Because of increased air operations against Islamic terrorists France has ordered more American BLU-117 bunker buster 909 kg (2,000 pound) bombs and BLU 126 LCDB (Low Collateral Damage Bomb) bombs. The bunker busters are well known, as they have a reinforced front end that enables it to penetrate many meters of earth or concrete before detonating (usually inside an underground facility).
The LCDB is quite different and less well known as it is a 227 kg ( 500 pound) JDAM (GPS guided smart bomb) with 89 percent of the explosives removed, and replaced with non-explosive material (so the bombs flight characteristics remain the same.) The remaining 14 kg (30 pounds) of explosives give the bomb a much smaller bang, and much less chance of nearby civilians getting hurt. Thus the LCDB has a bang that is closer to that of a 155mm artillery shell. The concept of the LCDB is not new. During the 1990s, the U.S. Air Force replaced all the 189 kg (416 pounds) of explosives with concrete in 909 kg laser guided bombs used against Iraqi anti-aircraft guns and missiles. This was because Saddam ordered his anti-aircraft weapons placed inside densely packed residential areas, in the hope that any American or British aircraft responding to fire from his anti-aircraft weapons would also kill lots of civilians. That would make for a great photo op, as Saddam was trying to turn himself into a victim of American and British aggression. Dead civilians helped a lot. Concrete smart bombs took out the anti-aircraft weapons, but rarely hurt any nearby civilians. The LCDB is used against targets in buildings, or out in the open, who need at least a little bang, and bomb fragments, to take out the bad guys.
Most of the additional bombs are being used by French warplanes stationed in Jordan to attack ISIL (Islamic State in Iraq and the Levant) targets in Syria. There ISIL is using a lot of underground facilities it captured from the Syrian military. A lot of these were built to obtain protection from Israeli air strikes. French pilots in Jordan are flying about 45 hours a month, which is three times what these pilots fly under peacetime conditions back in France. To keep the aircraft flying the French Air Force is also seeking to get 450 maintenance personnel back on active duty.