It now appears that all the speculation surrounding the return of a Qantas plane an hour into journey from Sydney to LA on Tuesday was either hasty or wrong. The airline claims a thorough inspection turned up no significant damage. Today’s Age reports:

Qantas spokesman Lloyd Quartermaine said the aircraft had been “thoroughly inspected” but there was no evidence of any structural damage to the plane, and it had been returned to service.

Qantas said the huge cracks discovered on the plane three years ago had been fixed.

“We worked closely with Boeing on the earlier issue with this aircraft and it has been fully rectified,” Qantas’s head of engineering, David Cox, said.

A Civil Aviation Safety Authority spokesman, Peter Gibson, said the incident had been reported to the regulator but a safety inspection had not found any faults.

For those within the industry, there appeared to be more to the story. Crikey received this response yesterday from an aviation industry insider:

Were it not for the observant eyes of a flight attendant, who at one point on the ground when the door was open, noticed the dull, opaque glow of daylight shining through the paint which was covering a crack, the plane would have likely continued to fly. This would have been fine – for two or three more flights – but beyond that, Qantas’s reputation for safety [would] almost [certainly] have suffered a pretty serious and emphatic setback.

Fracture mechanics can predict the rate of crack growth with some certainty based on known conditions, like stress, temperature and material characteristics etc. All aircraft – even new ones – have cracks in them. Cracks below a certain length (called “sub-critical”) are deemed safe and in fact sometimes do not even grow. The cracks on the “ugly sister” aircraft had been growing however, and based on estimations would have reached critical length in a couple of flights – beyond which the rate of crack growth increases rapidly, known as “catastrophic failure”. To a layman, this is the point where things “break” or “snap”. Obviously, aeroplanes snapping is not a good look.

By this morning, PPRUNE posters had also corrected themselves, though we are unable to bring you any details. In an intriguing twist, yesterday’s Crikey story had been quoted in the original thread but that thread has now been removed from the site.

Crikey contacted the site’s administrators for an explanation but received no response by publication time.