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Safety Recommendation Details

Safety Recommendation A-08-082
Details
Synopsis: On August 4, 2008, about 0545 eastern daylight time, a Bombardier CL-600-2B19, N422AW, operated as US Airways flight 4099, lost part of its right engine upper fan cowl while in flight at approximately 11,000 feet. The flight continued to its intended destination and landed without further incident at Charlotte Douglas International Airport, Charlotte, North Carolina, about 0630. The pilot, copilot, flight attendant, and 50 passengers on board were not injured; the airplane sustained minor damage, including damage to the left and right horizontal stabilizer and the fuselage. The airplane was operated under the provisions of 14 Code of Federal Regulations (CFR) Part 121 as a scheduled domestic passenger flight. Visual meteorological conditions (VMC) prevailed, and an instrument flight rules (IFR) flight plan was filed.
Recommendation: TO THE FEDERAL AVIATION ADMINISTRATION: Determine the extent of the problem of engine fan cowl separations on all airplanes and, should a widespread problem exist for any airplanes, require operators of those airplanes to include a dual inspection signoff in their maintenance procedures to confirm that engine fan cowls are latched after completing any engine maintenance that involves the opening of an engine fan cowl.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Aviation
Location: Charlotte, NC, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: ENG08SA037
Accident Reports:
Report #: None
Accident Date: 8/4/2008
Issue Date: 10/10/2008
Date Closed: 10/28/2011
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s): Engine, Maintenance, Records

Safety Recommendation History
From: NTSB
To: FAA
Date: 10/28/2011
Response: The NTSB notes that the FAA reviewed several databases containing data from 2000 through 2010 to determine the extent of the engine fan cowl separation problem and determined that the problems exist primarily with the Airbus SA A-319-132 and Bombardier CL-600-2B19 airplanes. The FAA further stated that it had found no records indicating engine fan cowl separation incidents due to improper latching since August 2008. This recommendation was issued to determine whether engine fan cowl separation problems had occurred on aircraft other than the Airbus SA A-319-132 and Bombardier CL-600-2B19 and, if similar problems were found, to prompt the FAA to take actions similar to those in Safety Recommendation A-08-79 to -81 for these two airplane models. With the completion of the FAA’s review and its determination that no other model airplanes have similar problems, the FAA has satisfied Safety Recommendation A-08-82, which is classified CLOSED—ACCEPTABLE ACTION.

From: FAA
To: NTSB
Date: 8/2/2011
Response: CC# 201100308: - From J. Randolph Babbitt, Administrator: The FAA reviewed several databases with data from 2000 through 20 I0 to determine the extent of the engine-fan cowl separation problem. Our original assertion that all aircraft models were affected was incorrect. Statistics do not indicate that a widespread problem exists in the industry. The review of incidents found in SDRs, Accident Incident Database System, Aviation Safety Information Analysis and Sharing System, and Safety Performance Analysis System consist primarily of the Airbus SA A-319-132 and Bombardier CL-600-2B19 model airplanes, as indicated in the Board's letter dated October 10, 2008. We continue to review various databases and have found no records indicating engine-fan cowl separation incidents due to improper latching since August 2008. Airbus reviewed the design of engine-fan cowl latches on certain A319, 320 and 321 aircraft and developed modifications that the FAA mandated by Airworthiness Directive 2003-18-06, Airbus (enclosure 3). While these modifications cannot prevent improper or incomplete latching of the engine-fan cowl, the modifications, recommended training programs, and recommended dual signatures in the aircraft log serve to mitigate the problem. Additionally, Bombardier reviewed their designs and maintenance manuals and determined that it was appropriate to include cautions to make sure that all fasteners are installed and a recommendation that operators utilize a dual sign-off procedure for nose access cowls. They included this in their Nose Access Cowls-Removal/Installation (enclosure 4) maintenance manual change on May 29, 2008. I believe that the FAA has effectively addressed these recommendations and mitigated the risks associated with engine-fan cowl separation with the issuance of N8900.91, InFO 09013, AD 2003-18-06, and Bombardier's manual change. I plan no additional action on these recommendations, and I request that they are closed-acceptable.

From: NTSB
To: FAA
Date: 7/31/2009
Response: The FAA performed a review of the service difficulty reports (SDR) and original equipment manufacturer/type certificate holder (OEM/TCH) databases and found that multiple airplane models have experienced engine fan cowl separations that could lead to substantial damage to the airplane and affect the safety of flight. The FAA stated that it believes that the problem affects all aircraft models and that human factors risk and design features need to be evaluated to ensure the safety of the aircraft. As a result, the FAA plans to determine the probable cause of improper engine cowl latching by reviewing the current engineering design of latches and of aircraft maintenance manual procedures and inspection instructions. Depending on the results of these reviews, the FAA may require manual revisions or design changes to mitigate the risks, which would require rulemaking. The reviews of the SDR and OEM/TCH databases completed by the FAA were responsive to this recommendation, as is the planned review of latch designs and aircraft maintenance procedures and instructions. Pending completion of these additional reviews and the FAA’s issuing requirements to revise manuals or latch designs where appropriate, Safety Recommendation A-08-82 is classified OPEN -- ACCEPTABLE RESPONSE.

From: FAA
To: NTSB
Date: 12/31/2008
Response: Letter Mail Controlled 1/27/2009 3:08:53 PM MC# 2090044: - From Robert A. Sturgell, Acting Administrator: FAA Comment. A review of Service Difficulty Reports and Original Equipment Manufacturer/Type Certificate Holder (OEM/TCH) databases indicates that multiple airplane models have experienced engine fan cowl separations. We agree that engine fan cowl separation could lead to substantial damage to the airplane and affect the safety of flight. The Federal Aviation Administration believes that the problem affects all aircraft models. Human factors risk and design features need to be evaluated to ensure the safety of the aircraft. The following is proposed to ensure that engine fan cowls are maintained in a proper manner: 0 In the absence of rulemaking the FAA can not require an operator to have specific Required Inspection Items (RII). However, we are recommending that they include these RIIs in their manual, which is required by section 121.369(b)(2). The FAA will issue a Notice for principal inspectors (PI) with oversight responsibility for operators of Airbus single-aisle and Bombardier CL-600 airplane models. This Notice will advise PIS that they should recommend to operators that their existing aircraft maintenance manual procedures and other maintenance documents be revised to require an RII signoff to confirm engine fan cowls are latched after completing any engine maintenance that involves the opening of an engine fan cowl. We anticipate issuing this notice by July 2009; Develop an Information for Operators (InFO) to inform all operators and PIS of 14 CFR part 121/135 certificate holders of the problems associated with improperly latched engine cowls. This InFO would request that all operators ensure that maintenance personnel and flightcrews are trained and provided guidance on how to inspect engine fan cowls to verify they are properly latched. We anticipate completing this InFO by April 2009; and 0 Work with OEM/TCH to determine the probable cause of improper engine cowl latching. This would include a review of the existing engineering design of latches and of the aircraft maintenance manual procedures or inspection instructions. The results of these reviews may require manual revisions or design changes to mitigate the risks. We expect to have this performed by Aircraft Evaluation Groups by October 2009.