| AD Number | 70-15-04 | Status | Active |
| Effective Date | November 13, 1972 | Issue Date | Not specified |
| Docket Number | Unknown | Amendment | 39-1556 |
| Product Type | ["Aircraft"] | Product Subtype | ["Small/Large Airplane"] |
| CFR Part | --- - Part 39 | CFR Section | N/A |
| Citation | This information is not available. | ||
| Manufacturer(s) | British Aerospace Regional Aircraft |
| Model(s) | H.P. 137 Jetstream Mk. 1 |
70-15-04 HANDLEY PAGE: Amdt. 39-1031 as amended by Amendment 39-1317 is further amended by Amendment 39-1556. Applies to all HP-137 Mark I airplanes having Turbomeca Astazou XIV series engines installed.
To reduce the possibility of inflight failure of the first stage engine turbine disc and subsequent rupture of fuel and hydraulic lines, accomplish the following:
(a) Before further flight, except that the airplane may be flown in accordance with FAR 21.197 to a base where the modification can be performed, modify the fuel and hydraulic systems by relocating the fuel and hydraulic shutoff valves from the engine nacelles to a location on the front spar inboard of the nacelle in accordance with a modification approved by the engineering and manufacturing branch of the nearest FAA regional office.
(b) For first stage turbine discs, P/N 0.261.25.013.0, installed on engines that do not incorporate Turbomeca Mods. TU-123, TU-124, and TU-126, before the accumulation of 400hours total disc time in service or 1,000 cycles, whichever occurs sooner, remove the first stage turbine disc from service and replace it with a new disc of the same part number.
(c) For first stage turbine discs, P/N 0.261.25.013.0 installed with less than 100 hours' time in service since new on engines that incorporate Turbomeca Mods. TU-123, TU-124, and TU-126, installed in accordance with Turbomeca Service Instructions No. 0123, dated August 27, 1970, No. 0124, dated September 16, 1970, and No. 0127, dated September 16, 1970, respectively, or FAA-approved equivalents, before the accumulation of 750 hours total disc time in service or 2,000 cycles, whichever occurs sooner, remove the first stage turbine disc from service and replace it with a disc of the same part number, which has less than 100 hours' time in service since new.
(d) For the purpose of complying with this AD, a cycle constitutes:
(1) Any takeoff and landing operation;
(2) Any touch and go landing operation;
(3) Any other operation where reduction of power is followed by application of takeoff power.
Amendment 39-1031 became effective upon publication in the Federal Register as to all persons except those persons to whom it was made immediately effective by the telegram dated May 15, 1970, which contained this amendment.
Amendment 39-1317 became effective October 5, 1971.
This Amendment 39-1556 becomes effective November 13, 1972.