft, achord of 2.5 ft, and an area of 34.8 ft2. The aircraftweighs 710 lbs without a pilot, and according to Pa-pachristodoulou and Culick.,1 the center of gravity islocated 12.8% of chord behind the leading edge of thewing and the neutral point is located 14.6% of chordin front of the leading edge.

The aircraft was back in the air at the end of August,and the new design showed tremendous improvementin performance. The brothers were soon able to fly forminutes at a time, and flight time steadily increased

Fig. 4 1905 Wright Flyer above Huffman Prairie(McFarland3).

over the next month. By the beginning of October,flights were lasting around 30 minutes. Their longestflight was on October 5, 1905 when Wilbur flew theFlyer for 24 miles in 39 min 23.8 sec. Now the Wrightbrothers had a practical airplane. Figure 4 shows the1905 Flyer in the air above Huffman Prairie. The 1905Flyer is now on display at the Carillon Historical Parkin Dayton, Ohio.

Development ToolsInviscid Flow Analysis

Inviscid flow analysis of the 1903 and 1905 WrightFlyers was performed using CMARC.8 CMARC is aC++ port of the Fortran code PMARC.9 These twocodes implement a low-order panel method that usesconstant strength doublet and source panels placed onthe surface of the body to be modeled. An internalDirichlet boundary condition is used, while the wake ismodeled using constant-strength doublet panels. Theaerodynamic forces are calculated by integrating thepressures over all the surface panels, while a more ac-curate induced drag coefficient can be calculated usinga Trefftz plane analysis. All the models in the cur-rent study used planar wakes oriented parallel to thefree-stream flow direction. Only the right half of thegeometry was modelled explicitly, and the flowfield wasassumed to be symmetrical in the xz-plane. The flowanalysis was performed with the wing and canard sec-tions in isolation. The wing analysis was also usedto obtain the induced velocities at the location of thecanard aerodynamic center.

The airfoils used for the panel model were obtainedby scanning and digitizing accurate blueprints of the1903 and 1905 Wright Flyers. The original WrightFlyers had fairly blunt leading and trailing edges onthe canards, so that the leading edges of the canardairfoils had to be slightly rounded for the inviscid flowanalysis, while the trailing edges were modified to asharp point. The trailing edge of the main wing air-foil was similarly modified from a finite thickness to a

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1903 Canard

1905 Canard

1903 and 1905 Wing

Fig. 5 Airfoils used for CMARC panel mesh.

X Y

Z

Fig. 6 Mesh for the 1905 wing.

point. The airfoils used for the flow analysis are shownin Fig. 5.

The panel mesh was generated using a custom sur-face modeler and mesh generator. Although the 1903and 1905 Wright Flyers have very similar wings, the1903 Flyer had a small amount of anhedral that wasremoved for the 1905 aircraft. The anhedral on the1903 wing was modeled using a linear deflection alongthe span. It is believed that this simplification overthe actual deflection shape has a negligible effect onthe longitudinal stability and control characteristics.The mesh generator was also used to deflect the canardsurfaces to simulate elevator input from the pilot. Themesh for the wing of the 1905 Flyer is shown in Fig. 6.The mesh uses a cosine panel distribution in the chord-wise direction and a linear distribution in the spanwisedirection over both the inner and the tip sections. Theupper and lower wing each used 1280 panels for a to-tal of 2560 panels to model the entire wing geometry.The canards combined also used a total of 2560 surfacepanels. Examples of the 1903 and 1905 canard panelmeshes are shown in Figs. 7 and 8, respectively.

FlightGear Flight Simulator

The 1903 and 1905 Wright Flyer models were imple-mented and tested using the FlightGear Flight Sim-ulator (FGFS),2 a cross-platform, open-source, PC-based flight simulator written in C/C++ and utilizingOpenGL graphics. In conjunction with the NASASmart Icing Systems project,10 the authors helped in

X Y

Z

Fig. 7 Mesh for the 1903 canard.

X Y

Z

Fig. 8 Mesh for the 1905 canard.

modifying FGFS to create a reconfigurable aircraftmodel11 based on the NASA Langley LaRCsim flightdynamics module.12 The reconfigurable aircraft modelallows for the simulation of a model by specifying air-craft characteristics in an input file. Data requiredby the input file includes the geometry, mass, aero-dynamic model, engine model, and gear model of theaircraft. The nonlinear aerodynamics models used forthe 1903 and 1905 Flyers use a combination of stabil-ity and control derivatives and lookup tables. Figures9 and 10 show typical images of the 1903 Wright Flyerand the 1905 Wright Flyer, respectively, in FlightGear.

Model DevelopmentIn the development of the flight model, emphasis was

placed on synthesizing data that properly character-ized the handling qualities in longitudinal flight. Nev-ertheless, a full six degree-of-freedom aircraft modelwas developed to simulate lateral-directional flyingqualities and ground reactions. Only a simple thrustmodel was implemented, sufficient for flight, and aero-

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Fig. 9 Front perspective view of the 1903 WrightFlyer in FlightGear.

Fig. 10 Front perspective view of the 1905 WrightFlyer in FlightGear.

dynamic ground effects were ignored.For the aerodynamics model, the stability axis sys-

tem was used, and the conventional approach wastaken as described. The three components of the lon-gitudinal mode of the aerodynamic model were func-tions of the angle of attack, canard deflection, andpitch rate. The lateral-directional components werefunctions of the sideslip angle, wing warping, rudderdeflection, roll rate, and yaw rate. Each componentof the aerodynamic model took the form of a coeffi-cient build up where the coefficient was constructed ofa base part and several incremental parts. The basepart is the value of the coefficient with no control sur-face deflections or angular rates. The base parts of thelongitudinal components were a function of the angleof attack, and the lateral-directional components werea function of sideslip angle. Incremental parts dueto control surface deflections and angular rates werethen added to their respective base parts as is stan-dard practice in flight simulation modeling.

Data used in generating the flight model was de-rived from several sources. First, drawings of the 1903and 1905 Flyers were obtained13,14 and used for massand geometry information. Also, invaluable experi-mental data were obtained from wind tunnel tests ona full-scale replica of the 1903 Flyer tested at NASAAmes.15 Augmenting these experimental results werethe predictions derived from CMARC as previously de-scribed. The aforementioned experimental results and

the validity of the predictions were limited to angles ofattack for which there was limited flow separation—in the first case due to structural concerns and in thelatter due to the assumption of inviscid flow. Thus,nonlinear data into the stalled flight regime had to becreated based on trends gleaned from a diverse collec-tion of literature on stalled wings (not all of which iscited in this paper).

The approach taken to modeling the longitudinalaerodynamics was to consider the biplane wing andcanard separately. Thus, in the simulation the canardcan stall independently of the biplane main wing. Up-wash effects on the canard due to the main wing areincluded in realtime in the simulation based on thecirculation strength of the main wing. No influence ofthe canard on the main wing was considered.

The main biplane wing was analyzed in isolation inCMARC, and the results are shown in Fig.11. As seenthe effects of separation leading to stall are not mod-eled by the panel method. Also, shown in Fig.11 arethe lift data from the NASA Ames Tests.15 This windtunnel test data is only that shown between the twobullet symbols. The agreement between the CMARCruns and the NASA data is seen to be quite good,with discrepancies likely due to the effects of non-idealflow, the presence of the Canard and also perhaps,as has been suggested,16 deformation of the fabric.Departures from the CMARC data and NASA Amesdata have been estimated based on the stall behav-ior of biplane wings,17 wind tunnel test data shown inRef. 16, and 2D stall characteristics of thin camberedairfoils. Pitching moment data for the main wing isshown in Fig. 12, and the nonlinear aerodynamics havebeen estimated as previously described. In the simu-lation the lift and moment data from the solid linesin Figs. 11 and 12 were used. Drag data for the mainwing was deduced from the NASA Ames tests,15 andwill be presented later. (But again it should be addedthat modeling drag and its thrust counterpart weresomewhat secondary goals of this work that centeredaround interest in the longitudinal handling qualities.)

As with the main biplane wing, the canard con-tributes lift, drag and moment to the overall aerody-namics. The most important contribution, however,derives from the lift on the canard and at high anglesof attack the chordwise normal force on the canardas these forces produce the necessary control momentsfor trimmed flight. Figure 13 shows the CMARC pre-dictions for the lift coefficient as a function of canarddeflections ranging from −30 to 30 deg. (The givenlift coefficients were nondimensionalized by the canardarea of 48 ft2.) Based on the airfoil used on the ca-nard, stall was estimated to occur at CL ∼ −0.5 and0.9. Data beyond stall is representative of the normalforce coefficient, which has an important contributionto the total pitching moment of the aircraft in the non-linear flight regime. The solid line force coefficient data

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CMARC

c = 5.1 deg

c = -4.6 degc = -0.1 deg

δδδ

NASA Ames Data

CL,sim

-10 0 10 20-0.5

0

0.5

1

1.5

w (deg)

CL,w

α

Fig. 11 Lift coefficient versus angle of attack fromCMARC and wind tunnel tests for the main bi-plane wing.

CMARC

Cm,sim

-10 0 10 20-0.2

-0.1

0

w (deg)

Cm,w

α

Fig. 12 Pitching moment coefficient versus angleof attack for the main biplane wing of the 1903Flyer.

shown in Fig. 13 was then used to determine the con-trol power of the canard, which is shown in Fig. 14.In the simulation only the solid lines are used. Thecanard contribution to the overall lift is not explicitlyincluded as that contribution has already been embod-ied in the lift data shown in Fig. 11. Likewise, the draghas been included in the total aircraft drag measuredin the NASA Ames data used in this work.

It is worth mentioning that when the main wingand canard pitching moment contributions are added(taking into account upwash effects on the canard) theresults are in quite good agreement with the NASAAmes data.15 Of course the result is that the 1903Flyer is statically unstable as has been well docu-mented in the literature.

For the 1903 Flyer, the canard deflection limitshave not been reported in the literature nor in the

CMARC

0

7.5

c = 30 deg

15

-7.5

-15

c = -30 degδ

δ

-10 0 10 20-1

-0.5

0

0.5

1

1.5

c (deg)

CL,c

Cn,c

α

Fig. 13 Lift coefficient versus angle of attack forthe 1903 canard at canard deflection angles rangingfrom −30 to 30 deg.

c = 30 degδ

15

7.5

0

-7.5

-15

c = -30 degδ

CMARC

-10 0 10 20-0.1

0

0.1

0.2

c (deg)

Cm,c

α

Fig. 14 Pitching moment coefficient versus angleof attack for the 1903 canard at canard deflectionangles ranging from −30 to 30 deg.

blueprints of the Smithsonain.13 Inspection of Fig. 2showing the first flight contains important informa-tion on canard deflection, which appears to be quiteextreme at the given instant. Using the simulation 3Dgraphics model, trial and error was used to set the ca-nard deflection at an angle that most closely matchedthat shown in Fig. 2. The resulting match appears inFig. 15, which was generated using a canard deflection

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Fig. 15 View of the 1903 Wright Flyer with a30 deg canard deflection in FlightGear.

CL,w

CD

Cm,w

Cm,c

-90 -45 0 45 90-1

-0.5

0

0.5

1

1.5

(deg)α

Fig. 16 Aerodynamic coefficients for the 1903Flyer from −90 to 90 deg angle of attack.

of 30 deg. Note the match between the images part-for-part is not perfect due to the imperfect (but quiterepresentative) 3D model. This 30 deg deflection fromthe horizontal plane has led to the inclusion of the−30 to 30 deg data in the simulation model. (Basedon the results of this work and experience in flying themodel in the simulation, a deflection any higher than30 deg does not lead to more control power. In factthe 30 deg case is already highly stalled, but under-standably 30 deg canard deflection could result fromover control to avoid collision with the ground.)

In order to model high angle of attack excursions re-sulting from stalled flight, the data has been extendedover the range of −90 to 90 deg (see Fig.16) based onestimates and data taken from several sources. It isworth noting that at the extreme limits the drag coef-ficient does not reach a value of 2 due to the projectedarea of the biplane wing being roughly half that of thereference area, which for the 1903 Flyer is 510 ft2.

For the 1905 Flyer, a similar process was taken forgenerating the aerodynamic data for the simulation.Although the 1905 Flyer used the same wing biplanecell as the 1903 Flyer, the center of gravity moved1

and this obviously leads to differences in the longitu-

CMARC

Cm,sim

-10 0 10 20-0.5

-0.4

-0.3

-0.2

-0.1

0

w (deg)

Cm,w

α

Fig. 17 Pitching moment coefficient versus angleof attack for the main biplane wing of the 1905Flyer.

dinal aerodynamic data. Other substantial differencesderive from the larger canard and the reduced canarddeflection limits of ±15 deg reported in Ref. 14.

The lift characteristics used in the simulation arethe same as that shown in Fig. 11. Differences dueto the larger canard would affect these results, butthis relatively small effect is neglected in the currentmodel. The pitching moment shown in Fig. 17 differsprincipally from the center of gravity shift from 29.7%of chord as it is for the 1903 Flyer to 12.8% of chordfor the 1905 Flyer.1 The larger canard leads to con-siderably more control power as shown in Figs. 18 and19. Although the ±30 deg canard deflection data isshown, it is not used in the simulation in which thecanard deflection is limited to ±15 deg per the 1905blueprints. Figure 20 shows all of the data togetherover an angle of attack range of ±90 deg.

Other data contributing to the simulation includedlateral-directional stability and control data that wasestimated from the NASA Ames test data.15 Rudderpower effects and yaw data for the 1905 Flyer werescaled up from the 1903 Flyer measurements and re-duced to constant stability derivatives. Rotary deriva-tives (yaw and roll) have yet to be completely modeled,again due to emphasis being placed on longitudinalflying qualities. However, apparent mass effects inroll, pitch and plunge were calculated, and the resultsare mostly consistent with those reported in Ref. 18.

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CMARC

0

7.5

c = 30 deg

15

-7.5

-15

c = -30 degδ

δ

-10 0 10 20-1

-0.5

0

0.5

1

1.5

c (deg)

CL,c

Cn,c

α

Fig. 18 Lift coefficient versus angle of attack forthe 1905 canard at canard deflection angles rangingfrom −30 to 30 deg.

For reference, the wing warping deflection limits were±8.5 deg and for the 1903 Flyer the rudder deflectionwas coupled to the wing warping using the relationδr = 2.5∗δw. For the 1905 Flyer, no coupling was used,and in the simulation a rudder deflection of ±15 degwas found to be sufficient for coordinated flight.

Mass and moment of inertia data for the 1903 Flyerwere taken from Ref. 18. For the 1905 Flyer, momentof inertia data was estimated by subtracting off thecanard and rudder structure moment of inertia val-ues from the 1903 Flyer and then adding back thecanard and rudder structure moment of inertia val-ues for the 1905 Flyer. This approach gave estimatesthat were close to those estimated from a weight build-up approach. For the 1905 Flyer, the values used inthe simulation are as follows: Ixx = 1331, Iyy = 563,Izz = 1645 slug-ft2.

Finally, it should be mentioned that in a paper ofthis size there is insufficient space to include all of thesimulation data. However, all of the data and relatedsource code is available freely over the Internet at thewebsite www.flightgear.org. Updates to the data arelikely to occur as the simulation models evolve andbecome more refined when new information is found.

ResultsThe complete aerodynamic models for the 1903 and

1905 Wright Flyers were implemented in FlightGear

c = 30 degδ

15

7.5

0

-7.5

-15

c = -30 degδ

CMARC

-10 0 10 20-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

c (deg)

Cm,c

α

Fig. 19 Pitching moment coefficient versus angleof attack for the 1905 canard at canard deflectionangles ranging from −30 to 30 deg.

as was mentioned earlier. These models were flown todemonstrate the handling qualities of the two aircraft.The results of these flights are shown in Figs. 21– 25.Each of the figures are a plot of the time histories ofthe canard deflection, angle of attack, airspeed, pitchrate, pitch angle, and altitude. The altitude shown inthe plots is that of the center of gravity of the aircraft,so when the aircraft is on the ground, the altitude isnot zero.

Figure 21 shows the 1903 Flyer in a stall shortlyafter takeoff. The aircraft climbs to approximately20 ft while reaching the angle of attack reaches al-most 45 deg before nosing down and impacting theground. This flight and the flights shown in Figs. 22and 23 demonstrate the aircraft is very sensitive tocanard deflections and that the pilot has to contin-uously take action to keep the plane under control.The flight shown in Fig. 22 is of several short hopsperformed by the 1903 Flyer. The instability of this

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CL,w

CD

Cm,w

Cm,c

-90 -45 0 45 90-1

-0.5

0

0.5

1

1.5

(deg)α

Fig. 20 Aerodynamic coefficients for the 1905Flyer from −90 to 90 deg angle of attack.

aircraft leads to difficulty in keeping the aircraft in theair. It should be noted that the sudden jumps in datashown in Fig. 22 near 12 and 14 sec are due to theaircraft hitting the ground and the ground reactionmodel taking affect. Figure 23 shows a takeoff withthe 1903 Flyer, and demonstrates the constant controlaction required to keep the aircraft in the air. Evenwhen the aircraft is in the air as shown in Fig. 24, thepilot must still take continuous action. In the air the1903 Flyer is difficult to keep steady, and oscillationsin pitch and altitude are common. Figure 25 shows atakeoff and climbout for the 1905 Flyer. Even thoughthe aircraft has more pitch damping and is easier tocontrol, it still requires continuous corrections. Duringtakeoff the pilot must continuously adjust the canard,but once in the air, the amount of correction requiredis greatly reduced compared to the 1903 Flyer. Thesetime histories demonstrate the differences in the han-dling qualities of the two aircraft. While both requireconstant canard deflections to stay airborne (which il-lustrate the piloting skills of the Wright brothers), theamount and magnitude of the adjustments needed aresignificantly different.

SummaryIn order to expand the understanding of the han-

dling qualities of the 1903 and 1905 Wright Flyers,nonlinear aerodynamic models were created for eachaircraft and simulated with a flight simulator. Aero-dynamic data was generated by using wind tunnel testsof the 1903 Flyer and from inviscid flow analysis usinga panel method. The wing and canard for both air-craft were modeled separately to allow both elementsto stall independently of each other. The aerodynamicdata was extended from −90 to 90 deg angle of attackin order to model the nonlinear behavior of the aircraft

at high angles of attack. The resulting aerodynamicmodels were then implemented in the PC-based Flight-Gear Flight Simulator. Time histories of flights flownin the simulator demonstrate some of the differencesin handling qualities between the two aircraft. Bothaircraft require constant pilot attention, but the 1905Flyer requires much less than the earlier 1903 design.

AcknowledgmentsThe authors wish to acknowledge the FlightGear de-

velopment team for their development of the 3D visualmodels of the Wright Flyers, and in particular Lee El-liott for all of his work on the 1905 visual model. Thesemodels make flying the aircraft that much more enjoy-able.

References1Papachristodoulou, A.N. and Culick, F.E.C., “Flight Me-

chanics of the Wright Aircraft 1903–1912,” AIAA Paper 2003-0097, Reno, NV, Jan. 2003.

2FlightGear website, http://www.flightgear.org, 1997–present.

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4Dees, P., “How Gliders Helped the Wright Brothers Inventthe Airplane,” AIAA Paper 2003-0095, Reno, NV, Jan. 2003.

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6Culick, F.E.C., “The Wright Brothers: First AeronauticalEngineers and Test Pilots,” AIAA Journal , Vol. 41, No. 6, June2003, pp. 985–1006.

7Crouch, T.D., “The 1905 Wright Flyer: A Machine of Prac-tical Utility,” Timeline, Aug. 1985.

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9Ashby, D. L., Dudley, M. R., and Iguchi, S. K., “Develop-ment and Validation of an Advanced Low-Order Panel Method,”NASA TM 101024, October 1988.

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12Jackson, E.B., “Manual for a Workstation-Based GenericFlight Simulation Program (LaRCsim) Version 1.4,” NASA TM110164, April 1995.

13Blueprints of the 1903 Wright Flyer, Smithsonian NationalAir and Space Museum, Washington, DC.

14Blueprints of the 1905 Wright Flyer, Carillon HistoricalPark, Dayton, OH.

15Jex, H., Grimm, R., Latz, J.P., and Hange, C., “Full-Scale1903 Wright Flyer Wind Tunnel Test Results From the NASAAmes Research Center,” AIAA Paper 2000-0512, Reno, NV,Jan. 2000.

16Landman, D., Alvarez, J., Ash, R., Blackburn, S., andHyde, K., “Wind-Tunnel Testing of the Wright Brothers’ ModelB Airfoil,” Journal of Aircraft , Vol. 39, No. 1, Jan.-Feb. 2002,pp. 33–36.

17Knight, M. and Wenzinger, C.J., “Wind-tunnel tests on aseries of wing models through a large angle of attack range. PartI : force tests,” NACA Report 317, 1930.

18Jex, H.R. and Culick, F.E.C., “Flight Control Dynamics ofthe 1903 Wright Flyer,” AIAA Paper 85-1804-CP, 1985.

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16 16.5 17 17.5 18 18.5 19 19.5 20-30

-15

0

15

30

c (deg)δ

16 16.5 17 17.5 18 18.5 19 19.5 2020

30

40

50

V (ft/s)

16 16.5 17 17.5 18 18.5 19 19.5 20-1

-0.5

0

0.5

1

q (rad/s)

16 16.5 17 17.5 18 18.5 19 19.5 20-0.5

0

0.5

1

(rad)θ

16 16.5 17 17.5 18 18.5 19 19.5 200

10

20

30

time (s)

h (ft)

16 16.5 17 17.5 18 18.5 19 19.5 200

25

50

(deg)α

Fig. 21 Time history of the 1903 Flyer in a stall.

8 9 10 11 12 13 14 15 16 17 18-30

-15

0

15

30

c (deg)δ

8 9 10 11 12 13 14 15 16 17 18-15

0

15

(deg)α

8 9 10 11 12 13 14 15 16 17 1830

40

50

V (ft/s)

8 9 10 11 12 13 14 15 16 17 18-1

-0.5

0

0.5

1

q (rad/s)

8 9 10 11 12 13 14 15 16 17 18-0.5

0

0.5

(rad)θ

8 9 10 11 12 13 14 15 16 17 180

10

20

30

time (s)

h (ft)

Fig. 22 Time history of the 1903 Flyer performing some takeoff hops.

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40 41 42 43 44 45 46 47 48 49 50-1

-0.5

0

0.5

1

q (rad/s)

40 41 42 43 44 45 46 47 48 49 500

10

20

30

time (s)

h (ft)

40 41 42 43 44 45 46 47 48 49 50-0.5

0

0.5

(rad)θ

40 41 42 43 44 45 46 47 48 49 5030

40

50

V (ft/s)

40 41 42 43 44 45 46 47 48 49 50-15

0

15

(deg)α

40 41 42 43 44 45 46 47 48 49 50-30

-15

0

15

30

c (deg)δ

Fig. 23 Time history of the 1903 Flyer in a takeoff.

60 62 64 66 68 70 72 74 76 78 80-30

-15

0

15

30

c (deg)δ

60 62 64 66 68 70 72 74 76 78 80-15

0

15

(deg)α

60 62 64 66 68 70 72 74 76 78 8030

40

50

V (ft/s)

60 62 64 66 68 70 72 74 76 78 80-1

-0.5

0

0.5

1

q (rad/s)

60 62 64 66 68 70 72 74 76 78 80-0.5

0

0.5

(rad)θ

60 62 64 66 68 70 72 74 76 78 8020

30

40

50

time (s)

h (ft)

Fig. 24 Time history of the 1903 Flyer in the air.

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5 10 15 20 25 30 35-30

-15

0

15

30

c (deg)δ

5 10 15 20 25 30 35-15

0

15

(deg)α

5 10 15 20 25 30 3530

40

50

V (ft/s)

5 10 15 20 25 30 35-1

-0.5

0

0.5

1

q (rad/s)

5 10 15 20 25 30 350

20

40

time (s)

h (ft)

5 10 15 20 25 30 35-0.5

0

0.5

(rad)θ

Fig. 25 Time history of the 1905 Flyer in a takeoff and in the air.

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