WASHINGTON, March 11: The US air force prepared to test its heaviest bomb, a 21,000-pound, satellite-guided conventional weapon, at a Florida range Tuesday as US troops ready for war against Iraq, officials said.

The Massive Ordnance Air Blast (MOAB) bomb is informally called the “mother of all bombs.” It would surpass the 15,000 pound “daisy cutter” as the largest conventional bomb in the US inventory.

When dropped, the massive explosion is expected to send up a mushroom cloud, similar to those caused by nuclear weapons, over a test range at Eglin Air Force Base in Florida.

“It could be used as a pretty devastating weapon against ground troops, a psychological weapon,” said Jake Swenson, an air force spokesman at the base.

“Any weapon of that magnitude will create a mushroom cloud, depending upon the debris on the surface,” he said.

The smaller “daisy cutter” was used in Vietnam to clear jungle for helicopter landing pads, in the 1991 war to clear minefields, and in Afghanistan to clear caves and strike fear in Al Qaeda and Taliban fighters.

Development of the bomb began last year at the Air Force Research Laboratory at Eglin last and was due to be completed late this year.

The MOAB has a satellite guidance system and a tail kit to steer it to within about 13 metres of its target.

It is so big it is pushed out of the back of a C-130 cargo plane rather than being dropped.

“It’s on a pallet. A parachute drags the pallet out, and the bomb swings off the pallet. The pallet continues on down on parachute. And the bomb goes along its merry way with GPS,” Swenson said.—AFP