Airworthiness Directive · Amendment 39-14151 · McDonnell Douglas Model MD-90-30 Airplanes
McDonnell Douglas Model MD-90-30 Airplanes
This AD applies to all McDonnell Douglas Model MD-90-30 airplanes, certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for all McDonnell Douglas Model MD-90-30 airplanes. This AD requires replacing existing dual anti-skid control manifolds (DACM) with new, improved or reworked and reidentified DACMs; inspecting the inlet filters and other components of the DACMs for damage; replacing any damaged DACM components with new or serviceable components; and flushing/cleaning the braking system prior to replacing the inlet filters. This AD is prompted by reports of multiple incidents of blown tires on landing while using maximum autobrake. We are issuing this AD to prevent metallic fibers from the first stage filter of the servo valves inside the DACM from becoming lodged in the first stage nozzle of the servo valve, which could lead to tire failure during high speed/high energy braking and possible subsequent runway departure.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 18 months after the effective date of this AD, replace existing DACMs with new, improved or reworked and reidentified DACMs, part number 6006079-2, by doing all actions in accordance with the Accomplishment Instructions of Boeing Service Bulletin MD90-32-056, dated October 7, 2003.
Note 1: Boeing Service Bulletin MD90-32-056 refers to Aircraft Braking Systems Corporation (ABSC) Service Bulletin MD-90 6006079-32-02, dated August 7, 2003, as an additional source of service information for installing new, improved or reworked and reidentified DACMs.
Prior to or concurrently with the accomplishment of paragraph (f) of this AD, perform paragraphs (g)(1) and (g)(2) of this AD in accordance with the Accomplishment Instructions of Boeing Service Bulletin MD90-32-043, Revision 01, dated November 9, 2000.
(1) Perform a detailed inspection of the metered pressure inlet filters and other components of the DACM for damage. Replace any damaged DACM components with new or serviceable components, and flush/clean the braking system, as applicable.
(2) Replace the metered pressure inlet filters of the DACM assembly with new filters.
Note 2: Boeing Service Bulletin MD90-32-043, Revision 01, refers to ABSC Service Bulletin MD90-32-12, dated January 12, 2000, as an additional source of service information for inspecting the components of the DACM assembly for uncleanliness, structural damage or excessive wear that may render the DACM inoperable, and for replacing those components with new or serviceable components, if necessary.
Note 3: For the purposes of this AD, a detailed inspection is “an intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.”
Inspecting and replacing DACM inlet filters and flushing/cleaning braking systems before the effective date of this AD in accordance with Boeing Service Bulletin MD90-32-043, dated April 10, 2000, is considered acceptable for compliance with the corresponding actions specified in this AD.
