MORE delay is dogging the eagerly awaited arrival of Apache helicopter gunships at Wattisham Airfield, near Stowmarket.Around half the Army's new £3 billion order of Apache attack helicopters will have to be mothballed for up to four years because pilots cannot be trained in time to fly them a Whitehall spending watchdog has warned.

MORE delay is dogging the eagerly awaited arrival of Apache helicopter gunships at Wattisham Airfield, near Stowmarket.

Around half the Army's new £3 billion order of Apache attack helicopters will have to be mothballed for up to four years because pilots cannot be trained in time to fly them a Whitehall spending watchdog has warned.

The National Audit Office said that although the aircraft were being delivered on time, a private finance initiative (PFI) deal to train the aircrew, struck by the MOD in a bid to save money, was three years behind schedule.

It has meant that dozens of aircraft will have to be stored away in hangars while the completion date for the initial training programme for 144 pilots is put back from April 2004 to February 2007.

However an MOD spokeswoman said that the NAO verdict was no surprise to MOD chiefs who had been working to have all Apache units operational by 2007 "for quite a while".

The set back is the latest in a string of problems in delivering to the front line the fearsome aircraft – said to be the most revolutionary development to warfare since the invention of the tank.

Problems with its radio system and debris from fired missiles interfering with the helicopter's rotorblades are also under investigation by the suppliers, Westland Helicopters.

Two army aviation regiments based at Wattisham, 3 Regiment and 4 Regiment, Army Air Corps, which are both part of the British Army's rapid deployment 16th Air Assault Brigade, will now have to wait even longer to get their hands on the £45m-a-piece tank-busting helicopters.

A third unit in the brigade, 9 Regt AAC, which is based in Yorkshire, will be first in line to trained and ready to operate the Apache, an American attack helicopter which has been modified for use in the British Army.

The delivery of the first fully equipped regiment of 16 Apache helicopters, scheduled for February 2005, is now in jeopardy, the NAO warned.

This will lead to a ``significant capability gap' in the Army's air-to-ground attack options as the life of the TOW wire-guided missiles on its ageing Lynx helicopters - which has already undergone one £14 million extension - could not be extended again beyond that date.

At the same time the duration of the training courses has had to be extended from 15 weeks to 26 - in part because the helicopter is now much more sophisticated than had been originally envisaged.

However the original programme was based on the experience of the US Army, which trains in Alabama, and had failed to take account of the fact that many more flying days are likely to be lost to poor weather in the UK.

As a result, the NAO said that between 2002 and 2006, a ``large number' of Apaches - some estimates say more than half - will have to be stored away in hangars at RAF Shawbury in Shropshire at a cost of £6 million. Already, 11 of the 25 helicopters so far delivered have been put into mothballs.