WASHINGTON (US) – The Federal Aviation Administration (FAA) has ordered the immediate inspection of Boeing 777 aircraft with Pratt & Whitney PW4000 engines in the wake of an engine failure on a United flight on Saturday.
The FAA said operators must undertake a thermal acoustic image inspection of the titanium fan blades in front of each engine.
On Monday, the National Transportation Safety Board said a cracked fan blade from the United Flight 328 that caught fire was consistent with metal fatigue.
“Based on the initial results as we receive them, as well as other data gained from the ongoing investigation, the FAA may revise this directive to set a new interval for this inspection or subsequent ones,” the FAA said.
The 26-year-old Boeing 777, which developed engine failure and shed parts over a Denver suburb on Saturday, had a PW4000. As many as 128 aircraft have those engines.
The FAA ordered inspections every 6,500 cycles in March 2019 following a United engine failure the previous year. A cycle comprises one take-off and landing.
The transport ministry of South Korea said on Tuesday it had directed its airlines to inspect fan blades every 1,000 cycles following guidance from Pratt.
Every 10 months, a 777 airline accumulates 1,000 cycles.
In 2019, the FAA said that each inspection would take 22 man hours and cost $1,870.
According to Pratt, which is owned by Raytheon Technologies, fan blades have to be shipped to its repair facility in East Hartford, Connecticut, for fresh inspections.
Boeing announced its willingness to comply with the FAA’s latest inspection guidance and pledged to work through the process with customers.
On Wednesday, the Japanese transport ministry said it was examining the FAA directive and had not decided the next course of action.