Safety regulators are requiring inspections of Boeing 787 planes following an issue with the engine anti-ice system, according to an airworthiness directive published Tuesday.
The directive from the Federal Aviation Administration, requiring new inspections after discovering a possible safety concern on Boeing planes, is the third such command Boeing has received in just two days.
On Monday, Boeing grounded its 777X test fleet after discovering damage to a structural part that connects the engine to the rest of the plane. The FAA had recently cleared Boeing to begin test flights for the 777X fleet, after certification has repeatedly been delayed. Now, those test flights are back on hold.
Earlier on Tuesday, the FAA said it would require another set of inspections on Boeing 787 Dreamliners, this time focused on cockpit seats. That directive came after a plane went into a nose-dive because the captain’s seat lurched forward without warning and disconnected the plane’s autopilot system. Several dozen passengers were injured on the March flight.
The engine anti-ice system airworthiness directive, which takes effect in September, will impact all of Boeing’s 787-8, 787-9 and 787-10 planes. The FAA estimates that will total 110 jets registered in the U.S.
Boeing said Tuesday it supports the FAA’s actions. “The in-service fleet can continue to safely operate,” a spokesperson said. “We are working closely with our customers to help mitigate any potential impacts.”
The directive follows guidance Boeing provided to 787 operators in September and a notice of proposed rulemaking the FAA issued about the engine anti-ice system in February. That notice was prompted by a report of heat damage on multiple engine inlets around the engine anti-ice duct.
The FAA found in a subsequent investigation that the seals between the inner and outer ducts, and between the outer duct and the aft compartment, were degraded or missing. That meant the engine anti-ice system was leaking air into the aft compartment and exposing inlet components to high temperatures.
The airworthiness directive issued Tuesday is meant to address “reduced structural strength and departure of the inlet from the airplane,” the FAA wrote. If the inlet did leave the plane, it could hit the jet’s wing, tail or fuselage.
It was exactly such an accident in 2018 that produced the single major U.S. airline passenger fatality in the last 15 years, when an engine inlet broke off on a Southwest Airlines 737 en route from New York to Dallas and struck the fuselage.
The airworthiness directive comes after the FAA found a separate problem with the same system on Boeing’s 737 Max plane. In that case, the FAA said, a design flaw could theoretically disable the jet’s engine anti-ice system.
On the Max, Boeing identified a potential single point of failure that could result in the loss of the anti-ice systems on both engines, with no indication or warning that would alert the pilots.
Boeing and the FAA said the issue on the Max plane had not been seen in service.
The issue on the 787, however, has resulted in damage to engines on passenger aircraft, according to the FAA’s proposed rulemaking from February.
Boeing issued a service bulletin to 787 operators months earlier, in September, informing them of the issue and recommending inspection of the inlet cowl assembly on both engines of every 787 for signs of heat damage around the engine anti-ice duct.
The FAA airworthiness directive issued Tuesday will make those instructions mandatory. It also requires operators to do a records check and update its minimum equipment list, or MEL.
The FAA expects it will take roughly five hours to perform the records check and update the equipment list, and another three hours to inspect the engine.
In a comment period between the notice of proposed rulemaking and the airworthiness directive being issued, British Airways asked the FAA for an additional 125 days to perform the inspections and make any fixes in order to avoid any disruptions to its service.
The FAA on Tuesday declined to do so because it expected the “potential structural damage” could increase as each engine inlet spends more time in operation.
