If you are going to have a fire on an airliner at cruising altitude, having it right beside the first officer who is already waiting with a fire extinguisher is the best place for it.

This in short is what happening in the early hours this morning on a Jetstar A330-200 with a total of 199 people on board flying from Osaka to the Gold Coast.

The electrical source of the fire was disconnected and it was put out, the smoke cleared from the cockpit and the jet diverted to Guam, the nearest suitable airport, where it will soon be swarmed over by Qantas maintenance and systems people and investigators from the ATSB, all en route on a replacement A330 which will bring the passengers to Brisbane, not the Gold Coast, much later tonight.

Fires in aircraft are always serious. Really serious if they break out in the cargo or baggage holds, where elaborate fire suppression systems are found on all jets. Even a trace of smoke on the detectors will cause an immediate landing at the first possible airport. Or in extremis, a deliberate crash landing. Once fire takes hold a jet has only minutes left.

Jetstar flight JQ20 was not in extremis or anywhere near it. The fact that it was the same type of jet that crashed in the mid Atlantic on 1 June, killing all 228 people on an Air France flight between Rio de Janeiro and Paris means nothing, apart from shallow fear button pushing coverage in the Fairfax media this morning:

A Jetstar source says the pilots had prior warning of the incident from an electrical malfunction indication and almost at the same moment, a burning odour. It was internally described as a textbook incident and diversion. However it hadn’t been established if any damage was done to the jet’s avionics, there was no mention of any issues in flying the diversion to Guam or the landing.

The last burning window heater incident on a large Australian jet involved a Qantas 747-300 (now retired from service) on the final stage of a flight from Perth to Sydney 16 months ago.

The summary of the ATSB report into that incident says:

On 25 February 2008, at about 2128 Eastern Daylight-saving Time, the flight crew of a Boeing Company 747-338 (747) aircraft, registered VH-EBY, detected a smell that slowly increased in intensity. At that time, the aircraft was cruising at 37,000 ft and was about 275 km west south-west of Sydney, NSW.

The flight crew donned their emergency oxygen equipment and transmitted a PAN call to air traffic control. The aircraft was cleared direct to Sydney for landing and was escorted to the terminal by the airport fire services for disembarkation.

An inspection by the operator determined that loose terminal connections to the left windshield heat element resulted in electrical arcing and fumes on the flight deck.

The aircraft manufacturer has a programme to replace the windshields in the 747 with an enhanced windshield heater wiring connection that should address the risk of electrical arcing in that component.