EIGHT chinook helicopters that have been grounded at RAF Odiham for the past five years are to be made operational.

The chinook mark 3 helicopters were originally supposed to be in service in 1998, but were part of a massive commissioning bungle.

Software developed under a separate contract and designed for special operations failed to work.

The problems restricted the helicopters to flying above 500ft in clear skies with pilots navigating using landmarks, meaning the chinooks have only been used on limited trial flights.

In May, plans were put forward to bring the white-elephant helicopters into service and, last week, the Ministry of Defence (MoD) finally agreed the project to convert the eight chinooks.

Once operational, they will join the existing fleet of 40 and will be based at RAF Odiham. The first helicopters are expected to be operational by 2009.

Defence Secretary Des Browne made the announcement earlier this month.

He said: "Helicopters play a vital role in supporting our operations in Iraq and Afghanistan. That is why we are taking measures to make more helicopters available to operations as fast as possible."

The overall cost to the defence budget to modify the helicopters is expected to be £90.1million, of which £62million is the contract with Boeing.

Chinook helicopters can carry up to 55 troops or 10 tonnes of freight and can be used for search and rescue or casualty evacuation.

The aircraft can safely land and lift off again from water and can carry up to five Land Rovers and, with a twin rotor design, the Chinook is one of the few helicopters that can carry a payload equivalent to its own weight.