Airworthiness Directive · Amendment 39-12051 · Airbus Model A330 Series Airplanes
Airbus Model A330 Series Airplanes
Model A330 series airplanes equipped with Pratt & Whitney 4000 series engines, certificated in any category; fitted with engine aft mount nuts and bolts installed in accordance with Airbus Modification 46948 (installed on in-service airplanes per Airbus Service Bulletin A330-71-3012).
Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
This document publishes in the Federal Register an amendment adopting airworthiness directive (AD) 2000-25-53, which was sent previously to all known U.S. owners and operators of Airbus Model A330 series airplanes by individual notices. This AD requires either repetitive detailed visual inspections or repetitive borescopic inspections to detect cracking or other damage of the barrel nuts of the engine aft mount; and replacement of any cracked nut and its associated bolt with a new nut and bolt, or replacement of all 4 nuts and their associated bolts if two or more nuts on the same engine mount are found cracked. This action is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to detect and correct cracking of the aft engine mount nut, which could result in reduced structural integrity of the engine-to-pylon aft mount assembly, or, in the case of multiple cracked nuts, possible loss of an engine.
To detect and correct cracking of the aft engine mount nut, which could result in reduced structural integrity of the engine-to-pylon aft mount assembly, or, in the case of multiple cracked nuts, possible loss of an engine, accomplish the following:
(a) Before the next flight, perform either a detailed visual or borescopic inspection to detect cracking or other damage of all 4 barrel nuts of each engine aft mount, in accordance with paragraph 4.2.1 of Airbus All Operators Telex (AOT) A330-71A3014, dated December 8, 2000. If any cracking or damage is detected, before further flight, replace nuts and their associated bolts, as applicable, in accordance with paragraph 4.2.2 of the AOT. Repeat the inspection thereafter at least every 50 flight cycles.
Note 2: For the purposes of this AD, a detailed visual inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”
Note 3: Airbus AOT A330-71A3014, dated December 8, 2000, refers to Pratt & Whitney Service Bulletin PW4G-100-71-16, Revision 1, dated September 15, 1999, as an additional source of service information for replacing the nuts and bolts.
