Forgotten cleaning rag a risk to Qantas jet

Photo / Getty Images

A cleaning rag left behind during maintenance of a Qantas Boeing 737 was found trapped inside a cable drum during a routine inspection at Auckland Airport.

The rag had caused some damage and compromised the plane's stabiliser trim system manual control, a report into the incident found.

It was one of two incidents within a year where rags were left inside Qantas aircraft following maintenance.

A Transport Accident Investigation Commission (TAIC) report found the rag was likely to have been left inside the aircraft in the Qantas Sydney maintenance hanger.

The Boeing 737-838, operated by Qantas subsidiary Jetconnect, was undergoing an overnight inspection in Auckland in June 2013 when an engineer inspecting the forward electronics and equipment compartment found metal filings.

The filings were near the cable drum of the stabiliser trim system, a flight control system that adjusts the amount of downwards or upwards aerodynamic force produced at the tail of an aircraft in flight.

The engineer found a rag had been caught under the cable wound around the drum, causing a bulge in the cable. This was wearing against aluminium spacers around the drum, damaging steel bolts holding them in place, and putting extra tension on the cables.

The trim cables, drum and pulleys were replaced before the aircraft was returned to service.

Testing of the rag showed it was the same type used in the Qantas maintenance facility in Sydney.

The TAIC report said in another incident in September 2013, a Jetconnect Boeing 737-838 flying from Melbourne to Wellington had trouble retracting its landing gear, and was found to have a rag wrapped around the landing gear assembly.

A Qantas investigation found the rag had been left behind after maintenance.

TAIC said the key lesson was that personnel should take care not to leave anything inside aircraft, particularly in areas or near systems critical to flight safety.

A Qantas spokesman said while the incident was a very rare occurrence, it had improved processes within the engineering department to ensure items were not left behind during maintenance checks.

"This particular aircraft is a next generation Boeing 737-800, which has some of the most modern and sophisticated systems in aviation, and at no time was the safety of the aircraft compromised."