Clouds of black smoke billowed from a British Airways Boeing 777 on a Las Vegas runway last week after its pilots aborted a flight only moments before takeoff.

The cause for grounding: Engine failure.

Turns out the Federal Aviation Administration had alerted airplane makers to the engine’s potential problems in a 2011 safety warning, reports the Daily Beast. The regulators issued a so-called airworthiness directive pertinent to the device in question—a GE90-85B turbofan engine made by General Electric —after discovering cracks in a weld joint.

“The unsafe condition could result,” notes the directive, in “uncontained engine failure and damage to the airplane.”

Two companies, GE and Boeing, initially petitioned the FAA to remove the “unsafe condition” paragraph—but to no avail. “[B]y their analyses, cracks in the weld joint would not develop into into an uncontained failure,” the directive states. “We do not agree.”

The regulators ruled that the products must undergo “mandatory repetitive inspections.” Airlines would have to check up on the engines after 48,000 hours of use or 6,000 flights.

“One thing that investigators will now have to consider,” notes Daily Beast reporter Clive Irving, “is whether the intervals between inspections mandated by the FAA were too long and that a crack appeared in the compressor and went undetected.”

“British Airways complies with all Airworthiness Directives,” a spokesperson for the airline told Fortune in an email. “We will not be commenting any further while the NTSB [National Transportation Safety Board] investigation is active.”

GE and Boeing were not immediately available for comment.

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