Transmitter suspected as cause of Dreamliner fire that brought Heathrow to a halt An emergency locator transmitter problem may have caused the fire on a Boeing 787 Dreamliner plane that caused disruption last week at Heathrow airport, it was revealed today. UK accident investigators said that US aerospace part manufacturer Honeywell had been invited to join their probe into last Friday's incident aboard a parked, empty Ethiopian Airlines' Dreamliner at Heathrow. Honeywell built the emergency locator transmitter and there is speculation that the transmitter's battery caused the fire. Another different battery problems led to Dreamliners being grounded for a time earlier this year. Earlier this week the UK's Air Accidents Investigation Branch (AAIB) which is looking into the Heathrow incident, said there was "no evidence of a direct causal relationship" between the batteries and the Heathrow fire. Today the AAIB said: "We can confirm that Honeywell have been invited to join the investigation. The emergency locator transmitter is one of several components being looked at in detail as part of the investigation and it would be premature to speculate on the causes of the incident at this stage. The travelling public can be sure we are investigating all possible causes and following up all leads. The battery problem earlier this year led to delivery delays which caused Thomson Airways to scrap plans to use the ultra-green aircraft in May and June. The carrier finally begun Dreamliner services earlier this month. Continuous production difficulties had already plagued the Dreamliner. It should have entered passenger service in 2008 but it was not until October 2011 that the first commercial flight was operated by Japanese carrier All Nippon Airways. British Airways has taken delivery of the first of its 24 Dreamliners, while Virgin Atlantic is due to receive the first of its 16 Dreamliners in September next year.