Qantas Airways will ground five aircraft and cancel around 100 domestic flights a week with union industrial action causing a shortfall in required maintenance services.

The Australian Licenced Aircraft Maintenance Engineers (ALAEA) has been taking industrial action for several months, including a ban on overtime work in place at maintenance facilities around the country and a 'go-slow' approach to work which has caused a backlog of maintenance.

The Oneworld carrier said it will ground four Boeing 737s and one Boeing 767 for at least a month.

"The industrial action from the licensed aircraft maintenance engineers' union is now making it difficult to clear maintenance tasks in a timely fashion," said Qantas CEO Alan Joyce.

"It takes about 15,000h per week to maintain the fleet. We are seeing a shortfall in maintenance capacity of over 1,200h per week or about 8%. This means a number of aircraft are not available each day which has caused a decline in schedule reliability. On-time performance has fallen from 87% four weeks ago to 77% today."

Australia's flag carrier said the flight cancellations will largely affect its services to and from Adelaide, Sydney, Brisbane and Melbourne.

It added that services by subsidiaries QantasLink, Jetconnect and Jetstar will not be affected.

Source: Air Transport Intelligence news