Airworthiness Directive · Amendment 39-11875 · British Aerospace Model BAe 146 and Model Avro 146-RJ Series Airplanes
British Aerospace Model BAe 146 and Model Avro 146-RJ Series Airplanes
All Model BAe 146 series airplanes; and Model Avro 146-RJ series airplanes, as listed in British Aerospace Service Bulletin SB.57-56, dated September 2, 1999; certificated in any category; except those on which British Aerospace Modification HCM01307A or HCM01307B [Reference Repair Instruction (R.I.L. HC571H9033)] has been accomplished.
Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise 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 amendment adopts a new airworthiness directive (AD), applicable to all British Aerospace Model BAe 146 and certain Model Avro 146-RJ series airplanes, that requires inspections and torque checks of the stringer crown fittings and bolts at Ribs 0 and 2 of the wings for discrepancies, corrective action, if necessary; and eventual modification of the stringer crown fittings, which terminates the inspections and checks. This amendment is necessary to prevent increased loads on the upper wing skin due to looseness of the stringer fittings and bolts at Ribs 0 and 2 of the wings, which could result in reduced structural integrity of the wings. This action is intended to address the identified unsafe condition.
To prevent increased loads on the upper wing skin due to looseness of the stringer fittings and bolts at Ribs 0 and 2 of the wings, which could result in reduced structural integrity of the wings, accomplish the following:
(a) Prior to the accumulation of 14,000 total flight cycles, or within 4,000 flight cycles after the effective date of this AD, whichever occurs later: Perform a detailed visual inspection of the stringers and a torque check of the Jo-bolts at Ribs 0 and 2 of the wings for discrepancies (including loose Jo-bolts and stringer crown fittings, fretting of fittings and stringers, and cracking or damage of attachments); in accordance with British Aerospace Service Bulletin SB.57-56, dated September 2, 1999.
(1) If no discrepancy is found, or, if 1, 2, or 3 loose Jo-bolts are found per rib side and no loose crown (dagger) fittings are found (Category 1 or 2, as specified in Table 2 of paragraph D. “Compliance” of the service bulletin), accomplish the actions required in paragraphs (a)(1)(i) and (a)(1)(ii) of this AD.
(i) Repeat the inspection thereafter at the applicable times specified in Table 2, until accomplishment of the actions required by paragraph (a)(1)(ii) of this AD.
(ii) Prior to accumulation of 40,000 total flight cycles, or within 4,000 flight cycles after the effective date of this AD, whichever occurs later: Modify all stringer crown fittings at Ribs 0 and 2 of the wings (including inspections, repairs, and installation of oversize interference fit fasteners per R.I.L. HC571H9033) in accordance with the service bulletin, except as required by paragraph (b) of this AD. This modification terminates the requirements of this AD.
(2) If any other discrepancy is found, as specified in Table 2 (Categories 3 through 6): At the applicable times specified in Table 2, repeat the inspection thereafter, and modify all crown fittings at Ribs 0 and 2 of the wings (including inspections, repairs, and installation of oversize interference fit fasteners per R.I.L. HC571H9033); in accordance with the service bulletin, except as required by paragraph (b) of this AD. This modification terminates the requirements of this AD.
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.”
(b) Where British Aerospace Service Bulletin SB.57-56, dated September 2, 1999, specifies to contact the manufacturer for a repair, prior to further flight, repair in accordance with a method approved by either the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate; or the Civil Aviation Authority of the United Kingdom (or its delegated agent). For a repair method to be approved by the Manager, International Branch, ANM-116, as required by this paragraph, the Manager's approval letter must specifically reference this AD.
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
