Pilots donât need aerodynamics at the level of Greek Letters and many decimal places to be safe in flight. But understanding the basic physics of flight is essential. F-16 pilot and good friend AF General Mike Hall calls this âfighter pilot math;â a practical working knowledge ready for immediate use. Remember, gravity works tirelessly, day and night all year long. We are continuously using physical forces to safely stay aloft.
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BTW: I am only a pilot CFI/DPE so I checked my answers with a much more qualified guy; Ron Blum. He supervised/created Flight Test and Aerodynamics departments at Cessna, Honda, Beech & Kestrel before being Chief Engineer for Mooneyâs M10. I learned a lot talking with Ron!
1) Misunderstood Angle of Attack
These two photos depict a C-152 in climb and descent. Photo A shows a Vy climb in the âcleanâ configuration. Photo B shows a reduced power (pattern) descent with flaps deployed (same plane, same loading). Both have approximately the same angle of attack (notice the same airspeed of 60K). Why does this matter? Pilots seem to universally fear the nose high flight attitude and often do not pitch enough for maximum performance when they need to (timid pilot). Additionally, many pilots mistakenly believe a nose-low attitude guarantees safety, when in fact this aircraft is just as close to a stall as the nose-high aircraft. Pilots practice âpredictable stallsâ in training and are not ready for âsurprise stallsâ encountered in an upset.
Flaps deployed dramatically change the wing
2) Where is the CG (and why does this matter)?
3)Lift is Equal on the Wings in a Stabilized Turn
In a stabilized turn, lift is equal on the wings (or your plane would still be rolling). In a 30-degree banked turn, trim the nose for hands-off level flight and fold your arms. A well-rigged plane will continue to turn happily with no input until you run out of fuel. (this is a great CFI demonstration for early learners to dissipate their fear of turns)
Why is this important? If pilots fear turning and stalls they become timid pilots, skidding their plane instead of banking. (I would guess ~50% of PPL test applicants have never done a turning stall). The nose simply falls away from the lift vector and the real takeaway is that there is usually even fewer real aerodynamic signals (no âbreakâ). Most trainers simply start to mush and their pilots fail to realize they are even stalled!
4) The âActive Controlâ in a turn is the elevator.
See the above demonstration of trimming a stable turn, ailerons and rudder should be neutral in a medium-banked turn in a well-rigged aircraft. The elevator is turning the plane. Rolling into and out of a turn obviously requires the coordinated use of ailerons and rudder (and differential lift). Turning with just the rudder is a skidâŚnot conducive to long life and health.
5) No Spin From a Coordinated Turning Stall.
See #3 above, but âstall breakâ in most planes is even less pronounced than level. The aircraft nose falls away from the lift vector (nose to toes). Most planes have built-in dihedral stability so many planes roll out of the turn. (No âexcitementâ if you are coordinated â the âbig if!â). A demonstration of a stall in a slip or skid is useful for advanced pilots (try this only with a CFI please â required on the CFI initial). Pro tip: Most trainers just mush in a power-off slip when brought to a stall; yaw and roll balance out nicely.
6) Stall speed only increases by 19% in a 45-degree banked turn!
Maintaining 1.4 Vso in the pattern actually provides a 20% margin over stall even in with a 45-degree bank (just sayin, not
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