| AD Number | 73-12-07 | Status | Active |
| Effective Date | July 05, 1973 | Issue Date | Not specified |
| Docket Number | Unknown | Amendment | 39-1655 |
| Product Type | ["Aircraft"] | Product Subtype | ["Large Airplane"] |
| CFR Part | --- - Part 39 | CFR Section | N/A |
| Citation | This information is not available. | ||
| Manufacturer(s) | Vickers-Armstrongs (Aircraft Limited) |
| Model(s) | Viscount 744 Viscount 745D Viscount 810 |
73-12-07 BRITISH AIRCRAFT CORPORATION: Amdt. 39-1655. Applies to Viscount Model 744, 745D, and 810 Series airplanes.
Compliance is required as indicated.
To prevent failures of the nacelle structure tubes and end fittings on high time engine nacelle structures due to fatigue and corrosion, accomplish the following:
(a) For airplanes which have not been inspected in accordance with paragraph (h) of AD 66-12-3 prior to the effective date of this AD, -
(1) Within the next 500 landings or 12 calendar months, whichever occurs sooner, after the effective date of this AD, and thereafter at intervals not to exceed 7,500 landings form the last inspection, comply with paragraph (e); and
(2) Within the next 500 landings after the effective date of this AD or before the accumulation of 19,000 total landings, whichever occurs later, and thereafter at intervals not to exceed 7,500 landings from the last inspection, comply with paragraph (d).
(b) For airplanes which haveaccumulated 5,500 or more landings since compliance with paragraph (h) of AD 66-12-3, within the next 2,000 landings after the effective date of this AD, or before the accumulation of 19,000 total landings, whichever occurs later, and thereafter at intervals not to exceed 7,500 landings from the last inspection, comply with paragraphs (d) and (e).
(c) For airplanes which have accumulated less than 5,500 landings since compliance with paragraph (h) of AD 66-12-3 on the effective date of this AD, within the next 7,500 landings after compliance with paragraph (h) of AD 66-12-3 or, before the accumulation of 19,000 total landings , whichever occurs later, and thereafter at intervals not to exceed 7,500 landings from the last inspection, comply with paragraphs (d) and (e).
(d) Inspect the engine nacelle structure tubes and end fittings for cracks at the positions specified for the applicable technique in figures 1 and 2 of British Aircraft Corporation (BAC) Ltd., Preliminary Technical Leaflet (PTL) No. 258, Issue 4 (700 Series), dated August 31, 1971, or No. 122, Issue 4 (800/810 Series), dated August 31, 1971, using dye penetrant, radiographic, and ultrasonic resonance methods in accordance with Techniques 1, 3, and 4, respectively, of the applicable PTL or an FAA-approved equivalent.
(e) Inspect the engine nacelle structure tubes for internal corrosion at the positions specified for Technique 2 in figures 1 and 2 of BAC Ltd. PTL No. 258, Issue 4 (700 Series), dated August 31, 1971, or No. 122, Issue 4 (800/810 Series), dated August 31, 1971, using the radiographic method in accordance with Technique 2 of the applicable PTL or an FAA-approved equivalent.
(f) If, during an inspection required by paragraph (a), (b), or (c), any end fittings are found cracked, or any tubes are found cracked or corroded beyond the limits specified in the applicable PTL, before further flight replace the affected parts with serviceable parts of the same part number.
Thissupersedes Amendment 39-231 (31 F.R. 6790), AD 66-12-3.
This Amendment becomes effective July 5, 1973.