As part of Boeing's ongoing efforts to resolve Dreamliner problems, the passenger jet maker has put out a request that airlines inspect an emergency beacon used to find aircraft in the event of a crash.
The request is based on a recommendation by the United Kingdom's Air Accidents Investigation Branch (AAIB) following a fire aboard an Ethiopian Airlines 787 Dreamliner parked at London's Heathrow Airport on July 12.
The fire caused extensive damage to the rear of the aircraft.
No one was hurt but the incident shut runways for about an hour before operations resumed, the airport said.
Randy Tinseth, vice president marketing for Boeing Commercial Airplanes, said in a statement that in addition to the 787, the company has also asked operators of 717, Next-Generation 737, 747-400, 767 and 777 airplanes to inspect aircraft.
"We're taking this action following the UK AAIB Special Bulletin, which recommended that airplane models with fixed Honeywell ELTs be inspected," he said.
"The purpose of these inspections is to gather data to support potential rule-making by regulators."
The AAIB said the emergency locator transmitter (ELT) -- which uses its own battery to send details of a plane's location in the event of a crash -- is now the focus of its investigation.
"Detailed examination of the ELT has shown some indications of disruption to the battery cells," said the AAIB bulletin.
"It is not clear however, whether the combustion in the area of the ELT was initiated by a release of energy within the batteries or by an external mechanism such as an electrical short."
'Airworthiness Directive' expected
Distancing Boeing from the malfunction, Tinseth said "it's important to note that Honeywell ELTs have been deployed on approximately 20 aircraft models -- including Boeing, Airbus and numerous business aviation aircraft."
Honeywell, the maker of the emergency beacon, said it had no knowledge of any problem with its emergency transmitter, certified by the Federal Aviation Authority since 2005.
Last week, the U.S. Federal Aviation Administration (FAA) instructed airlines operating the 787 to remove or inspect the Honeywell ELTs.
"The FAA is preparing to issue an Airworthiness Directive in the coming days that would make these inspections mandatory," said the FAA statement, released July 20. "Federal Aviation Regulations do not require large commercial aircraft in scheduled service to be equipped with these devices."
The investigations come little more than two months since the Dreamliners were allowed back in the air following a retrofit to fix an issue with its lithium-ion batteries.
Customer demand for the super-efficient airliner has remained solid despite the grounding earlier this year.
Boeing has delivered 68 of the planes to 13 airlines and has 862 unfilled orders.
It says it plans to increase production to 10 per month by the end of the year, double the rate earlier this year.
Meanwhile, Boeing is facing a possible US$2.75 million civil penalty for allegedly using certain parts in 777 construction that did not meet standards and repeatedly missing deadlines to address related quality control issues.
The FAA proposed the fine, saying Boeing's commercial aircraft division took more than two years to fully address problems after learning about quality control gaps involving fasteners in 777 construction.