As a result of this investigation, we made the following new urgent safety recommendations.
To Textron Aviation Inc.:
Define manufacturer-authorized pilot training and experience qualification criteria for pilots who perform postmaintenance stall test flights in Hawker 700, 800, 800XP, 850XP, and 900XP airplanes to ensure that they are prepared with the competencies needed to safely respond to an encounter with unacceptable stall characteristics. (A-26-1) (Urgent)
Develop a stall test plan that describes unacceptable stall characteristics, recovery procedures, and safety considerations needed to prepare manufacturer-authorized flight crewmembers to safely perform postmaintenance stall test flights in Hawker 750, 800, 800XP, 850XP, and 900XP airplanes. (A-26-2) (Urgent)
Review all other airplane models (besides the Hawker 750, 800, 800XP, 850XP, and 900XP) listed on type certificate A3EU, and, for each model that is subject to postmaintenance stall test flights, define stall test flight pilot training and experience qualification criteria and develop a stall test plan, as specified in Safety Recommendations A-26-1 and -2. (A-26-3) (Urgent)
Review the Pilot’s Operating Manual and Airplane Flight Manual for the airplanes on type certificate A3EU and revise them, as necessary, to provide a description of the adverse effects of certain wing surface anomalies, such as visually imperceptible defects or light ice accretion, on the airplane’s stall behavior, including:
- the possibility of stall before stick shaker or stick pusher activation;
- a description of unacceptable stall characteristics; and
- procedures for recovering the airplane from an inadvertent encounter with a stall and adverse stall behavior. (A-26-4) (Urgent)
Inform owners and operators of the airplane models on type certificate A3EU that are subject to postmaintenance stall flight tests of the circumstances of these accidents to increase their awareness of the possibility of unacceptable stall behavior, such as an uncommanded roll through 360° and entry into a spin, and that the flight crew training and experience needed to ensure the safety of these flights exceeds that which is typically provided to operational line pilots. (A-26-5) (Urgent)
To the Federal Aviation Administration:
Require Textron Aviation Inc. to complete the actions specified in Safety Recommendations A-26-1 through -3, and ensure that the information is accurate and correctly incorporated into the appropriate Federal Aviation Administration-approved manual or document for each airplane. (A-26-6) (Urgent)
To the National Business Aviation Association:
Inform your members about the recent accidents that occurred during postmaintenance stall flight tests required for certain Hawker airplanes, including the Hawker 750, 800, 800XP, 850XP, 900XP, and others on type certificate A3EU, to increase owner, operator, and pilot awareness that unacceptable stall behavior may occur and that the flight crew training and experience needed to ensure the safety of these flights exceeds that which is typically provided to operational line pilots. (A-26-7) (Urgent)
