FAA Airworthiness Directive for Certain Pratt & Whitney PW4000 Engines
AI-generated summary for informational purposes only. Not legal advice. See the original source for the authoritative text.
The rule requires airlines and maintenance operators to repeatedly inspect certain Pratt & Whitney PW4000-series engines for cracks in key compressor and turbine parts. If inspections find crack signs, the affected parts must be removed and replaced. Some listed engine serial numbers also require replacement of a specific high-pressure turbine air seal. The FAA is acting after a related engine failure involving a separated rotor during takeoff, which led to an aborted takeoff. Operators using the covered engines need to update maintenance schedules, follow the referenced Pratt & Whitney service instructions, and complete required inspections and replacements from June 26, 2026.
AI-generated summary. May contain errors. Refer to official sources for legal decisions.
Key Changes
- Requires repeated ultrasonic inspections of specified compressor and turbine components in covered Pratt & Whitney PW4000 engines
- Requires removal and replacement of parts if crack indications are found
- Requires replacement of the high-pressure turbine 1st-stage air seal for certain engine serial numbers
Obligations
What this law requires
Perform repetitive angle ultrasonic scan inspections of affected Pratt & Whitney PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 engines' HPC 15th-stage disks for crack indications in accordance with the incorporated Pratt & Whitney service instructions.
Perform repetitive angle ultrasonic scan inspections of affected engines' front turbine hubs for crack indications in accordance with the incorporated Pratt & Whitney service instructions.
Perform repetitive angle ultrasonic scan inspections of affected engines' HPT 1st-stage air seals for crack indications in accordance with the incorporated Pratt & Whitney service instructions.
Perform repetitive angle ultrasonic scan inspections of affected engines' HPT 2nd-stage hubs for crack indications in accordance with the incorporated Pratt & Whitney service instructions.
Remove from service and replace any HPC 15th-stage disk, front turbine hub, HPT 1st-stage air seal, or HPT 2nd-stage hub if the required angle ultrasonic scan inspection identifies crack indications.