Airworthiness Directive · Amendment 39-16970 · Rolls-Royce plc Turbofan Engines
Rolls-Royce plc Turbofan Engines
This AD applies to Rolls-Royce plc (RR) RB211-Trent 800 turbofan engines, all models, all serial numbers.
We are adopting a new airworthiness directive (AD) for RB211- Trent 800 series turbofan engines. This AD requires inspecting the front combustion liner head section for cracking, and if found cracked, removing the front combustion liner head section from service at the next shop visit. This AD was prompted by mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. Specifically, routine inspections revealed cracking on the head sections of two RB211-Trent 800 front combustion liners. We are issuing this AD to prevent uncontained engine failure and damage to the airplane.
Unless already done, do the following actions.
(1) Within 1,000 flight cycles (FCs) after the effective date of this AD, inspect the front combustion liner head section for cracking. Use paragraph 3.A.(1), except for 3.A.(1)(a)(i), or paragraphs 3.A.(2)(b) through 3.A.(2)(d) of the On-Wing Accomplishment Instructions of RR Alert Service Bulletin (ASB) No. RB.211-72-AG456, Revision 1, dated November 4, 2011, to do your inspections.
(2) If you find cracking, remove the front combustion liner head section from service at the next shop visit. Until the next shop visit, take the corrective actions listed in Table 1 of this AD, as applicable.
| Inspection findings | Action(s) and compliance time(s) |
|---|---|
| (i) Cumulative crack length up to 150 mm (up to 2 heatshields) | Reduce the inspection intervals to 250 FCs. |
| (ii) Cumulative crack length 150 mm to 300 mm (up to 4 heatshields) | Reduce the inspection intervals to 100 FCs. |
| (iii) Cumulative crack length 300 mm to 450 mm (up to 6 heatshields) | Remove the engine within 50 FCs. |
| (iv) Cumulative crack length 450 mm to 900 mm (up to 12 heatshields) | Remove the engine within 5 FCs. |
| (v) Cumulative crack length greater than 900 mm (more than 12 heatshields) | Remove the engine before next flight. |
(1) Within 1,000 FCs after the effective date of this AD, inspect the front combustion liner head section for cracking. Use paragraph 3.A.(1), except for 3.A.(1)(a)(i), or paragraphs 3.A.(2)(b) through 3.A.(2)(d) of the On-Wing Accomplishment Instructions of RR ASB No. RB.211-72-AG456, Revision 1, dated November 4, 2011, to do your inspections.
(2) If you find cracking, remove the front combustion liner head section at the next shop visit. Until the next shop visit, take the corrective actions as detailed in Table 1 of this AD, as applicable.
(3) For engines not found to have cracks in the front combustion liner head section in accordance with paragraphs (f)(1) or (g)(1) of this AD, at every shop visit after the effective date of this AD:
(i) Fluorescent-penetrant inspect the front combustion liner head section for cracking; or
(ii) Borescope-inspect the front combustion liner head section for cracking. Use paragraph 3.B.(1)(b) except paragraph 3.B.(1)(b)(i), or use paragraphs 3.B.(2)(b) through 3.B.(2)(d), of the In-shop Accomplishment Instructions of RR ASB No. RB.211-72-AG456, Revision 1, dated November 4, 2011.
(iii) If any cracks are found, reject the front combustion liner.
(4) Accomplishment of a shop visit inspection as required by paragraph (g)(3) of this AD may substitute for the accomplishment of an on-wing inspection as required by paragraph (f)(1) or (g)(1) of this AD.
For the purpose of this AD, the term shop visit means the induction of an engine into the shop for maintenance where the front combustion liner is exposed, or when the 04 module has been removed from the engine, or when the engine has been removed from service as a result of paragraph (f)(2) or (g)(2) of this AD.
An initial or repetitive inspection performed before the effective date of this AD using RR ASB No. RB.211-72-AG456, dated September 9, 2010, satisfies the initial inspection requirement in paragraph (f) or repetitive inspection requirement in paragraph (g) of this AD.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Engines
