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AD 76-26-01 ACTIVE

H.P. Turbine Disc
Key Information
AD Number 76-26-01 Status Active
Effective Date January 03, 1977 Issue Date Not specified
Docket Number Unknown Amendment 39-2790
Product Type ["Engine"] Product Subtype Not specified
CFR Part --- - Part 39 CFR Section N/A
Citation This information is not available.
Applicability
Manufacturer(s) Rolls-Royce plc
Model(s) RB211-22B-02 RB211-22B/MOD 72-8700
Regulatory Text

76-26-01 ROLLS-ROYCE (1971) LTD: Amendment 39-2790. Applies to RB.211-22B engines.
Compliance is required as indicated, unless already accomplished.

To prevent hazards of H.P. turbine disc failure from cracks in the disc bore surface, accomplish the following:

(a) For engines not incorporating Rolls-Royce Service Bulletin RB.211-72-3225--with H.P. disc serial numbers CQDY 779, 794, 802, 824, 829, 840, 851, 933 and 952 installed--inspect the H.P. disc bore in accordance with Rolls-Royce Alert Service Bulletin RB.211-72-A4303 dated December 3, 1976, or an FAA-approved equivalent, as follows:

(1) For engines that have accumulated in excess of 2,400 flight cycles, inspect within 10 flight cycles after the effective date of this AD.

(2) For engines that have accumulated in excess of 1,000 flight cycles but less than 2,401 cycles, inspect within 80 flight cycles after the effective date of this AD.

(3) For other engines, inspect within the next 250 flight cycles after the effective date of this AD.

(b) For engines not incorporating Rolls-Royce Service Bulletin RB. 211-72-3225--with H.P. disc serial numbers CQDY 750 and higher, and serial numbers CQDY 577, 624 and 742 (but excluding the serial numbers listed in paragraph (a) of this AD) installed--that have accumulated in excess of 2,300 flight cycles, inspect the H.P. disc bore in accordance with Rolls-Royce Alert Service Bulletin RB.211-72-A4303 dated December 3, 1976, or an FAA-approved equivalent, within the next 100 flight cycles after the effective date of this AD.

(c) For engines incorporating Rolls-Royce Service Bulletin RB.211-72-3225--with H.P. disc serial numbers CQDY 790, 791, 887, 972, 1002, 1016, 1030, 1073 and CQDY 1106 and higher installed--inspect the H.P. disc bore in accordance with Rolls-Royce Alert Service Bulletin RB.211-72-A4303 dated December 3, 1976, or an FAA-approved equivalent, as follows:

(1) For engines that have accumulated in excess of 1,000flight cycles, inspect within the next 10 flight cycles after the effective date of this AD.

(2) For engines that have accumulated in excess of 700 flight cycles but less than 1,001 flight cycles, inspect within the next 50 flight cycles after the effective date of this AD.

(3) For engines that have accumulated in excess of 400 flight cycles but less than 701 flight cycles, inspect within the next 80 flight cycles after the effective date of this AD.

(4) For all other engines inspect within the next 250 flight cycles after the effective date of this AD.

(d) For engines incorporating Rolls-Royce Service Bulletin RB.211-72-3225--with serial numbers CQDY 750 and higher (except those covered in paragraph (c) of this AD) installed--that have accumulated in excess of 900 flight cycles, inspect the H.P. disc bore in accordance with Rolls-Royce Alert Service Bulletin RB.211-72-A4303 dated December 3, 1976, or an FAA-approved equivalent, within the next 100 flight cyclesafter the effective date of this AD.

(e) For engines inspected under paragraphs (a) and (b) of this AD, which are found to be serviceable in accordance with the acceptance standards of Rolls-Royce Alert Service Bulletin RB.211-72-A4303 dated December 3, 1976, or an FAA approved equivalent, either -

(1) Continue to inspect the H.P. disc bore in accordance with Rolls-Royce Alert Service Bulletin RB.211-72-A4303 dated December 3, 1976, or an FAA-approved equivalent, at intervals not to exceed 2,800 flight cycles; or

(2) Rework the H.P. discs in accordance with Rolls-Royce Service Bulletin RB.211-72-4447 dated October 7, 1976, or an FAA-approved equivalent.

(f) For engines inspected under paragraphs (c) and (d) of this AD which are found serviceable in accordance with the acceptance standards of Rolls-Royce Alert Service Bulletin RB.211-72-A4303 dated December 3, 1976, or an FAA-approved equivalent, either -

(1) Continue to inspect the H.P. disc bore in accordance with Rolls-Royce Alert Service Bulletin RB.211-72-A4303 dated December 3, 1976, or an FAA-approved equivalent, at intervals not to exceed 1,500 flight cycles; or

(2) Rework the H.P. discs in accordance with Rolls-Royce Service Bulletin RB.211-72-4447 dated October 7, 1976, or an FAA-approved equivalent.

(g) Replace those discs found not to be serviceable during any inspection required by this AD before further flight with -

(1) A serviceable FAA-approved disc that has been reworked in accordance with Rolls-Royce Service Bulletin RB.211-72-4447 dated October 7, 1976, or an FAA-approved equivalent; or

(2) A serviceable FAA-approved disc that has not been reworked in accordance with Rolls-Royce Service Bulletin RB.211-72-4447 dated October 7, 1976, or an FAA-approved equivalent. If the disc installed pursuant to this subparagraph has a serial number specified in paragraph (a), (b), (c), or (d) of this AD, continue to inspect the disc at the interval specified in paragraph (e)(1) or (f)(1) of this AD, as appropriate.

(h) For the purpose of this AD, the number of flight cycles equals the number of flights that involve an engine operating sequence consisting of engine starting, takeoff operation, landing and engine shutdown.

This amendment becomes effective January 3, 1977.