THREE SURFACE AIRCRAFT

Chris ConradElizabeth CraigMatt Eluk

3/29/04

Components of a Three-Surface Aircraft (TSA)

Aft Tail

Wing

Lifting Canards

Strohmeyer, D., Seubert, R.. Improvement of a Preliminary Design and Optimization Program for the Evaluation of Future Aircraft Projects . AIAA-98-4828

Description

Simply put, this type of configuration adds canard surfaces to a conventional aft-mounted tail configuration.

Two categories:– Active Control (AFTI-15)

Also referred to as close-coupled canard TSA

– Stabilizer / Trim Surface (Avanti)

General Advantages

Additional lift in the nose region Simple high lift system and improved rotation

behavior Shorter take-off and landing paths Reduction of negative lift of horizontal tail

plane Larger payload at fixed wing size

General Disadvantages

Additional skin friction Higher aircraft weight (possible) Changed stability characteristics Changed aeroelastic characteristics

Examples of Three-Surface Aircraft

X-29--

Piaggio Avanti--

AFTI-15--

Chronology of TSA Development (Incomplete)

Curtiss-Herring No. 1 Reims Racer - 1908 De Havilland, Bi-plane No. 1 - 1909 Blohm und Voss BV P192 - 1942 Rutan Grizzly - 1982 Grumman X-29 and Piaggio P-180 - 1986

Aerodynamics

Pros High Lift

– Higher lift curve slope– ~5%-10% Higher CLmax

Stall– Pitch down during stall

Agnew, J.W., Hess, J.R., Jr. Benefits of Aerodynamic Integration to the Three Surface Configuration. AIAA-79-1830 August 1979

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Cruise– Can trim at min drag for

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Kendall, E.R.. The Aerodynamics of Three-Surface Airplanes. AIAA-84-2508

Aerodynamics

Cons Cruise drag

– Higher min drag– Lowest L/D

Selberg, B.P., and Rokhsaz, K.. Aerodynamic Tradeoff Study of Conventional, Canard, and Tri-Surface Aircraft Systems . AIAA-85-4071 October 1985

Stability and Control – Active Control

Integrated canard tends to move aerodynamic neutral point forward in aircraft, reducing the static margin.

Benefit for aircraft such as the AFTI-15 where increased maneuverability is desired

Agnew, J.W., Hess, J.R., Jr. Benefits of Aerodynamic Integration to the Three Surface Configuration. AIAA-79-1830 August 1979

Stability and Control – Active Control

Addition of close-coupled canard significantly increases efficiency of horizontal control surfaces, rudder surfaces, and ailerons

Can result in dramatic increase in pitch rate, roll rate, and yaw rate.

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Stability and Control – Active Control

Availability of direct side force through differential deflection of canards.

Adds entirely new degree of maneuvering freedom.

TSA provides a design with true six-degree-of-freedom maneuvering capability

Agnew, J.W., Hess, J.R., Jr. Benefits of Aerodynamic Integration to the Three Surface Configuration. AIAA-79-1830 August 1979

Stability and Control – Active Control

Availability of direct lift through symmetric deflection of canards.

Direct lift from deflection of canards is much more than that derived from extension of trailing-edge high-lift devices

Agnew, J.W., and Lyerla, G.W., and Grafton, S.B. The Linear and Non-Linear Aerodynamics of Three-Surface Aircraft Concepts. AIAA-80-1581 October/November 1984

Stability and Control – Trim / Stabilizer

“Three-surface airplanes can have minimum induced drag at all c.g. locations and be inherently stable.”

“Two-surface airplanes cannot have minimum induced drag at all c.g. locations.”

“Pure canard airplanes have much higher induced drag. Moreover, they cannot attain the minimum induced drag trimmed condition AND be inherently stable.”

-E.R. Kendall, Gates Learjet Corp. AIAA-84-2508

Trimmed stable condition occurs when canard and aft tail are loaded equally and in opposite directions

More of an aerodynamic consideration than stability

Structures

Reduced weight due to efficient structural integration

Increased weight from additional lifting surface

Piaggio Avanti

Composite materials Wing located farther back allows large cabin Wing torque box, aft pressure bulkhead, and

main gear share same fuselage bulkhead

Piaggio Avanti

X-29

Strake instead of aft tail Forward swept wings work well with canards

X-29

References

http://aarls.eng.ohio-state.edu/projects/avanti2.html Owens, D. Bruce & Coe, Paul L., Jr. Exploratory Wind Tunnel Investigation of the

Stability and Control Characteristics of a Three-Surface, Forward-Swept Wing Advanced Turboprop Model. AIAA-90-3074 August 1990

Kendall, E.R.. The Minimum Induced Drag, Longitudinal Trim and Static Longitudinal Stability of Two-Surface and Three-Surface Airplanes. AIAA-84-2164 August 1984

Agnew, J.W., and Lyerla, G.W., and Grafton, S.B. The Linear and Non-Linear Aerodynamics of Three-Surface Aircraft Concepts. AIAA-80-1581 October/November 1984

Kendall, E.R.. The Aerodynamics of Three-Surface Airplanes. AIAA-84-2508 Selberg, B.P., and Rokhsaz, K.. Aerodynamic Tradeoff Study of Conventional,

Canard, and Tri-Surface Aircraft Systems. AIAA-85-4071 October 1985 Strohmeyer, D., Seubert, R., Heinze, W., Osterheld, C., Fornasier, L. Three Surface

Aircraft – A Concept for Future Transport Aircraft. AIAA-00-0566 January 2000 Agnew, J.W., Hess, J.R., Jr. Benefits of Aerodynamic Integration to the Three

Surface Configuration. AIAA-79-1830 August 1979 Strohmeyer, D., Seubert, R.. Improvement of a Preliminary Design and Optimization

Program for the Evaluation of Future Aircraft Projects. AIAA-98-4828