Airworthiness Directive · Amendment 39-18707 · Fuselage
The Boeing Company Airplanes
This AD applies to all The Boeing Company Model MD-90-30 airplanes, certificated in any category.
We are adopting a new airworthiness directive (AD) for all The Boeing Company Model MD-90-30 airplanes. This AD requires a detailed inspection of the forward and aft surfaces on the left and right sides at the cant station 1520 bulkhead for any crack in the upper cap and (cap) doubler, webs and doublers, stiffeners, and the lower tee cap between longerons 3 through 11, and repairs if necessary. This AD was prompted by a report of cracking in various structures in the fuselage cant station 1520 bulkhead. We are issuing this AD to detect and correct cracking in the bulkhead, which could result in reduced structural integrity of the airplane.
At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin MD90-53A037, dated September 19, 2016, except as required by paragraph (j) of this AD: On the left and right sides at the cant station 1520 bulkhead, do a detailed inspection of the forward and aft surfaces, for any crack in the upper cap and (cap) doubler, webs and doublers, stiffeners, and the lower tee cap between longerons 3 through 11, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-53A037, dated September 19, 2016.
If any crack is found in the bulkhead web or doubler, do the repair in accordance with Boeing Alert Service Bulletin MD90-53A037, dated September 19, 2016. Do all repairs before further flight.
If any non-web or non-doubler crack is found in the bulkhead, repair before further flight using a method approved in accordance with the procedures specified in paragraph (l) of this AD.
Where paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin MD90-53A037, dated September 19, 2016, specifies a compliance time “after the original issue date of this service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
