Airworthiness Directive · Amendment 39-11988 · Boeing Model 747 Series Airplanes Powered by Pratt & Whitney JT9D-3 and -7 Series Engines
Boeing Model 747 Series Airplanes Powered by Pratt & Whitney JT9D-3 and -7 Series Engines
Superseded. A later AD replaced this one: AD 2001-15-02. Comply with the one in force.
Model 747 series airplanes, certificated in any category, as listed in Boeing Alert Service Bulletin 747-54A2203, dated August 31, 2000; except Model 747 series airplanes having serial numbers 21048 and 20887.
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 (c) 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 corrects a minor error that appeared in airworthiness directive (AD) 2000-23-16, that was published in the Federal Register on November 21, 2000 (65 FR 69862). The error resulted in a reference to a part number that does not exist. That AD is applicable to certain Boeing Model 747 series airplanes, and requires repetitive inspections and torque checks of the hanger fittings and strut forward bulkhead of the forward engine mount and adjacent support structure, and corrective actions, if necessary. That AD also provides for optional terminating action for the repetitive inspections and checks.
To detect and correct loose fasteners and associated damage to the hanger fittings and strut forward bulkhead of the forward engine mount, which could result in separation of the engine from the airplane, accomplish the following:
(a) Within 60 days after the effective date of this AD: Perform a detailed visual inspection and torque check as specified in Part 2 of Boeing Alert Service Bulletin 747-54A2203, dated August 31, 2000, to detect loose fasteners and associated damage to the hanger fittings and bulkhead of the forward engine mount, in accordance with Figure 1 of the alert service bulletin. Repeat the inspections/checks thereafter at the applicable intervals specified in Figure 1 of the alert service bulletin.
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.”
(1) If no loose fastener or associated damage is detected, repeat the inspections/checks thereafter at the applicable intervals specified in Figure 1 of the alert service bulletin until accomplishment of the terminating action specified in paragraph (b) of this AD.
Note 3: Where there are differences between the AD and the alert service bulletin, the AD prevails.
(2) If any loose fastener or associated damage is detected, before further flight, perform the applicable corrective actions (torque check, rework or replacement of fittings), as specified in Figure 1 of the alert service bulletin. Repeat the inspections/checks thereafter at the applicable intervals specified in Figure 1 of the alert service bulletin until accomplishment of the terminating action specified in paragraph (b) of this AD. Where the alert service bulletin specifies that the manufacturer may be contacted for disposition of certain corrective actions (rework or replacement of fittings), this AD requires such rework and/or replacement to be done in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or in accordance with data meeting the type certification basis of the airplane approved by a Boeing Company designated engineering representative (DER) who has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the Manager's approval letter must specifically reference this AD.
(b) Accomplishment of the terminating action specified in Part 6 of Boeing Alert Service Bulletin 747-54A2203, dated August 31, 2000, constitutes terminating action for the repetitive inspections/checks required by paragraph (a) of this AD.
Note 4: Installation of two BACW10BP* auxiliary power unit washers on Group A fasteners accomplished prior to the effective date of this AD in accordance with Boeing Service Bulletin 747-54A2159, dated November 3, 1994, Revision 1, dated June 1, 1995, or Revision 2, dated March 14, 1996; and pin or bolt protrusion as specified in the 747 Structural Repair Manual, Chapter 51-30-02 (both referenced in Boeing Alert Service Bulletin 747-54A2203, dated August 31, 2000); is considered acceptable for compliance with the terminating action specified in paragraph (b) of this AD.
