Clean Configuration Stall Prevention

Two things. First, the entry is while in cruise flight — there is no configuration to establish, so the skill element only requires coordinated flight in simulated or actual instrument conditions throughout (AA.V.B.S3). Second, the recovery ends simply with return to the desired flight path as specified by the evaluator (AA.V.B.S7) — there is no flap or gear retraction step, because there is nothing extended. The added knowledge element is the one that matters: effects of altitude on performance (e.g., thrust available) and flight control effectiveness during a recovery (AA.V.B.K6).

• Entry altitude allowing the recovery to be completed no lower than 3,000 feet AGL (non-transport category) or 5,000 feet AGL (transport category), after clearing the area (AA.V.B.S1)
• Bank angle 15°–30°, with pitch and power adjusted smoothly per the evaluator's instructions to an impending stall (AA.V.B.S4)
• Coordinated flight in simulated or actual instrument conditions throughout (AA.V.B.S3)
• Recovery promptly at the first indication of an impending stall, with the cue(s) acknowledged (AA.V.B.S5)

Same numbers as the partial flap and landing Tasks. There is still no altitude-loss, airspeed, or heading tolerance.

Weight, G loading, CG, bank angle, altitude, and icing all move it — AC 120-109 names exactly this list of factors affecting handling characteristics and stall speed (para 4-2b). AA.V.B.K1 tests the same relationship: AOA, airspeed, load factor, power setting, aircraft weight and balance, and attitude. Start from the AFH's warning that a published level-flight 1G stall speed is valid only:

1. In unaccelerated 1G flight
2. In coordinated flight (slip-skid indicator centered)
3. At one weight (typically maximum gross)
4. At one CG (typically maximum forward)

Break any of those four and the number on the page is optimistic. For a clean, uncontaminated wing the critical AOA does not move — only the speed at which you reach it does. (Icing is the exception: contamination changes the critical AOA itself — see the cruise-scenarios card.)

Stalling speed increases at the square root of the load factor (AFH ch. 10; AC 61-67 states the same rule). The Task is flown at 15°–30° (AA.V.B.S4), so the penalty is modest — but it stacks on top of weight and altitude. The AFH and AC 61-67 give matching examples:

• Level flight: stalls at 50 knots
• 45° bank: stalls at 60 knots
• 60° bank: stalls at 70 knots
• 4 G load factor: a 45-knot airplane stalls at 90 knots — an accelerated maneuver stall, so named because it arrives at a higher indicated airspeed than any stall you practiced

Two consequences for the check:

• As bank steepens, the margin between stalling speed and maneuvering speed decreases (AFH ch. 10). An accelerated stall — one of the risk items in AA.V.B.R5 — is simply reaching the critical AOA at a higher-than-normal airspeed, so the cues arrive sooner than your airspeed instinct expects.
• Weight and CG shift it too: forward CG gives a slightly higher stalling speed but favorable stall characteristics; aft CG gives a slightly lower stalling speed and less desirable stall characteristics (AFH ch. 13).

The simulator can also mask this: AC 120-109 lists G loading awareness / accelerated stall among the FFS limitations instructors must brief, since those cues can be absent from the device (para 2-4).

AC 120-109: at high altitudes, stall recovery will likely require losing several thousand feet. The AFH agrees — at high altitude, where available thrust is significantly less than at lower altitudes, recovery may require significant pitch down to regain airspeed, and several thousand feet or more of altitude loss may occur (AFH ch. 16). This is why there is no altitude-loss criterion in the ACS, and why an applicant who tries to fly a high-altitude recovery like a low-altitude one usually earns a secondary stall warning. Note that the warning itself is not the bust: AC 120-109 says a secondary stall warning is acceptable as long as AOA is promptly reduced and the airplane's limitations are not exceeded (para 4-2a). What fails you is chasing the altimeter instead of the AOA.

No. AC 120-109 is explicit: declare an emergency if necessary — do not delay recovery due to degrading airspeed or a stall event to obtain ATC clearance to a lower altitude (para 4-2). The altitude is yours to trade, and the coordination happens afterward. The pilot monitoring handles the declaration and the deviation call while the pilot flying flies the recovery.

Because the aerodynamics are the same: reducing AOA eliminates the stall regardless of altitude. The AFH says the high-altitude technique is the same — lower the nose until the stall warning stops — but adds that after the AOA is reduced to where the wing is again developing efficient lift, the airplane will still likely need to accelerate to a desired airspeed (AFH ch. 16). What changes is not the procedure but the energy budget: down low there is thrust to stop the descent quickly; up high there is not, so the altitude does the work the thrust cannot.

Two effects, and AC 120-109 names both under altitude effects: thrust available for recovery is reduced, and there is a lack of airflow through the engines at high AOA. The AC draws the conclusion for you — this reinforces that reduction of AOA must precede any increase of thrust (para 4-2). Adding thrust into a high-AOA, high-altitude condition may buy you very little and can cost you a compressor stall or an unhelpful pitch couple.

AC 120-109 lists pitch rate sensitivity of flight controls due to lack of aerodynamic damping among the differences between high and low altitude stalls (para 4-2). Thin air means less damping in pitch and roll, so a given control input produces a larger and faster response than the same input produces at low altitude. Practically: your nose-down input needs to be positive but smooth, and the recapture of the flight path needs to be gentle — the AC's rationale for step 6 is to apply gentle action for recovery to avoid secondary stalls.

AA.V.B.K3 and R1 ask for exactly this. Realistic ones:

• Loss of reliable airspeed — blocked or iced pitot inputs feeding both the pilots and the autoflight
• An autopilot holding altitude while drag rises or thrust falls, trimming nose-up as speed decays
• Turbulence, mountain wave, or a temperature shear at an altitude with a thin maneuver margin (AA.V.B.R6)
• An inadvertent climb above the airplane's capability for the weight and temperature
• Icing changing the wing's critical AOA, so the stall arrives at a speed and attitude that look normal
• Distraction and task saturation, plus loss of situational awareness or disorientation (AA.V.B.R8)

Because the low-speed and high-speed buffet boundaries converge as altitude increases; the point where they merge is the aerodynamic ceiling, known as coffin corner. At cruise altitude you are boxed in from both sides: slowing brings you to the low-speed buffet boundary, where prestall buffet begins, and accelerating brings Mach buffet — airflow separation behind a shock wave (AC 61-107). Increasing weight or G loading raises the low-speed buffet speed and lowers the Mach buffet speed — AC 61-107's example turbojet at 51,000 feet meets buffet at only 1.4 G, so a bank, a gust, or a speed change can erase the margin. This is why AC 120-109 lists Mach effects among the factors leading to a stall event and expects knowledge of your buffet boundary and margins — including the different buffet cues on the high-speed versus low-speed side (paras 3-2b, 3-2d). Select a cruise altitude that leaves sufficient buffet margin for the maneuvering and gusts expected (AC 61-107).

Turbulence can cause an aircraft to stall at a significantly higher airspeed than in stable conditions — a vertical gust or windshear produces a sudden change in the relative wind and an abrupt increase in AOA (AC 61-67). Even a gust too brief to develop a stall by itself can stall the airplane while you are correcting the flightpath. The speed guidance (AC 61-67, para 100):

• In moderate or severe turbulence in cruise, fly an airspeed well above the indicated stall speed and below maneuvering speed (VA)
• Remember VA is lower at a lower weight
• Respect what VA does not protect: do not use full or abrupt control movements at or above VA — and rapid, large alternating control inputs, especially combined with large changes in pitch, roll, or yaw, can produce structural failure at any speed, even below VA

This is the mechanism behind the turbulence item in AA.V.B.R6: the margin problem is an AOA problem before it is an airspeed problem.

Per AC 120-109, para 4-5:

• Prompt recognition of the impending stall
• Correct application of the stall recovery procedure
• Recovering without exceeding the airplane's limitations

The AC adds that the check pilot establishes the flight conditions and that you may fly the entry profile but are not being checked on the entry — except for recognition of the deteriorating flight situation (para 4-4). You are graded from the cue forward, plus whether you saw it coming.

The one set forth in the POH/Flight Manual for the airplane (AA.V.B.S6). AC 120-109 defines the stall recovery procedure as the correct, airplane-specific actions developed by the operator in consultation with the airplane manufacturer; only if consultation is impracticable does the stall recovery template in Appendix 1 apply. Know your operator's procedure verbatim, and know that it maps onto the template:

1. Disconnect the autoflight
2. Reduce AOA
3. Roll wings level
4. Manage thrust
5. Retract speed brakes
6. Return to the flightpath

The boundary layer on a swept wing tends to flow spanwise toward the tips, and the tendency for tip stall — allowing the center of lift to move forward — is greatest when wing sweep and taper are combined (AFH ch. 16). A forward shift in the center of lift is a nose-up pitching moment at exactly the wrong moment. Manufacturers fight it by modifying the wing spanwise with twist, changes in airfoil section, vortex generators, or a combination, which helps you retain roll control initially if a stall is entered inadvertently. Note the consequence for cues: airplanes without vortex generators may stall with little to no buffet (AFH ch. 16).

Some T-tail configurations are prone to deep stalls, where the tail becomes immersed in the wing wake at very high angles of attack and loses effectiveness, often with a high rate of descent (AFH ch. 16). It feels wrong because high angles of attack can occur at any pitch attitude — even with the nose below the horizon — so the correct action is to push the nose down even further. The AFH warning: deep stalls may be unrecoverable, but they are easily avoided as long as published limitations are observed. On susceptible types, stick shakers are standard equipment and a stick pusher may be fitted.

A stick pusher applies an abrupt and large forward force on the control column (AFH glossary) to automatically reduce the airplane's AOA before the airplane reaches a dangerous stall condition, or to aid recovery where the airplane's natural aerodynamic characteristics do so weakly (AFH ch. 16). Two conclusions. First, pusher activation is an indication of a full stall (AC 120-109 definition; AFH ch. 5) — if it fires on the check, the impending stall was not prevented. Second, avoid situations that would activate a stick pusher when close to the ground (AFH ch. 16). Under 121.423(c), full stall and stick pusher activation recovery is instructor-guided training in a Level C or higher FFS, not a check maneuver.

The AFH states the training standard directly: pilots undergoing training in jet airplanes are taught to recover at the first indication of an impending stall instead of going beyond those initial cues and into a full stall — normally indicated by aural stall warning devices, annunciators, or activation of the stick shaker. The proper action is a nose-down input until the stall warning stops (pitch trim may be necessary), then roll wings level, then adjust thrust to return to normal flight (AFH ch. 16). The AFH also frames the division of labor cleanly: reducing AOA eliminates the stall, but added thrust allows the descent to be stopped once the wing is flying again.

By doing exactly what it was told. An autopilot holding an altitude or a vertical path will trim nose-up as speed decays, quietly consuming your maneuver margin, and AC 120-109 notes that reducing AOA in the recovery also addresses autopilot-induced excessive nose-up trim (Appendix 1 rationale, step 2a). When it can hold no longer, the abrupt pitch-up or trim change at an unexpected autopilot disconnect hands you a physical problem on top of an aerodynamic one, and in some airplanes an additional pitch-up when thrust is increased (para 4-2). AA.V.B.K4 asks about envelope protection in normal and degraded modes — answer for your type from the AFM and FSB report, never generically.

AC 120-109 defines startle as an uncontrollable, automatic muscle reflex, raised heart rate, blood pressure, etc., elicited by exposure to a sudden, intense event that violates a pilot's expectations — and identifies surprise as a factor in stall incidents and accidents. The AC therefore encourages using surprise in training, to reinforce timely application of the recovery under confusing circumstances, while stating that surprise should not be used during checking (definition at para 1-7p; the training guidance is para 4-3, "Using Surprise in Training"). It also notes the practical confusion source: noises associated with stick shakers, autopilot, and autothrottle/autothrust disconnect alarms can cause confusion in the cockpit (para 4-2). This is why the procedure is memorized in an order — startle is survived by sequence, not by improvisation.

AC 120-109 defines maneuver-based training as training that focuses on a single event or maneuver in isolation, and scenario-based training (SBT) as training that incorporates maneuvers into real-world experiences to build practical skills in an operational environment. SBT normally comes after you demonstrate proficiency in maneuver-based training, during upgrade and recurrent training, and its scenarios should draw on accident, incident, ASAP, FOQA, and ASRS data. Pilots are not normally briefed that they are receiving SBT — and if you recognize and prevent the stall before the scenario fully unfolds, that is the desired objective (para 4-2). Area V is the maneuver-based half; the line-oriented half is where the prevention skill is actually proven.