Regulatory action mandated by international civil aviation authorities after the 20 February failure of a Pratt & Whitney PW4000 on a United Airlines Boeing 777 affect a relatively small proportion of the 777 fleet.
Cirium fleet data shows that 1,104 777s were in service on 19 February, while 435 were listed as being in storage. Of the 1,539 aircraft, 1,076 (or 70%) belong to the widebody family’s second generation – 777-300ERs, -200LRs and Freighters – exclusively powered by GE Aviation GE90-115B/110B engines.
PW4000-112 engines equip 127 earlier-generation 777-200s and -300s – 60 in service and 67 in storage. The remaining aircraft are equipped with Rolls-Royce Trent 800s (185 aircraft) or earlier-generation GE90 engines (151).
The US Federal Aviation Administration (FAA) has ordered emergency inspections of PW4000-112s, while regulators in Japan and the UK have banned operation of 777s with that engine. All in-service aircraft in that sub-fleet are based in the USA, Japan or South Korea.
United is the largest operator of PW4000-powered 777s, with a fleet of 52 777-200s – 22 in service and 30 in storage – built between 1995 and 2002. The aircraft affected by the engine failure (N772UA) is a 1995-vintage 777 equipped with PW4077 engines.
The US carrier is still able to operate its 44 GE90-powered 777s.
The second-largest operator of PW4000-powered 777s is All Nippon Airways, which says it has 19 such aircraft. The Japanese carrier’s fleet also includes 26 GE90-powered 777-300ERs and two 777 freighters.
Korean Air has 16 PW4000-powered 777s – seven in service and nine stored – while its low-cost sibling Jin Air operates four. Again, the majority of Korean’s 777 fleet is comprised of 26 777-300ERs and 12 777Fs, all of which are listed as being in service.
Asiana Airlines, which is to be acquired by Korean under an agreement disclosed in November, has nine PW4000-powered 777s, including two in storage.
Japan Airlines has nine in-service and four stored 777s with PW4000s. It also has 24 GE90-powered 777s, four of which are listed as being in storage.
EgyptAir has four PW4000-powered 777s in storage, and several further airlines and other parties have single-digit numbers of the aircraft in storage.
Earlier PW4000-94 variants were employed on 747s, 767s, MD-11s, Airbus A300 and A310s, while the 100in-fan-diameter PW4000 is on option on A330s.
Cirium fleets data shows that 122 in-service and 72 stored A330s are equipped with PW4000 engines. The youngest aircraft in that fleet was built in 2017 and is operated China Southern Airlines.
When Cirium contacted Airbus about the possibility of additional inspections being required for PW4000-equipped A330s as a result the United 777 incident, the European airframer cited FAA communications that action is currently limited to the powerplant’s 112in-fan-diameter series exclusively used on 777.
Pratt & Whitney confirms that the FAA’s airworthiness directive requiring fan blade inspections applies only to PW4000-112 engines.
Updated with information provided by ANA and P&W
The second-largest operator of PW4000-powered 777s is All Nippon Airways, which says it has 19 such aircraft. The Japanese carrier’s fleet also includes 26 GE90-powered 777-300ERs and two 777 freighters.
