The Federal Aviation Administration has ordered airlines to replace disks in some Pratt & Whitney PW1100G turbofans, saying the powerplants could have the same problem that caused the 2020 uncontained failure of an International Aero Engines (IAE) V2500.
The components of concern are high-pressure turbine (HPT) first- and second-stage disks. P&W is among several companies that produce IAE engine components as part of a consortium.
“The FAA considers removal of certain HPT first-stage and HPT second-stage disks to be an urgent safety issue,” the agency says in an 8 September airworthiness directive (AD). “These HPT disks have the highest risk of failure and require removal within 30 days… This unsafe condition may result in loss of the airplane.”
The FAA took action after learning that some PW1100G HPT disks are made from a material “similar” to that used to produce disks in a V2500 that failed on 18 March 2020.
That V2500 “experienced an uncontained HPT first-stage disk failure that resulted in high-energy debris penetrating the engine cowling”, FAA documents say. “Pratt & Whitney determined that the failure… was due to an undetected subsurface material defect in an HPT disk.”
Following that incident, P&W reviewed “all other IAE and P&W engines that contain parts of similar material”, the FAA says. The analysis showed that some PW1100Gs “are also affected by the unsafe condition”.
The new AD takes effect in 15 days and applies only to 10 PW1100G variants, of which only three are installed on US-registered aircraft. It requires US operators to replace affected PW1100G HPT first- and second-stage disks within 30 days of the effective date.
Neither the FAA nor P&W responded immediately to questions about the issue, including about how many A320neo-family jets globally might have engines with the potential defect.
FAA documents have not named the airline that operated the A321 involved in the 18 March 2020 incident. However, on that date a Vietnam Airlines A321 powered by V2500s aborted take-off with apparent damage to one engine.
The FAA responded to that event with several ADs that required airlines to inspect and replace HPT disks in some V2500s. P&W co-owns IAE as part of a consortium including MTU Aero Engines and Japanese Aero Engines.
Update on 9 September: Globally, the condition affects 55 PW1100Gs worldwide, the FAA tells FlightGlobal.