Aviation safety issues and actions
Recommendation issued to: United States Federal Aviation Administration
|Date issued:||07 July 2006|
|Safety action status:||Closed - No Action|
|Background:||Why this Recommendation was developed|
The Australian Transport Safety Bureau recommends that the United States Federal Aviation Administration consider revising Title 14 Code of the Federal Regulations, Part 23.1155, to require a positive means to prevent operation of the propeller in the beta mode while in flight (regardless of pilot action), unless the aircraft is certified for such use.
|Date issued:||10 January 2007|
|Response from:||United States Federal Aviation Administration|
|Action status:||Closed - Not Accepted|
The FAA has reviewed its current regulations and policies, and decided to not adopt the specific recommendation. A copy of the analysis accomplished by the FAA Small Airplane Directorate is enclosed for your information.
14 CFR, part 23, §23.1155 states:
The National Transportation Safety Board (NTSB) issued a safety recommendation, A-94-62, dated March 2,1994, to revise 14 CFR, part 23, 23.1155 to require beta lock-out systems on small airplanes to prevent operation of the propeller beta mode while in flight. The National Transportation Safety Board cited similar instances on different aircraft over the last 12 years supporting the safety recommendation requiring an in-flight beta lock-out system. The FAA stated its response to the NTSB in a letter dated March 20, 2001:
The FAA reiterated its March 20, 2001 response to the NTSB in a letter dated October 22, 2001:
The addition of a beta lock-out system requires increased system complexity:
Some of the associated failure modes of a beta lock-out system include:
The Australian Transportation Safety Board (ATSB) Aviation Occurrence Report - 200404589 Final, cites the in-flight usage of beta in a Fairchild Industries SA227-AC Metro III aircraft as an example supporting the safety recommendation. The FAA issued an Airworthiness Directive (AD 92-18-07) on October 2, 1992 specifically addressing the flight idle detent functionality for the Fairchild Aircraft (formerly Swearingen Aircraft Corporation) SA226-T, SA226- T(B), SA226-AT, SA226-TC, SA227-TT, SA227-AT, SA227-AC and SA227-BC Airplanes.
The specifics of the occurrence cited in the ATSB report clearly
point to a situation in which the Airplane Flight Manual (AFM)
procedures were not followed. There was a separate and distinct
operation by the crew to place the power lever in the beta range,
when the AFM specifically states that propeller reversing in flight