Advises That 'Throttle Chops' Are Not Recommended In Training

The FAA has issues an SAIB for owners and operators of Schweizer 269C and 269C-1 aircraft. The document indicates that Schweizer has updated the instructions and warning in the approved Pilot Flight Manual (PFM) to avoid throttle chops to full idle, minimizing the possibility of engine stoppage.

The Windsor Locks Flight Standards District Office has found numerous NTSB accident reports involving practice autorotations of rotorcraft with air-aspirated engines. Most of these accidents were caused by pilots conducting a rapid movement of the throttle, i.e. throttle chop, resulting in the shutdown of the air-aspirated engine. Another major factor in the accidents is that the autorotations were practiced where by a safe touchdown could not be accomplished with an unplanned engine shutdown as is required by the FAA's Flight Instructor Practical Test Standards for Rotorcraft, Helicopter, Gyroplane (FAA-S-8081-7), and Commercial Pilot Practical test Standards for Rotorcraft, Helicopter, Gyroplane (FAA-S-8081-16). At this time, this airworthiness concern is not an unsafe condition that would warrant AD action under Title 14 of the Code of Federal Aviation Regulations (14 CFR) part 39.

The FAA strongly recommends that pilots and operators of rotorcraft with Schweizer 269C and 269C-1 follow the updated PFM revision #18 which was approved on June 28, 2011. The PFM was updated to clarify instructions for practice autorotations and to clarify warnings for pilots that "rapid throttle reductions to full idle shall not be conducted".

A Post Flight Requirements section also was added to the PFM to require the pilots to complete the following:

• Brief PAX on exit safety,
• Shutdown in accordance with Paragraph 4-14 & 4-16,
• Service aircraft as required,
• Notify maintenance of discrepancies, and
• Secure aircraft as required.

FMI: SAIB