Appendix 4 APPENDIX 4. SAMPLE FULL STALL TRAINING MANEUVER NOTE: Considerable evaluation of the FFS must occur before conducting full stall training in simulation. Reference Appendix 5 for all FFS evaluation considerations.
Training to full stall must be instructor led with a discussion of the learning objectives. Particular emphasis must be placed on the potential negative effects of training that traverses impending stall conditions to reach a full stall.
The goals of the training are (a) to provide the pilots the experience of the handling characteristics and dynamic cues (e.g., buffet, roll off) near and at full stall and (b) to reinforce the proper application of the stall recovery procedures.
Future full stall FFS models may contain a randomness feature that will allow a pilot to experience the in-flight variations in full stall characteristics. That is, no two real stalls are alike.
Performing this maneuver more than once, with perhaps instructor selection of stall response severity, could show a pilot both average and extreme response of a full stall.
This example is not intended to be limiting in any way, it is provided as a framework for developing a training curriculum.
NOTE: Reduction of AOA must be paramount in all stall prevention and recovery procedures. Operators should consult with their airplane manufacturer(s) to ensure they have the proper stall prevention and recovery procedure. Outdated procedures should be updated in accordance with this guidance.
SCENARIO: FULL STALL EXPERIENCE TRAINING
INSTRUCTOR ROLE Instructor-guided, pilot hands-on maneuver training.
OBJECTIVE Provide pilot(s) the experience of the airplane’s handling characteristics near and at full stall, the related cues, and full stall recovery.
EMPHASIS AREAS • Recognition and recovery.
• Crew coordination.
• AOA management.
• Out of trim control forces at autopilot disconnect (if engaged).
• Aural and visual warnings (environment and airplane cueing).
• Reduction of roll stability and increased buffeting.
• Effects of multiple levels of automation.
• Effects of altitude on recovery.
• SA while returning to desired flightpath after the stall, including such items as heading, terrain, altitude, other aircraft, and flight deck
Appendix 4 automation.
• There is no predetermined value for altitude loss. Maintaining altitude is not required.
FFS SETUP
CONSIDERATIONS
• This maneuver based training exercise must be conducted at an altitude that will allow for a recovery.
• Setup may be conducted on autoflight to allow for instructor-led discussion of expected cues and cautions (if feasible).
SCENARIO
ELEMENTS
• Create a situation which will result in a stall, such as reducing thrust to less than adequate to maintain airspeed and climb rate or adjusting flight path by varied means including changes to vertical rates, entering turn, etc., to yield an adverse energy trend.
• Upon pilot recognition of the impending stall, the instructor will encourage the further increase of AOA in order to reach full stall while highlighting the impending stall cues.
COMPLETION
STANDARDS
• The pilot will perform a deliberate and smooth reduction of AOA.
• Positive recovery from the full stall takes precedence over minimizing altitude loss.
• Appropriate application of thrust to accelerate and enable an expeditious recovery.
• The return of the airplane to safe flight without encountering a secondary stall.
• The maneuver is considered complete once the flight reaches and stabilizes at the assigned altitude.
• Satisfactory crew coordination must be demonstrated.
COMMON PILOT ERRORS
• Recovery is attempted with no loss of altitude.
• Recovery is attempted without recognizing the importance of pitch control and AOA.
• Rolling wings level prior to AOA reduction.
• Failure to roll wings level after AOA reduction to improve performance.
• Losing SA and failing to return to assigned flightpath or follow ATC instructions after recovery.
• Inappropriate use of rudder.
• Not disconnecting the autopilot and/or autothrottle/autothrust prior to reducing AOA.
Appendix 5 APPENDIX 5. FFS CONSIDERATIONS
1. SUMMARY OF SIMULATOR CAPABILITIES. Full Flight Simulators (FFS) that are appropriately qualified by the FAA can be used for stall prevention training as described below.
Full stall training and stick pusher demonstrations will require additional FFS evaluation. The current 14 CFR part 60 flight simulation training device (FSTD) qualification standards only include approaches to stalls as a minimum qualified task for FSTD levels A-D (see part 60 appendix A, table A1B, section number 3b). As a result, any FSTD being used to conduct full stall training tasks must be issued additional qualification to conduct these tasks as described in § 60.16. Training providers desiring to conduct full stall training as part of an FAA-approved flight training program are encouraged to review the National Simulator Program’s (NSP) guidance bulletin on evaluating an FFS for full stall training (FSTD Guidance Bulletin 14-01, FSTD Evaluation Guidelines for Full Stall Training Maneuvers) and the contents of this appendix before making a request for additional qualification. NSP guidance bulletins may be found on the FAA’s Web site at www.faa.gov.
A. Stall Prevention Training Maneuvers.
(1) To ensure a high level of FFS fidelity, stall prevention training maneuvers should be conducted in conditions similar to objectively evaluated test conditions where possible
(e.g., airplane weight, environmental conditions, stall entry rates, etc.). Current objective testing requirements for FFS qualification are for second segment climb and approach/landing conditions. The FSTDs Master Qualification Test Guide should be reviewed to assist in determining maneuvers that are likely to have a high level of fidelity. Since stall prevention training will typically take place well within an angle of attack (AOA) range in which the aerodynamic model has been objectively validated (and is a current FSTD qualification requirement in part 60 and previous grandfathered standards), it is not expected that significant modifications to the FSTDs will be required to conduct this training.
(2) For stall prevention training maneuvers that are not objectively evaluated for FFS qualification (such as cruise/high altitude impending stall and turning flight impending stall), the FSTD sponsor should conduct additional objective and subjective evaluation to determine adequate FFS fidelity. This additional evaluation should include:
(a) Objective evaluation of stall warning and stall buffet speeds against published airplane data (such as Airplane Flight Manual (AFM) stall tables).
(b) An assessment of the FSTD’s stall characteristics by a subject matter expert (SME) pilot with experience in the impending stall characteristics of the represented airplane.
B. Stall Recovery Training. For training to full stall, additional testing and validation of the specific FFS is necessary because of the variations among FFSs. While some FFSs may have the fidelity allowing training past impending stall conditions, the potential of negative transfer of training exists if simulated flight in this regime is not properly evaluated (through objective testing and evaluation by an SME pilot with experience in the stall characteristics of the airplane). FSTD evaluation recommendations to support additional FSTD qualification for full stall training tasks have been provided in an NSP guidance bulletin. The FAA is currently
Appendix 5 conducting rulemaking to codify FSTD evaluation requirements for full stall training tasks into part 60.
C. Stick Pusher Demonstrations. FFSs may be used to demonstrate the activation of a stick pusher system (if installed); however, training providers are cautioned that the airplane dynamics following a stick pusher activation may not accurately represent the airplane unless the FFS is properly modeled and evaluated. To ensure an adequate level of fidelity for stick pusher demonstrations, training providers should conduct additional testing and validation to ensure that the FFS’s stick pusher force complies with the design requirements specified by the manufacturer to ensure that it accurately represents the airplane, to include:
(1) The stick pusher activation speeds (or associated AOAs) should be objectively evaluated against published airplane data (such as the AFM stall tables).
(2) The modeling of the stick pusher system or stall protection system should be based upon airplane Original Equipment Manufacturer (OEM) provided simulation data or other suitable data to ensure correct activation speeds/AOAs and cancellation logic.
(3) The simulated stick pusher control forces and displacements should be validated against airplane collected or OEM provided validation data to ensure the FFS provides the correct control loading force cues.
(4) Since a stick pusher demonstration maneuver will typically occur at AOAs beyond the activation of the stall warning system, the FFS should be evaluated for satisfactory performance and handling qualities by an appropriately qualified SME pilot.
2. BACKGROUND INFORMATION. Currently, FSTD qualification standards are defined in 14 CFR part 60. Prior to part 60, FSTD qualification standards were defined in a series of advisory circulars (AC). During the development of this AC, current and historical FSTD qualification standards were examined to determine if adequate evaluation requirements were in place to conduct stall prevention and full stall training tasks in currently qualified FFSs. It was determined that previously qualified FFSs may not be capable of conducting training tasks to a full stall. The primary factors for this determination are as follows:
A. Until recently, flight training requirements were limited to impending stall maneuvers as opposed to full stall maneuvers. As a result, most current FFS stall training does not extend to AOAs much higher than that for an impending stall.
B. While much of the development of an FFS’s aerodynamic model at AOAs below the stall AOAs can assume a certain extent of linearity in extrapolating performance and handling characteristics, this assumption is not valid at, or past, full stall where the airplane dynamics and control characteristics may become nonlinear or unstable.
C. To fully evaluate the nonlinear characteristics of a stall model, more test points in the form of objective or subjective tests are necessary to validate such models.
Appendix 5 Page 3 (and 4)
3. PART 60 CHANGE. Through the collaborative efforts of various working groups and international committees, recommended modifications to the FSTD qualification requirements (as defined in the part 60 Qualification Performance Standards appendices) have been proposed.
These recommendations were formally presented to the FAA as part of the final report of the Section 208 Aviation Rulemaking Committee. The recommended changes to part 60 include improved objective and subjective FFS evaluation requirements for stall training tasks, upset recovery training tasks, and airborne icing simulation. The Flight Simulation Training Device Qualification Standards for Extended Envelope and Adverse Weather Event Training Tasks Notice of Proposed Rulemaking for part 60 was published in July 2014. The publication of a final rule establishing the FFS qualification standards for full stall is projected to be early 2016, which is prior to the March 12, 2019 compliance date for full stall training for part 121 pilots.
Advisory Circular Feedback Form If you find an error in this AC, have recommendations for improving it, or have suggestions for new items/subjects to be added, you may let us know by contacting the Air Transportation Division (AFS-200) or the Flight Standards Directives Management Officer.
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