AP.IV.E.K3
KnowledgeFactors and situations that can lead to a stall during flight and actions that can be taken to prevent it.
From the FAA library
- Chapter 5: Aerodynamics of Flight › Load Factors › Load Factors and Stalling Speeds
Load Factors and Stalling Speeds Any aircraft, within the limits of its structure, may be stalled at any airspeed. When a sufficiently high AOA is imposed, the smooth flow of air over an airfoil breaks up and separates, producing ... abrupt change of flight characteristics and a sudden loss of lift, which results in a stall. A study of this effect has revealed that an aircraft’s stalling speed increases in proportion to the square root of the load factor…
- Chapter 5: Aerodynamics of Flight › Load Factors › Stalls
Stalls The normal stall entered from straight-and-level flight, or an unaccelerated straight climb, does not produce added load factors beyond the 1 G of straight-and-level flight. As the stall occurs, however, this load factor ... reduced toward zero, the factor at which nothing seems to have weight. The pilot experiences a sensation of “floating free in space.” If recovery is effected by snapping the elevator control forward, negative load factors (or those that impose…
- Chapter 5: Aerodynamics of Flight › Stalls
stated above, it does not completely stop producing lift. In most straight-wing aircraft, the wing is designed to stall the wing root first. The wing root reaches its critical AOA first making the stall progress outward toward the wingtip ... having the wing root stall first, aileron effectiveness is maintained at the wingtips, maintaining controllability of the aircraft. Various design methods are used to achieve the stalling of the wing root first. In one design, the wing is “twisted…
- Chapter 5: Aerodynamics of Flight › Boundary Layer Separation › Sweepback
words, the use of sweepback “softens” the force divergence. A disadvantage of swept wings is that they tend to stall at the wingtips rather than at the wing roots. [Figure 5-69] This is because the boundary layer tends ... flow spanwise toward the tips and to separate near the leading edges. Because the tips of a swept wing are on the aft part of the wing (behind the CL), a wingtip stall causes the CL to move forward…
- Chapter 5: Maintaining Aircraft Control: Upset Prevention and Recovery Training › Stalls › Stall Recognition
Indications of a full stall are typically that an uncommanded nose down pitch cannot be readily arrested, and may be accompanied by an uncommanded rolling motion. For airplanes equipped with stick pushers, their activation is also an indicator ... full stall. Although it depends on the degree to which a stall has progressed, some loss of altitude is expected during recovery. The longer it takes for the pilot to recognize an impending stall, the more likely it is that…
- Chapter 5: Maintaining Aircraft Control: Upset Prevention and Recovery Training › Stalls › Accelerated Stalls
Accelerated Stalls While pilots may understand the cause of an accelerated stall, it takes training to experience how these stalls develop and occur. The objectives of demonstrating an accelerated stall are to determine the stall characteristics of the airplane, experience ... stalls at speeds greater than the +1G stall speed, and develop the ability to instinctively recover at the onset of such stalls. This is a maneuver only commercial pilot and flight instructor applicants may be required to perform…