1. THREE SURFACE AIRCRAFT
Chris Conrad
Elizabeth Craig
Matt Eluk
3/29/04

2. 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

3. 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)

4. 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

5. General Disadvantages
Additional skin friction
Higher aircraft weight (possible)
Changed stability characteristics
Changed aeroelastic characteristics

6. Examples of Three-Surface Aircraft
Piaggio Avanti--
AFTI-15--

7. Chronology of TSA Development (Incomplete)
Curtiss-Herring No. 1 Reims Racer
De Havilland, Bi-plane No
Blohm und Voss BV P
Rutan Grizzly
Grumman X-29 and Piaggio P

8. Aerodynamics Pros High Lift Stall 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 August 1979

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

10. Aerodynamics Cruise Can trim at min drag for any CG
Kendall, E.R.. The Aerodynamics of Three-Surface Airplanes. AIAA

11. 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 October 1985

12. 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 August 1979

13. 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.
AFTI-15

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

15. 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 August 1979

16. 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 October/November 1984

17. 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
Trimmed stable condition occurs when canard and aft tail are loaded equally and in opposite directions
More of an aerodynamic consideration than stability

18. Structures Reduced weight due to efficient structural integration
Increased weight from additional lifting surface

19. Piaggio Avanti Composite materials
Wing located farther back allows large cabin
Wing torque box, aft pressure bulkhead, and main gear share same fuselage bulkhead

20. Piaggio Avanti

21. X-29 Strake instead of aft tail
Forward swept wings work well with canards

22. X-29

23. 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 August 1990
Kendall, E.R.. The Minimum Induced Drag, Longitudinal Trim and Static Longitudinal Stability of Two-Surface and Three-Surface Airplanes. AIAA 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 October/November 1984
Kendall, E.R.. The Aerodynamics of Three-Surface Airplanes. AIAA
Selberg, B.P., and Rokhsaz, K.. Aerodynamic Tradeoff Study of Conventional, Canard, and Tri-Surface Aircraft Systems. AIAA October 1985
Strohmeyer, D., Seubert, R., Heinze, W., Osterheld, C., Fornasier, L. Three Surface Aircraft – A Concept for Future Transport Aircraft. AIAA January 2000
Agnew, J.W., Hess, J.R., Jr. Benefits of Aerodynamic Integration to the Three Surface Configuration. AIAA August 1979
Strohmeyer, D., Seubert, R.. Improvement of a Preliminary Design and Optimization Program for the Evaluation of Future Aircraft Projects. AIAA