WASHINGTON - The US Air Force is grappling with how to manage a potential glut of drones and may eventually scale back the number of combat missions flown with unmanned aircraft by more than 25 per cent, the service’s top commander said on Wednesday.

Gen. Mark A. Welsh III, the Air Force Chief of Staff, said that the Predator and Reaper drones that have been a mainstay of the wars in Afghanistan and Iraq are not well suited to many other regions where the US military is looking to bolster its presence, such as the Pacific. “I am a big fan of UAVs where they make sense,” he said, referring to Unmanned Aerial Vehicles. “We shouldn’t rush into buying a whole bunch of remotely piloted aircraft just because we can.”

Welsh’s comments at a breakfast sponsored by the Defence Writers Group are the latest sign that the Air Force may have overfed its once-insatiable appetite for drones.

Under plans pushed by then-Defence Secretary Robert M. Gates at the height of the Iraq and Afghanistan wars, the Air Force was supposed to buy enough drones and train enough crews so that it could fly 65 combat air patrols round-the-clock by 2013.

The Air Force never quite reached that high, having maxed out at 62 combat air patrols today. Welsh said that the service would probably reduce that number substantially. Although officials haven’t finalised a figure, he said “in the vicinity of 45 would be a good start.”

It takes upto four drones to provide 24-hour coverage for a single combat air patrol.

Although the aircraft are unmanned, they require lots of personnel to fly them by remote control and provide support on the ground - about 400 to 500 people for each combat air patrol.

“I don’t know where we’re going to go, but building bigger, more expensive, more cosmic drones probably isn’t the answer,” Welsh said. “There’s nothing cheap about them.”

The armed Predators and Reapers are tailor-made for counter-terrorism operations and war zones such as Afghanistan, where the US military controls the skies and the enemy lacks sufficient firepower to shoot down the drones. But the slow-moving planes aren’t designed to withstand anti-aircraft defences or air-to-air combat.

Welsh told reporters that the Air Force needs to spend more on other methods to conduct reconnaissance and gather intelligence from the air.  He declined to be specific, but other Air Force officials have advocated more money for satellites, manned spy planes and advanced stealth drones, as well as more-powerful electronic sensors for surveillance.

In Asia, the Air Force is still planning to expand its use of another kind of surveillance drone - the Global Hawk - which can stay aloft much longer and fly far greater distances than the Reaper or the Predator. Unlike those drones, the Global Hawk is unarmed.