LONDON, JAN. 23 -- Pilots of British Tornado fighter-bombers are revising their tactics to decrease their losses, which are the heaviest among allied planes in the air attack on Iraq, defense officials said today.

The officials refused to specify what changes had been made, citing security considerations, but analysts said British pilots sent to bomb Iraq's air force runways and radar installations were almost certainly flying at higher levels than they had during the first days and may also be hitting different targets.

Five Tornados have been lost and eight British airmen are reported missing, including two put on Iraqi television as captured POWs. A missing airman was reported by Baghdad Radio to have been captured in southern Iraq today.

The British losses account for more than one-quarter of the total losses of 19 planes. The British are estimated to have about 50 Tornado or Jaguar planes in the region.

Senior military commanders contend the losses are due to the particularly dangerous missions the Tornados have been assigned. They have been using low-flying tactics to precision-bomb air fields with JP-233 runway cluster bombs and to hit radar installations with parachute bombs.

{A Pentagon official also noted that the British had munitions designed for low-altitude delivery. He said one plane had been lost due to a failure of its flight controls at takeoff, "but the Brits have been very good. Of all the guys over there, they have been leaning forward the most."}

Some Royal Air Force air crews reportedly have complained they have been given the most dangerous operations by American planners. But Air Vice Marshal William Wratten, Britain's air commander in the gulf, told reporters British losses remained "astonishingly low," given the fact they had flown over 400 sorties. "We have also had extremely bad luck and bad luck does not last forever," he said.

A senior British commander in London gave an upbeat description of the damage being done to Iraq's forces. Officials here acknowledged they were trying to alter the gloomy reaction to recent war news following the early euphoria.

Maj. Gen. Alex Harley, assistant chief of the defense staff, told reporters that the allied war effort was devastating Iraqi forces.