76-14-01 DEHAVILLAND: Amendment 39-2661.
1. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 2 through 17, certificated in all categories, that have not been altered in accordance with DeHavilland Aircraft of Canada, Ltd. Engineering Bulletin Series DHC-4 No. 11.
Compliance required as indicated.
Within the next 50 hours' time in service after the effective date of this AD, inspect and alter the rivets attaching the hinge plates to the outboard hinge arms on the inboard trailing flap assemblies in accordance with DeHavilland Engineering Bulletin Series DHC-4 No. 11 or with an equivalent inspection and alteration.
2. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 2 through 22, 24, and 25, certificated in all categories, that have not been altered in accordance with DeHavilland Aircraft of Canada, Ltd. Modification Bulletin No. 4/1101, Issue 4.
Compliance required as indicated.
(a) Within the next 100 hours' time in service after the effective date of this AD, inspect and alter the rudder ribs in accordance with DeHavilland Modification Bulletin No. 4/1101, Issue 4, or with an equivalent inspection and alteration.
(b) Repeat the inspection noted in paragraph (a) above at intervals not to exceed 100 hours' time in service until the alteration in DeHavilland Modification Bulletin No. 4/1101, Issue 4, or an approved equivalent, has been incorporated.
3. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 2 through 39, except S/N 23 and 28, certificated in all categories that have not been altered in accordance with DeHavilland Aircraft of Canada, Ltd. Modification Bulletin No. 4/1099, Issue 3.
Compliance required as indicated.
(a) Within the next 250 hours' time in service after the effective date of this AD, inspect all electrofilm "unibal" spherical bearings in the flap hinge arms in accordance with DeHavilland Modification Bulletin No. 4/1099, Issue 3, or with an equivalent inspection.
(b) Repeat the inspection noted in paragraph (a) above at intervals not to exceed 250 hours' time in service until the replacement of all electrofilm bearings in the flap hinge arms has been accomplished with sintered bronze teflon lined unibal bearings in accordance with DeHavilland Modification Bulletin No. 4/1099, Issue 3, or with an equivalent alteration.
4. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 1 through 43, 45, 46, 47, 49, 50, 51, 53, 54, 55, 57, 58, and 59, certificated in all categories, that have not been altered in accordance with DeHavilland Aircraft of Canada, Ltd. Modification Bulletin No. 4/1150, Issue 3.
Compliance required as indicated.
(a) Within the next 50 hours' time in service after the effective date of this AD, inspect the left and right root fore flaps for external skin cracks if the flap has accumulated 300 hours' flying time.
(b) Repeat the inspection noted in paragraph (a) above at intervals not to exceed 50 hours' time in service.
(c) If the inspection indicated rib damage, or if the flap has accumulated 1000 hours' time in service, remove the flap and alter, before further flight, in accordance with DeHavilland Modification Bulletin No. 4/1150, Issue 3, or with an equivalent alteration.
5. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 4 through 57, except S/N 6, 13, 17, 21, 23, 26, 34, 40, 55, and 56, certificated in all categories, that have not been altered in accordance with DeHavilland Aircraft of Canada Ltd. Engineering Bulletin, Series DHC-4, No. 18.
Compliance required as indicated.
To preclude the possible hazard of a fire created by loose terminal lug attachment to the end of aluminum electrical cable assemblies, accomplish the following:
(a) Within the next 200 hours' time in service after the effective date of this AD, inspect, test, and where necessary, replace aluminum electrical cable assembliesin accordance with DeHavilland Engineering Bulletin, Series DHC-4, No. 18 or with an equivalent inspection and test.
6. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 2 through 38, except S/N 23 and 34, certificated in all categories, that have not been altered in accordance with DeHavilland Aircraft of Canada, Ltd. Modification Bulletin No. 4/1182, Issue 2.
Compliance required as indicated.
To prevent possible failure of the main landing gear to fully extend and lock, accomplish the following:
(a) Within the next 100 hours' time in service after the effective date of this AD, install a spacer sleeve, P/N 5735-5, into the upper end fitting, P/N 5705-5, of the main landing gear shortening mechanism assembly, P/N 5700-7, in accordance with DeHavilland Modification Bulletin No. 4/1182, Issue 2, or with an equivalent alteration.
Equivalent parts, inspections, procedures, instructions, repairs and alterations must be approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.
Upon submission of substantiating data by an owner or operator through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA Eastern Region, may adjust the inspection time in this Airworthiness Directive.
Compliance with the Airworthiness Directive must be noted in the log book of the aircraft by referencing the Airworthiness Directive number and the specific item complied with: i.e. AD 76 - - - (4) if item 4 is being complied with.
This amendment is effective July 12, 1976.