Australian flag-carrier Qantas has grounded five Bombardier Q400 turboprops over concerns centred on the type's main landing-gear.

The aircraft are all operated by the airline's regional division, QantasLink, which has 21 of the type. It also ordered another seven last month.

Qantas says it has "temporarily removed" the five aircraft from service after inspecting specific undercarriage components. It has not detailed the nature of the problem.

The decision follows "incidents" experienced by an overseas operator of Q400 aircraft, says the airline, although it has not identified the carrier involved.

"Our approach to this issue, which requires the replacement of a main landing-gear fitting component, is consistent with Qantas' proactive, conservative and safety-first approach to every part of its operations," says chief executive Alan Joyce.

Qantas says it has also held discussions with Bombardier regarding the situation. It is unclear whether broader action, through an airworthiness directive, will be required.

"The issue is not an immediate flight-safety concern but does need to be rectified before each aircraft can return to service," says Joyce, adding that the work will take about a week for each airframe.

Sixteen other Q400 aircraft in the QantasLink fleet are unaffected. But the airline is nevertheless having to drop some of its services between Sydney and Canberra as a result of the withdrawal of regional capacity.

"Everything is being done to minimise any impact on [passengers]," says Joyce.

Bombardier has previously had to deal with concerns over the Q400's main landing-gear, notably following three separate landing accidents involving Scandinavian Airlines aircraft three years ago - a situation which prompted the carrier to axe its entire Q400 fleet.

Source: Air Transport Intelligence news