COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Partenavia P68 Series Aeroplanes
AD/P68/22
Amdt 4
Wing Lower Front and Rear Spar Assemblies 2/86
Applicability: All P68 series aircraft up to and including S/No 347.
Requirement: Inspect the wing front and rear spars for cracks in accordance with Partenavia Service Bulletin No. 65 Revision 2.
- Aircraft inspected in accordance with the initial issue of this AD require further inspection in accordance with this amendment.
Inspections carried out in accordance with Amendment 1 or later issues of this directive, satisfy the inspection requirements of this amendment.
2. Accomplishment of the front spar modification in accordance with this, or previous, issues of this Directive, constitutes terminating action for the front spar repetitive inspection requirements of this Directive.
3. Aircraft on which the rear spar modification was accomplished prior to the issue of Amendment 3, require further rework in accordance with this issue. Accomplishment of the rear spar modification in accordance with Amendment 3 or later issues constitutes terminating action for the rear spar repetitive inspection requirements of this Directive.
4. When carrying out the modifications to front and/or rear spars, reinforcement plates and fasteners should be wet assembled with jointing compound or sealant (Hylomar SQ-32, PR1436G, PR1422 or similar) to prevent corrosion.
5. When carrying out the modification to the rear spar the following additional requirements must be met:
- The Avdel 5/32" dia. blind rivets specified on Partenavia rear spar drawing R- 0081 cannot be locked without using a special pulling head which is not readily available in Australia. Substitution of 3/16" dia. high strength structural rivets or close-tolerance steel bolts is required. Some approved types are listed below. Grip lengths are not specified because of variations between individual assemblies. This list is not exhaustive, but alternative proposals will require approval in the normal manner.
Rivets (Hole size .192"/.196") Cherrymax CR3523P-6
Bulbed Cherrylock CR2539P-6 “ “ CR2839CW-6
Cherrylock CR2663CW-6 “ CR2563-6
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Bolts (Hole size .1895"/.1915") NAS 1103
AN173
AN173C (however AN173 is preferred)
Nuts must be aircraft quality and either lockable or self-locking. Use of washers should be in accordance with sound aeronautical practice.
b. All fastener edge distances must be 0.315" minimum as shown on Partenavia drawing R 0081 Section A.
Compliance: 1. For all aircraft which have achieved 1800 hours time in service:- within 25 hours time in service after 20 September 1984, and thereafter at intervals not exceeding 500 hours time in service.
2. For all other aircraft - before achieving 1800 hours time in service, and thereafter at intervals not exceeding 500 hours time in service.
3. For all aircraft on which the rear spar modification detailed in SB No. 65 was accomplished prior to the issue of Amendment 3, the variations to SB No. 65 contained in the Requirements above must be incorporated prior to the issue of the next maintenance release after 1 December 1984.
Background: A number of Australian aircraft have developed cracks in the front and rear lower spar cap angles. The critical area in each case is the radius run-out where the horizontal flange abruptly tapers down near the wing-fuselage attachment. As a result of these reports the manufacturer issued SB No. 65 which detailed an improved inspection method, and a repair for the front spar only. This directive was later amended to incorporate SB No. 65 Revision 1, which included the rear spar, however some variations to the rear spar repair scheme were, and still are, required.
This latest amendment introduces SB No 65 Revision 2, which contains a re-designed front spar reinforcement. However, the previous modification is still considered to be satisfactory. Later S/No aircraft are now also exempt from the requirements of this Directive.