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Lecture 7: Stability & Control. Jason Mickey For AE 440 A/C Lecture September 2009. S&C Responsibilities. Select/design/size all control surfaces, e.g. horizontal tail, vertical tail, etc. (sizes to aerodynamics & configuration Determine/Ensure static margin range for all flight conditions
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Lecture 7: Stability & Control Jason Mickey For AE 440 A/C Lecture September 2009
S&C Responsibilities • Select/design/size all control surfaces, e.g. horizontal tail, vertical tail, etc. (sizes to aerodynamics & configuration • Determine/Ensure static margin range for all flight conditions • Evaluate longitudinal and lateral stability (suggest needed changes to configuration) • Specify avionics and any digital control system (weight/size to internal configuration) • Evaluate dynamic stability (phugoid & short period) and evaluate flying qualities (e.g. with a flight simulator)
Control Surface Sizing • Horizontal tail, elevator • Vertical tail, rudder • Ailerons
Longitudinal Moments Raymer, Fig. 16.3
Types of Tails Raymer, Fig. 4.30
Tail and Control Surface Sizing (Raymer)
Neutral Point Find such that for all a (Raymer)
Elevator to Trim Find such that Raymer, Fig. 16.18
Stability and Handling Qualities • Static stability • Dynamic stability • Handling qualities
Suggestions for CR • Determine tail-type(s) • Finish sizing tail and control surfaces • Determine elevator reqt. for takeoff & landing • Determine trim points • Determine static margin range • Investigate static stability • Trade studies, e.g. tail size/location vs. trim elevator deflection