DC-9 Pylon Fixes
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DC-9 Pylon Fixes
Just an FYI:
U.S. To Require DC-9 Pylon Fixes
by Sean Broderick
11/08/00 10:07:44 AM U.S. EST
FAA has mandated stepped-up inspections and a final fix that targets a nagging fatigue cracking problem on McDonnell Douglas DC-9 engine pylons.
The rule (AD 2000-22-14), published in today’s Federal Register, supersedes a 23-year-old mandate (AD 77-14-19) that requires repetitive radiographic and ultrasonic or eddy current inspections on pylon front spar upper caps, and details optional fixes. In-service reports gathered since the 1977 rule led the manufacturer to conclude that the checks weren’t adequately picking up cracking, however.
Last November, McDonnell Douglas put out a service bulletin (No. DC9-54-030, Revision 06) recommending “improved” X-ray and eddy current inspections on top of the checks already required, and providing guidance on an optional permanent fix. FAA’s rule mandates this bulletin, including the repair.
Operators of DC-9-10s, -20s, -30s, -40s, and -50s and military C-9s must do the X-ray and eddy current inspections within 3,600 hours of the rule’s Dec. 13 effective date or before the aircraft accumulates 8,000 total hours, whichever comes later. One commenter wanted the initial interval bumped up to 3,860 hours to allow a better fit with scheduled maintenance, but FAA denied the request.
Any cracks found must be fixed before further flight. If no cracks are found, repetitive inspections must be done every 3,600 hours. The required spar cap modifications must be done before the aircraft racks up 100,000 hours, or within 3,600 hours of the effective date, whichever comes later.
FAA estimates that some 572 U.S.-registered jets could need the work at a cost of about $37,000 per airplane. The agency notes, however, that some of these DC-9s may have manufacturer-recommended reworks issued over the past decade besides the Nov. 1999 service bulletin, and are in compliance with the new rule as a result.
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Un diva très doué.
U.S. To Require DC-9 Pylon Fixes
by Sean Broderick
11/08/00 10:07:44 AM U.S. EST
FAA has mandated stepped-up inspections and a final fix that targets a nagging fatigue cracking problem on McDonnell Douglas DC-9 engine pylons.
The rule (AD 2000-22-14), published in today’s Federal Register, supersedes a 23-year-old mandate (AD 77-14-19) that requires repetitive radiographic and ultrasonic or eddy current inspections on pylon front spar upper caps, and details optional fixes. In-service reports gathered since the 1977 rule led the manufacturer to conclude that the checks weren’t adequately picking up cracking, however.
Last November, McDonnell Douglas put out a service bulletin (No. DC9-54-030, Revision 06) recommending “improved” X-ray and eddy current inspections on top of the checks already required, and providing guidance on an optional permanent fix. FAA’s rule mandates this bulletin, including the repair.
Operators of DC-9-10s, -20s, -30s, -40s, and -50s and military C-9s must do the X-ray and eddy current inspections within 3,600 hours of the rule’s Dec. 13 effective date or before the aircraft accumulates 8,000 total hours, whichever comes later. One commenter wanted the initial interval bumped up to 3,860 hours to allow a better fit with scheduled maintenance, but FAA denied the request.
Any cracks found must be fixed before further flight. If no cracks are found, repetitive inspections must be done every 3,600 hours. The required spar cap modifications must be done before the aircraft racks up 100,000 hours, or within 3,600 hours of the effective date, whichever comes later.
FAA estimates that some 572 U.S.-registered jets could need the work at a cost of about $37,000 per airplane. The agency notes, however, that some of these DC-9s may have manufacturer-recommended reworks issued over the past decade besides the Nov. 1999 service bulletin, and are in compliance with the new rule as a result.
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Un diva très doué.
