Thrust reverser access cowls

1

FAA Aircraft Certification Service SPECIAL AIRWORTHINESS INFORMATION BULLETIN http://www.faa.gov/aircraft/safety/alerts/SAIB

SAIB: NE-07-25 Date: April 3, 2007 This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin (SAIB) advises you, owners and operators of Bombardier Regional Jet Aircraft Series CL-600-2B19, the importance of implementing the recommendations provided in Bombardier Service Letter RJ-SL-71-006 dated September 7, 2005 and Bombardier Service Bulletins 601R-71-030 and CF34-NAC-71-036 and ISAR Item No. 2004-07-7110. There have been several reports from operators regarding thrust reverser access cowls separating from the aircraft during taxi or flight operations. These events had been confirmed to have occurred after engine maintenance checks and that the access cowls were not correctly secured in accordance with AMM task 71-14-01-400-801. A recent incident of an access cowl separation during take off has been confirmed to have occurred immediately after an engine maintenance check. The departed access cowl struck the left hand horizontal stabilizer and the vertical fin skull cap fairing, causing damage to both structures.

Background

• Bombardier Aerospace issued Service Letter SIL-CF34-NAC-020, dated December 2, 2003, advising operators of CL-600-2B19 Regional Jet Series 100/200 Aircraft and CL-600-2A12 and CL-600-2B16 Challenger Aircraft the recommended maintenance actions in accordance with AMM task 71-14-01-400-801 that are required to make sure the upper and lower access cowls are secured after engine maintenance checks. • Bombardier Aerospace issued In-Service Activities Report (ISAR) Item No. 2004-09-7110, dated September 1, 2004, advising operators of CL-600-2B19 aircraft with “guidance to inspect the engine nose cowl access panel fasteners p/n 40S5-11 or 40S161-1-1AA and grommet p/n 40G15-160S installed on the engine nose cowl access panels.” • Bombardier Aerospace issued Service Bulletin CF34-NAC-71-036, dated May 9, 2005, advising operators of Regional Jet Aircraft Series CL-600-2B19 with instructions on visually inspecting the studs and grommets of the powerplant nacelle access panels for signs of damage or wear and replacing where necessary. • Bombardier Aerospace issued Service Letter RJ-SL-71-006, dated September 7, 2005, advising operators of CL-600-2B19 aircraft of the “recommended maintenance actions required to ensure that the thrust reverser upper and lower access cowls are fully secured prior to flight.” • Bombardier Aerospace issued Service Bulletin 601R-71-030, dated September 26, 2005, advising operators of CL-600-2B19 Canadair Regional Jet (CRJ) Aircraft Serial Numbers 7003 thru 7067, 7069 thru 7990, and 8000 thru 8999 with “procedures to do a detailed inspection and if necessary the replacement of the studs and grommets of the nose access panels of the engines.”

2 • Bombardier Aerospace issued All Operator Message No. 983, dated May 26, 2006, to remind operators of CL-600-2B19 aircraft the importance of implementing the recommendations given in Service Letter RJ-SL-71-006 and Service Bulletins 601R-71-030 and CF34-NAC-71-036 to prevent further separations of thrust reverser upper and lower access cowls during flight.

Recommendations

Until the investigation into the incident is completed, we recommend that you, owners and operators of Bombardier Regional Jet Aircraft Series CL-600-2B19, implement the recommendations provided in Bombardier Service Letter RJ-SL-71-006 and Bombardier Service Bulletins 601R-71-030 and CF34- NAC-71-036 and ISAR Item No. 2004-09-7110 to prevent further incidents. The investigation may require further regulatory actions.

For Further Information Contact

Pong K. Lee, Aerospace Engineer FAA, Engine & Propeller Directorate NYACO, ANE-171 1600 Stewart Avenue, Suite 410 Westbury, NY 11590 phone: (516) 228-7324 fax: (516) 794-5531 email: [email protected]