AD 2012-04-04

final rule
Data completeness: 70%

Airworthiness Directives; Pratt & Whitney Division Turbofan Engines

AD Number
2012-04-04
Status
final_rule
Effective Date
Product Category
engine
Docket
Docket No. FAA-2011-0944
FR Citation
77 FR 12448

Applicability

TypeManufacturerModelDetails
engine Pratt & Whitney Division Airworthiness Directives; Pratt & Whitney Division Turbofan Engines

Unsafe Condition

Engine overspeed event during taxi resulted in a high-pressure compressor surge and tailpipe fire, prompting the need to address the design of the fuel metering units (FMUs).

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Replace Pratt & Whitney fuel metering units (FMUs), part numbers 53T335 (HS 801000-1), 55T423 (HS 801000-2), and 50U150 (HS 801000-3), at the next shop visit after the effective date of the AD.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

At the next shop visit after the effective date of the AD.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Pratt & Whitney PW4050, PW4052, PW4056, PW4060, PW4060A, PW4060C, PW4062, PW4062A, PW4152, PW4156, PW4156A, PW4158, PW4160, PW4460, PW4462, and PW4650 turbofan engines, including models with any dash number suffix.

AI-generated summary from the source AD text. Verify against the official source before acting.

Source: Official FAA Source ↗

Retrieved: Apr 6, 2026

Rights: U.S. Government Public Domain

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