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Recommendation issued to: Federal Aviation Administration (FAA)

Recommendation details
Output No: R20000009
Date issued: 07 January 2000
Safety action status:
Background: Why this Recommendation was developed

Output text

The Australian Transport Safety Bureau (formerly the Bureau of Air Safety Investigation) recommends that the US Federal Aviation Administration review Rolls Royce RB211-524D4 engine cold stream nozzle inspection criteria to minimise the possibility of failure during operation.

Initial response
Date issued: 08 August 2000
Response from: Federal Aviation Administration (FAA)
Action status: Closed - Accepted
Response text:

This memo is in response to Federal Aviation Administration (FAA) Safety Recommendations 00.010 and 00.011. The recommended action is to prevent conditions that caused an uncontained cold stream nozzle failure in a Rolls-Royce plc RB211-524D4 engine model. Cold stream nozzle failure is attributed to cracking and delamination of the acoustic liner at the top right side of the cold stream nozzles resulting in departure of nozzle sections from the engine. The failure resulted in sections of the cold stream nozzle departing the engine and impacting a number of the aircraft wing leading edge panels and the number 1 flap fairing.

Recommendation 00.011: The Australian Transport Safety Bureau (formerly the Bureau of Air Safety Investigation) recommends that "the U.S. Federal Aviation Administration review Rolls Royce RB211-524D4 engine cold stream nozzle inspection criteria to minimize the possibility of failure during operation."

ECO Response: The FAA agrees with Recommendation 00.011. The United Kingdom Civil Aviation Authority (CAA) recently notified the ECO concerning a recent event in which an RB211-524D4 powered Boeing 747 suffered the loss of a section of cold stream nozzle in flight. As a result of the cold stream nozzle failure, the CAA has issued Airworthiness Directive (AD), 005-01-2000 in conjunction with Rolls-Royce plc (RR) Mandatory Service Bulletin RB.211-78-C955. The AD requires borescope inspection of the cold stream nozzle longitudinal flange forward and aft of the forward Z-section circumferential stiffener position for cracks. AD mandatory inspection compliance requirements are specified as no later than 400 flight hours or 100 flight cycles, whichever is the sooner, from the issue date of the Mandatory Service Bulletin, which is dated January 31, 2000.

The ECO is currently reviewing the available data concerning cold stream nozzle failures. The FAA will issue an AD in accordance with the requirements of the CAA AD. The Engine and Propeller Directorate will forward the AD to AAI when it is issued.

 
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Last update 05 April 2012