Two recent uncontained failures on Pratt & Whitney PW1524-engines on SWISS Airbus A220-300s have prompted the FAA to issue an Airworthiness Directive (AD) for extra inspection of these Geared Turbofans. The AD also includes the PW-1900 as used on the Embraer E190-E2 and E195-E2. Europe’s EASA has also adopted the AD.
The first incident happened on July 25, when during a flight from Geneva to London Heathrow the number 1 engine suffered an in-flight uncontained failure. The aircraft diverted to Paris Charles de Gaulle and landed safely. On August 20, the French Bureau d’Enquetes et d’Analyses (BEA) pour la Securite de l’Aviation Civile on behalf of the NTSB called for witnesses to look out for debris that had been expelled by the stricken engine in a forest-area near Perrigny-sur-Armancon and Cry. Some parts of the Low-Pressure Compressor had been found after they had caused damage on the ground.
Part of the SWISS PW-1524G LPC Rotor 1 found in France in July. (BAE)
On September 16, an almost identical event happened to another SWISS A220-300 on a flight to Heathrow. After noticing an anomaly on engine 1 after take-off the crew returned to Geneva. On the ground, it was determined that this engine has suffered an uncontained failure as well.
These incidents follow an earlier engine failure on December 26, 2018, when a Korean Air A220-300 suffered a number 1-failure on a PW-1524G in which parts were jettisoned through the Low-Pressure Turbine.
In its AD, the FAA says that in both incidents the failure of the LPC Rotor 1 has been determined, resulting in the release of parts from the LPC. In the July-incident the PW-1524G-3 engine had done only 154 flight cycles, while the September-incident happened to a GTF with 230 flight cycles.
As a consequence, the FAA ruled on September 26 that initial and repetitive inspections of the LPC, LPC Rotor 1, and Inlet Guide Vanes are needed within 50 flight cycles or 5-7 days and the LPC replaced if damage is found. The AD covers various sub-versions of the PW-1500, which is exclusively used on the Airbus A220, and include the PW-1519, PW-1521G/GA, PW1524G/-3, and PW1525G/-3.
Similarities between PW1500 and PW1900
The AD has been extended to include the PW1900-family, with sub-versions PW1919G, PW1921G, PW1922G, and PW1923G/-A used on the Embraer E2-family. As says the AD: “Although these IFSDs occurred on PW PW1524G-3 model turbofan engines, the FAA is including PW PW1900 engines in the applicability of the AD because similarities in type design make these engines susceptible to the same unsafe condition as PW PW1500 engines”. No incidents have been reported on the E2.