GBU-43 Massive Ordnance Air Blast
The GBU-43/B Massive Ordnance Air Blast (MOAB) bomb, whose abbreviation is commonly considered a backronym pun meaning Mother of All Bombs,  is the highest-yielding non-nuclear guided bomb in the U.S. military inventory. With a high-explosive payload of 8480 kg (18700 lb), it is the successor to the 6800 kg (15000 lb) unguided BLU-82/B bomb, the heaviest that had been in the modern U.S. inventory.
It is slightly smaller than the GRAND SLAM bomb, designed by Barnes Wallis, used operationally in the Second World War by 617 Squadron, Royal Air Force. Even larger than the GRAND SLAM was the U.S. T-12 bomb, at 43,600 pounds. Both the GRAND SLAM and the T-12 were unguided hard target penetrator weapons with reinforced steel cases, as opposed to the GBU-43, which is optimized for surface blast. The availability of precision-guided munitions (PGM) has done away with the need for extremely large penetrators, since, if necessary, multiple PGMs can be delivered sequentially to the same crater.
Both bombs are delivered by MC-130 COMBAT TALON or equivalent aircraft. The unguided BLU-82, however, brought the vulnerable delivery aircraft too close to the target, and, at first, studies were directed at providing glide wings and guidance for it. Eventually, however, a more aerodynamic bomb casing was chosen, and the payload was increased.
It is not intended to attack deeply buried or reinforced targets, but to create a pressure wave over a large area. A typical application would be both detonating land mines in an area, and flattening obstacles to helicopter landing.
First tested in 2003, none have been used in combat, as opposed to the BLU-82.
- The "Mother of all Battles" was a favorite phrase of Saddam Hussein