Airworthiness Directive · Amendment 39-18036 · Standard practices/structures
The Boeing Company Airplanes
This AD applies to all The Boeing Company Model MD-90-30 airplanes, certificated in any category.
We are superseding Airworthiness Directive (AD) 97-11-07 and AD 99-18-23, which apply to all The Boeing Company Model MD-90-30 airplanes. AD 97-11-07 and AD 99-18-23 required revising the Airworthiness Limitations Section (ALS) of the Instructions for Continued Airworthiness to incorporate certain compliance times for principal structural element (PSE) inspections and replacement times for safe-life limited parts. This new AD also requires revising the maintenance or inspection program to incorporate a new PSE requirement for the rear spar caps of the horizontal stabilizer and its associated inspections, which would terminate certain inspections of the horizontal stabilizer rear spar. This AD was prompted by an analysis of data that identified a need to introduce a new PSE requirement for the rear spar caps of the horizontal stabilizer. We are issuing this AD to detect and correct fatigue cracking of PSEs and certain safe-life limited parts, which could adversely affect the structural integrity of the airplane.
This paragraph restates the requirements of paragraph (a) of AD 97-11-07, Amendment 39-10036 (62 FR 27941, May 22, 1997). Within 180 days after June 26, 1997 (the effective date of AD 97-11-07), revise the Airworthiness Limitations Section of the Instructions for Continued Airworthiness to incorporate the Item, Location, and Inspection Interval of PSEs identified in paragraphs (g)(1) through (g)(3) of this AD. This may be accomplished by inserting a copy of this AD into the ALI, or by using a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA.
(1) For Item 53.30.02.3 at Skin Panels, station (STA) 237 to 1395 Fuselage Skin in Constant Section from Longeron 3 Left to Longeron 3 Right: the initial interval is 60,000 landings. Repeat the inspection thereafter at intervals not to exceed 11,000 landings.
(2) For Item 53.30.02.4 at Skin Panels, STA 237 to 1395 Fuselage Hoop Skin Splice in Constant Section from Longeron 5 Left to Longeron 5 Right: the initial interval is 60,000 landings. Repeat the inspection thereafter at intervals not to exceed 30,000 landings.
(3) For Item 54.10.04.1 at Thrust Bulkhead, Pylon—STA Yn 170.5—Rear Spar and Engine Thrust Support Fitting (Upper and Lower): the initial interval is 15,000 landings. Repeat the inspection thereafter at intervals not to exceed 4,500 landings.
This paragraph restates the requirements of paragraph (b) of AD 97-11-07, Amendment 39-10036 (62 FR 27941, May 22, 1997). Within 180 days after June 26, 1997 (the effective date of AD 97-11-07), revise the Airworthiness Limitations Section of the Instructions for Continued Airworthiness to incorporate the Item, Location, and Inspection Interval of PSE 55.13.01.1 at Plates/Skin—Upper STA Xh 27.2 Left to Xh 27.2 Right—Upper Aft Skin Plank with Integral Stringers from Xh 7.234 to Xh 26.859. The initial interval is 60,000 landings. Repeat the inspection thereafter at intervals not to exceed 8,100 landings. This may be accomplished by inserting a copy of this AD into the ALI, or using a method approved by the Manager, Los Angeles ACO, FAA.
This paragraph restates the restriction on alternative inspections and inspection intervals required by paragraph (c) of AD 97-11-07, Amendment 39-10036 (62 FR 27941, May 22, 1997). Except as provided by paragraphs (l) and (o) of this AD: After the actions required by paragraphs (g) and (h) of this AD have been accomplished, no alternative inspections or inspection intervals may be approved for the parts specified in paragraphs (g) and (h) of this AD.
This paragraph restates the requirements of paragraph (a) of AD 99-18-23, Amendment 39-11289 (64 FR 48284, September 3, 1999). Within 180 days after October 8, 1999 (the effective date of AD 99-18-23, Amendment 39-48284 (64 FR 48284, September 3, 1999)), revise the Airworthiness Limitations Section of the Instructions for Continued Airworthiness to incorporate the Part Number, Item, and Mandatory Replacement Time of certain safe-life limited parts by inserting McDonnell Douglas Airworthiness Limitations Instructions (ALI), Report No. MDC-94K9000, Revision 3, dated November 1997, into the ALI.
This paragraph restates the restriction on alternative replacement times required by paragraph (b) of AD 99-18-23, Amendment 39-11289 (64 FR 48284, September 3, 1999). Except as provided by paragraphs (l) and (o) of this AD: After the actions required by paragraph (j) of this AD have been accomplished, no alternative replacement times may be approved for the safe-life limited parts specified in McDonnell Douglas Airworthiness (Airworthiness Limitations Instructions (ALI) Report No. MDC-94K9000, Revision 3, dated November 1997.
Within 180 days after the effective date of this AD, revise the maintenance or inspection program, as applicable, to incorporate the tasks specified in Boeing MD-90 Airworthiness Limitations Instructions (ALI), Report No. MDC-94K9000, Revision 6, dated September 2011. The compliance times for the initial compliance time and repetitive intervals for the tasks are stated in Boeing MD-90 Airworthiness Limitations Instructions (ALI), Report No. MDC-94K9000, Revision 6, dated September 2011. Doing the revision required by this paragraph terminates the revisions required by paragraphs (g), (h), and (j) of this AD.
After accomplishing the revision required by paragraph (l) of this AD, no alternative actions (e.g., inspections) or intervals may be used unless the actions or intervals are approved as an AMOC in accordance with the procedures specified in paragraph (o) of this AD.
