The licensed aircraft engineers union, the ALAEA, is pursuing its claims that Qantas avoided a detailed safety investigation of defective offshore maintenance of a 747 last year, which could have caused some of its engines to fall off in flight.

The technical issues involved in the claims are eye-glazing in their detail, but their handling raises some questions that  federal secretary of the ALAEA Steve Purvinas wants examined by the Minister for Infrastructure and Transport, Anthony Albanese, and the Australian Transport Safety Bureau.

The ALAEA says it has correspondence that reveals how determined Qantas has been to avoid the purpose and intent of the Safety Defect Reporting or SDR system by which Australia is supposed to share relevant data with safety regulators and airlines worldwide.

Its claims come as the ATSB investigates a “serious incident” in which a Qantas 767-300 last Monday came close to landing at Sydney Airport after a flight from Melbourne with its wheels up.

The broader context is that the safety regulator, CASA, last year brushed off reports of alleged safety violations by the ALAEA against Qantas, even though it conducted a special safety audit of Qantas, which proved that it didn’t know what was going on in the airline, but discovered that Qantas standards were slipping, and refused to accept responsibility for oversight of compulsory airworthiness directives including one that Qantas had failed to finalise involving a critical modification of five Boeing 737-400s.

Those revelations followed the conduct of an audit of safety oversight in Australia by the International Civil Aviation Organisation, ICAO, which found CASA lacked in personnel with the skills, training or direction to carry out their functions.

According to the ALAEA, maintenance carried out on a Qantas 747-400 in Hong Kong left the jet with three of its four engines re-attached using single incorrectly sized and placed washers at a critical point where Qantas used two washers.

In correspondence between the ALAEA, Qantas and CASA, this is claimed to have been acceptable because the alternative for the two washers specified by Qantas is a single washer of thicker size.

(The Qantas and CASA dismissals of the significance of the ALAEA claims were reported last year, but not in detail.)

However, the ALAEA claims that the single washer instead inserted in Hong Kong was not only upside down but too thin, making the risk of engine separation in flight a significant safety threat.

The correspondence from Qantas, which has been seen by Crikey, could be summarised fairly as saying Qantas will decide what is or is not a safety threat, and that it had informally notified CASA, a process that the union says defeated the purpose and intent of the formal safety defect reporting system.

This goes to the heart of the CASA/QANTAS relationship. Should it be rigorously “formal”, or “informal” in all respects?

The question remains, will the government act to break the corporate capture of CASA by Qantas before there is a serious accident, or after one?