Airworthiness Directive · Amendment 39-16845 · Rolls-Royce Corporation Turbofan Engines
Rolls-Royce Corporation Turbofan Engines
This AD applies to Rolls-Royce Corporation (RRC) AE 3007A, AE 3007A1/1, AE 3007A1, AE 3007A1/3, AE 3007A1E, AE 3007A1P, and AE 3007A3 turbofan engines, with any of the 6th-through-13th stage compressor wheel part numbers (P/Ns) in Table 1 of this AD installed.
| Compressor wheel stage | Wheel P/Ns with chrome-carbide coated knife seals | Wheel P/Ns with uncoated knife seals |
|---|---|---|
| 6th | 23074717 | 23062666, 23071261, 23071396 |
| 7th | 23074719, 23074217 | 23062667, 23071262, 23071397 |
| 8th | 23074721 | 23061628, 23071263 |
| 9th | 23074722 | 23061629, 23071264 |
| 10th | 23074723 | 23061630, 23071265 |
| 11th | 23074724 | 23061631, 23066231 |
| 12th | 23074725 | 23061632, 23071267 |
| 13th | 23074213, 23074726 | 23061633, 23071268 |
We are adopting a new airworthiness directive (AD) for Rolls- Royce Corporation (RRC) AE 3007A, AE 3007A1/1, AE 3007A1, AE 3007A1/3, AE 3007A1E, AE 3007A1P, and AE 3007A3 turbofan engines. This AD requires initial and repetitive eddy current inspections (ECI) of certain 6th-through-13th stage compressor wheel knife edge seals, and initial and repetitive ECIs of the compressor wheel outer circumference, for cracks. This AD was prompted by reports of low-cycle fatigue cracks found during shop visits, in the 6th-through-13th stage compressor wheels having chrome-carbide coated or uncoated knife edge seals. We are issuing this AD to prevent uncontained failure of the 6th-through-13th stage compressor wheel, leading to damage to the airplane.
The initial inspection compliance times for the 6th-through-13th stage compressor wheels are based on cycles-since-new (CSN) and cycles-in-service (CIS) of their 12th and 13th stage compressor wheels. For engines that one or both 12th and 13th stage compressor wheels have chrome-carbide coated knife edge seals, use the compliance times listed in Table 2 of this AD. For engines that both 12th and 13th stage compressor wheels do not have chrome-carbide coated knife edge seals, use the compliance times listed in Table 3 of this AD.
(1) Perform a one-time comprehensive eddy current inspection (ECI) of the 6th-through-13th stage compressor wheel knife edge seals for cracks, using paragraph 2, Accomplishment Instructions, of RRC Alert Service Bulletin (ASB) No. AE 3007A-A-72-386, Revision 4, dated June 27, 2011 (Completion of this one-time comprehensive ECI relieves you thereafter of the repetitive inspection requirements of this AD); or
(2) Perform an initial ECI of the 6th-through-13th stage compressor wheel outer circumferences for cracks, using paragraph 2, Accomplishment Instructions, of RRC ASB No. AE 3007A-A-72-390, Revision 3, dated June 27, 2011.
| For 12th and or 13th stage compressor wheels with the following CSN on the effective date of this AD | Initially inspect after the effective date of this AD |
|---|---|
| (i) 18,185 or more CSN | Within 15 CIS. |
| (ii) 16,700 to 18,184 CSN | Before accumulating 18,200 CSN. |
| (iii) 16,000 to 16,699 CSN | Within 1,500 CIS. |
| (iv) 15,100 to 15,999 CSN | Within 2,000 CIS. |
| (v) 14,300 to 15,099 CSN | Within 2,800 CIS. |
| (vi) 13,000 to 14,299 CSN | Within 3,400 CIS. |
| (vii) 12,300 to 12,999 CSN | Within 4,000 CIS. |
| (viii) 11,200 to 12,299 CSN | Within 4,600 CIS. |
| (ix) 9,700 to 11,199 CSN | Within 5,300 CIS. |
| (x) Fewer than 9,700 CSN | Before accumulating 15,000 CSN or at the next shop visit when the engine has more than 7,000 cycles, whichever occurs first. |
| For 12th and or 13th stage compressor wheels with the following CSN on the effective date of this AD: | Initially inspect after the effective date of this AD: |
|---|---|
| (i) 18,300 or more CSN | Within 200 CIS. |
| (ii) 16,000 to 18,299 CSN | Within 1,500 CIS. |
| (iii) 15,100 to 15,999 CSN | Within 2,000 CIS. |
| (iv) 14,300 to 15,099 CSN | Within 2,800 CIS. |
| (v) 13,000 to 14,299 CSN | Within 3,400 CIS. |
| (vi) 12,300 to 12,999 CSN | Within 4,000 CIS. |
| (vii) 11,200 to 12,299 CSN | Within 4,600 CIS. |
| (viii) 9,700 to 11,199 CSN | Within 5,300 CIS. |
| (ix) Fewer than 9,700 CSN | Before accumulating 15,000 CSN or at the next shop visit when the engine has more than 7,000 cycles, whichever occurs first. |
(1) After passing the initial inspection, perform repetitive ECIs of the compressor wheel outer circumference, for cracks, within every 5,000 cycles-since-last-inspection (CSLI), using paragraph 2, Accomplishment Instructions, of RRC ASB No. AE 3007A-A-72-390, Revision 3, dated June 27, 2011; or
(2) Perform a one-time comprehensive ECI of the 6th-through-13th stage compressor wheel knife edge seals for cracks, within 5,000 CSLI using paragraph 2, Accomplishment Instructions, of RRC ASB No. AE 3007A-A-72-386, Revision 4, dated June 27, 2011. Completion of this one-time ECI comprehensive inspection relieves you thereafter of the repetitive inspection requirements of this AD.
Remove from service before further flight 6th-through-13th stage compressor wheels that are found cracked.
