Airworthiness Directive · Amendment 39-16885 · Pratt & Whitney Division (PW) PW4000 Series Turbofan Engines
Pratt & Whitney Division (PW) PW4000 Series Turbofan Engines
This AD applies to the following Pratt & Whitney Division (PW) turbofan engines, with high-pressure turbine (HPT) stage 1 airseal, part number (P/N) 50L879; HPT stage 2 airseal, P/N 53L030; or HPT stage 1 airseal ring, P/N 50L664, installed:
We are adopting a new airworthiness directive (AD) for certain PW4000 turbofan engines. This AD was prompted by an updated low-cycle fatigue (LCF) life analysis performed by PW. This AD requires removing certain part number (P/N) high-pressure turbine (HPT) stage 1 and HPT stage 2 airseals and HPT stage 1 airseal rings before their published life limit and establishes a new lower life limit for these parts. We are issuing this AD to prevent failure of these parts, which could lead to an uncontained engine failure and damage to the airplane.
Remove the stage 1 HPT airseal, P/N 50L879, at the next piece-part exposure after the effective date of this AD or before accumulating the number of cycles listed in Table 1 of this AD, whichever occurs later.
| For engine model... | Remove stage 1 HPT airseal by... |
|---|---|
| (1) Listed in paragraph (c)(1) of the Applicability Section of this AD | 12,600 CSN. |
| (2) Listed in paragraph (c)(2)(i) of the Applicability Section of this AD | 13,900 CSN. |
| (3) Listed in paragraph (c)(2)(ii) of the Applicability Section of this AD | 18,900 CSN. |
Remove the stage 2 HPT airseal, P/N 53L030, at the next piece-part exposure after the effective date of this AD or before accumulating the number of cycles listed in Table 2 of this AD, whichever occurs later.
| For engine model... | Remove stage 2 HPT airseal by... |
|---|---|
| (1) Listed in paragraph (c)(1) of the Applicability Section of this AD | 13,900 CSN. |
| (2) Listed in paragraph (c)(2)(i) of the Applicability Section of this AD | 13,800 CSN. |
| (3) Listed in paragraph (c)(2)(ii) of the Applicability Section of this AD | 15,900 CSN. |
Remove the stage 1 HPT airseal ring, P/N 50L664, at the next piece-part exposure after the effective date of this AD or before accumulating the number of cycles listed in Table 3 of this AD, whichever occurs later.
| For engine model... | Remove stage 1 HPT airseal ring by * * * |
|---|---|
| (1) Listed in paragraph (c)(2)(i) of the Applicability Section of this AD | 14,800 CSN. |
| (2) Listed in paragraph (c)(2)(ii) of the Applicability Section of this AD | 16,800 CSN. |
After the effective date of this AD, do not install any stage 1 HPT airseal, P/N 50L879, stage 2 HPT airseal, P/N 53L030, or stage 1 HPT airseal ring, P/N 50L664, that is at piece-part exposure and exceeds the new life limit listed in Table 1, Table 2, or Table 3 of this AD.
For the purpose of this AD, piece-part exposure means that the part is completely disassembled and removed from the engine.
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.
