The United States airlines using General Electric Co GEnx jet engines will be required to inspect their planes for signs of the type of flaws that led to a July explosion, the Federal Aviation Administration said.

Atlas Air Worldwide Holdings Inc, the only carrier flying the Boeing Co jets with those engines, found nothing wrong on one of its 747-8 freighters on Friday and was inspecting the other aircraft, the FAA said in an e-mailed statement. A formal directive is being prepared, the FAA said.

The FAA plan heightened the scrutiny on the GEnx since a Boeing 787 Dreamliner spewed hot metal engine parts during a July 28 test in Charleston, South Carolina. There have now been three instances of damage to GEnx engines, which are used only on Boeing's two newest planes, the 787 and the 747-8 jumbo jets.

"This now has entered the phase where it's incumbent on GE and Boeing to come up very quickly with a very clear answer as to what the fix is, or they're going to be hurting very badly," Hans Weber, chief executive officer of aviation consultant Tecop International Inc, said in a telephone interview. "They're now under real pressure."

The FAA's inspection directive followed a recommendation for the check from the US National Transportation Safety Board, which investigates aviation accidents. Regulators worldwide typically follow the FAA's lead in such cases.

"Because of the immediate threat of multiple engine failures on a single aircraft and the availability of an appropriate inspection procedure, there is an urgent need for the FAA to act immediately," the NTSB wrote in a letter to the agency.

Hours later, the FAA said it "will continue to review the recommendations and coordinate closely with the NTSB and GE as part of the investigation".

A similar GEnx engine crack was found last month on a twin-engine Dreamliner that hadn't flown yet, according to the NTSB. A four-engine 747-8 flown by a Russian cargo carrier suffered an engine failure on Sept 11 in China, and preliminary evidence shows it may have failed the same way as in Charleston, according to the NTSB.

(China Daily 09/17/2012 page14)