AD/BAe 146/120 Wing Top Skin under Rib 0 Joint Strap (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

British Aerospace BAe 146 Series Aeroplanes

AD/BAe 146/120 Wing Top Skin under Rib 0 Joint Strap 6/2006 DM

Applicability:

Model BAe 146 100 Series aircraft, serial number E1144 and subsequent.

Model BAe 146 200 Series aircraft, serial number E2148 and subsequent.

Model BAe 146 300 Series aircraft, serial number E3141 and subsequent.

Model AVRO 146-RJ70 Series aircraft, serial numbers E1223 through E1267.

Model AVRO 146-RJ85 Series aircraft, serial numbers E2208 through E2277, and E2288.

Model AVRO 146-RJ100 Series aircraft, serial numbers E3221 through E3276, and E3282, E3283, E3284, and E3286.

Requirement:

From the effective date of this Directive, establish if the aircraft has existing repairs to cracks on the wing top skin and whether the area has been inspected in accordance with radiographic technique NTM Part 2, 57-10-12 at Revision 23 or later, and perform the following:

1.    For aircraft with repairs and where the NTM Part 2, 57-10-12 Revision 23 or later inspection has not been performed:

Inspect the wing top skin beneath the Rib ‘0’ in accordance with paragraph 2.C.(1) of BAe 146 Series/AVRO 146-RJ Inspection Service Bulletin (ISB)
57-A071 original issue, or later approved revision.

2.    a.     For BAe 146 Series 100, 200, and 300 Series aircraft without repairs and where the NTM Part 2, 57-10-12 Revision 23 or later inspection has not been performed:

Inspect the wing top skin beneath the Rib ‘0’ in accordance with paragraph 2.C.(1) of BAe 146 Series/AVRO 146-RJ ISB 57-A071 original issue, or later approved revision.

2.    b.    For AVRO RJ-70, -85, and -100 Series aircraft without repairs and where the NTM Part 2, 57-10-12 Revision 23 or later inspection has not been performed:

Inspect the wing top skin beneath the Rib ‘0’ in accordance with paragraph 2.C.(1) of BAe 146 Series/AVRO 146-RJ ISB 57-A071 original issue, or later approved revision.

3.    For aircraft where the NTM Part 2, 57-10-12 Revision 23 or later inspection has been performed:

Inspect the wing top skin beneath the Rib ‘0’ in accordance with paragraph 2.C.(1) of BAe 146 Series/AVRO 146-RJ ISB 57-A071 original issue, or later approved revision.

AND,

4.    Repeat the inspection of the wing top skin beneath the Rib ‘0’ in accordance with paragraph 2.C.(1) of BAe 146 Series/AVRO 146-RJ ISB 57-A071 original issue, or later approved revision.

AND,

5.    Where the inspection carried out in accordance with paragraph 2.C.(1) of BAe 146 Series/AVRO 146-RJ ISB 57-A071 original issue, or later approved revision, identifies a defect in the wing top skin, accomplish a further inspection of the wing top skin and stringers in accordance with paragraph 2.C.(2) of BAe 146 Series/AVRO 146-RJ ISB 57-A071 original issue, or later approved revision.

Note:  EASA Emergency AD 2006-0091-E refers.

Compliance:

1.    Within 500 flights or 3 months after 26 April 2006, whichever occurs first.

2.a. Within 1,000 flights or 6 months after 26 April 2006, whichever occurs first.

2.b. Within 1,500 flights or 1 year after 26 April 2006, whichever occurs first.

3.    Within 4,000 flights or 2 years after 26 April 2006, whichever occurs first.

4.    At intervals not to exceed 4,000 flights or 2 years, whichever occurs first.

5.    Before further flight.

This Airworthiness Directive becomes effective on 26 April 2006.

Background: A significant crack has been found in the wing top skin under the Rib 0 joint strap during a scheduled inspection of the adjacent structure.  The possibility exists of similar cracks on other aircraft with top wing skins made from the same aluminium alloy as the subject aircraft.  Inspections are required on these affected aircraft to maintain the structural integrity of the wing.

Richard Castles
Delegate of the Civil Aviation Safety Authority

21 April 2006