Airworthiness Directive · Amendment 39-16389 · Engine exhaust
The Boeing Company Model 777-200LR and -300ER Series Airplanes Equipped with GE90-100 Series Engines
This AD applies to The Boeing Company Model 777-200LR and -300ER series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 777-78A0070, dated November 20, 2008.
We are adopting a new airworthiness directive (AD) for certain Model 777-200LR and -300ER series airplanes equipped with GE90-100 series engines. This AD requires replacing the insulation blanket fasteners of the lower aft cowl of the thrust reverser. This AD also requires inspecting the oil scavenge tube on the turbine rear frame of the engine for damage, and replacement if necessary. This AD results from a determination of insufficient clearance and subsequent interference between the oil scavenge tube on the turbine rear frame of the engine and the bolt on the aft cowl insulation blanket of the thrust reverser. We are issuing this AD to prevent damage and possible puncture of the oil scavenge tube and consequent oil loss, which could result in an in-flight shutdown of the engine.
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 180 days or 300 flight cycles after the effective date of this AD, whichever is later: Replace the insulation blanket fasteners of the lower aft cowl of the thrust reverser, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 777-78A0070, dated November 20, 2008.
Before or concurrently with accomplishing the requirements in paragraph (g) of this AD: Do a detailed inspection of the oil scavenge tube on the turbine rear frame of the engine for damage, in accordance with the Accomplishment Instructions of General Electric GE90-100 Service Bulletin 79-0017, dated March 3, 2008. If any damage is found, before further flight, replace the tube, in accordance with the Accomplishment Instructions of General Electric GE90-100 Service Bulletin 79-0017, dated March 3, 2008.
Note 1: 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.”
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
