The FAA has issued a safety alert for operators (SAFO) to explain the most recent changes to certification standards for the performance of slow flight and stall tasks in airplanes by private and commercial pilot applicants.
Both the June 2017 update of the airman certification standards (ACS) for private pilot-airplane applicants, and the first release of the Commercial Pilot-Airplane ACS, contain new elements based on feedback from the general aviation community.
When the Private Pilot-Airplane ACS debuted in June 2016, it included a revision of the evaluation of slow flight “to reflect maneuvering without a stall warning (e.g., aircraft buffet, stall horn, etc.).”
With the 2017 revision of the ACS, the FAA “refined and consolidated the risk management elements in the ACS,” and modified the phrasing of the slow flight skill element to require that an applicant “establish and maintain an airspeed at which any further increase in angle of attack, increase in load factor, or reduction in power, would result in a stall warning (e.g., aircraft buffet, stall horn, etc.).”
The SAFO offers a procedure for setting up the maneuver, involving slowing the airplane “to the stall warning in the desired configuration,” noting the speed, and then adjusting for a slightly higher airspeed to serve as the baseline speed for the demonstration.
To evaluate an applicant’s recognition of impending or full power-off and power-on stalls, the FAA added a requirement for the applicant to “acknowledge cues of the impending stall and then recover promptly after a full stall has occurred.”
The pilot could meet the requirement to acknowledge the cues “by simply stating ‘stall warning’ or ‘buffet,’” the SAFO says.
For commercial pilot-airplane practical tests, the FAA maintained the requirement that power-off and power-on stall recovery procedures “be executed at the first indication of an impending stall (e.g., buffet, stall horn, etc.).” However, the FAA modified the skill element to require the applicant to “acknowledge the cues and recover promptly at the first indication of an impending stall (e.g., aircraft buffet, stall horn, etc.).”
The FAA also noted in the SAFO that it decided to retain the accelerated stall task in the Commercial Pilot-Airplane ACS as a maneuver to be performed in single-engine and multiengine airplanes. The decision followed review of the comments from FAA flight test engineers who examined safety concerns raised by “members of the aviation community.”
The SAFO urged student pilots, flight instructor applicants, flight instructors, flight schools, Part 141 pilot schools, Part 142 training centers, and practical test evaluators to “adjust training and testing for the slow flight maneuver and stall tasks accordingly.”