Japan has lifted an operating ban on all Pratt & Whitney PW4000-powered Boeing 777s, more than a year after it was imposed following a serious engine failure on a US aircraft. 

The Japan Civil Aviation Bureau first imposed the restriction on 22 February 2021, stating then that suspension will remain in force “until necessary measures are formulated”. 


Source: Wikimedia Commons

Two days before the ban, a United Airlines 777-200 (registration N772UA) flying from Denver to Honolulu suffered a major failure after taking off, shedding debris over a residential area, including the engine’s nose cowl that landed feet from a house. 

It followed a similar incident that occured on a Japan Airlines 777-200 in December 2020, when the PW4000 engine suffered a significant failure. The incident occurred as the aircraft, JA8978 (MSN 27637), operated flight JL904 from Okinawa’s Naha airport to Tokyo Haneda. 

A statement from Japan’s Ministry of Land, Infrastructure, Transport and Tourism on 18 March says: “The technical evaluation has been completed, and the validity of the recurrence prevention measures has been confirmed. [We] will permit the resumption of commercial operation of the aircraft, on condition that the recurrence prevention measures are implemented.” 

Since the grounding, Japan’s two largest carriers - Japan Airlines and All Nippon Airways - have retired a large number of PW4000-powered 777s, citing a lack of timeline in lifting the ban, as well as the need for fleet rationalisation amid a pandemic-driven downturn. 

According to Cirium fleets data, there are 53 PW4000-powered 777s in storage, with none in service. Another 33 examples have been retired.