The Ministry of Land, Infrastructure, Transport, and Tourism of Japan announced on March 18, 2022, that the suspension of operations for Boeing 777 aircraft equipped with Pratt & Whitney PW4000 engines had been lifted.
The aircraft were forbidden from operating in Japan since February 2021, in response to a series of incidents.
On December 2, 2020, a Japan Airlines Boeing 777 was affected by an uncontained failure of its PW4000 engine during a domestic flight. On February 20, 2021, a United Airlines Boeing 777-200, flying from Denver, United States to Honolulu, Hawaii, US, suffered a similar issue, scattering engine parts over several neighborhoods around Denver.
This second incident prompted Boeing to request the almost immediate grounding of 128 aircraft around the world. Along with the United States, South Korea, and the United Kingdom, Japan ordered a complete suspension of operations in the country for the affected model, both for Japanese and foreign carriers.
Japan Airlines (JAL) and All Nippon Airways (ANA) grounded 13 and 19 aircraft, respectively. In April 2021, JAL announced it would retire its 24 Boeing 777s in the -200 and -300 series by 2023 and replace them with the A350.
Upon preliminary examination of the United Airlines Boeing 777-200, the NTSB found that two fan blades were fractured in the right-hand Pratt & Whitney PW4077 engine. One fan blade was fractured near the root, while an adjacent fan blade was fractured about mid-span. The damage appeared consistent with metallic wear.
On March 11, 2022, the US Federal Aviation Administration (FAA) ordered corrective measures to be taken on PW4000 engines in three airworthiness directives. These included the structural reinforcement of the engine inlet to withstand fan blade failures, as well as repetitive ultrasonic and thermal acoustic image inspections for cracks on fan blades.
The measures were seemingly satisfactory for Japan’s Ministry of Transport, which lifted the ban on March 18, 2022.
“Now that 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,” the Ministry said in a statement.
According to planespotters.net data, ANA still operates 14 PW4000-powered Boeing 777s, out of which ten -200 and four -300 series, while JAL only flies five Boeing 777-200s.