The Boeing YAL-1 Airborne Laser Testbed, (formerly Airborne Laser) weapons system is a megawatt-class chemical oxygen iodine laser (COIL) mounted inside a modified Boeing 747-400F. It is primarily designed as a missile defense system to destroy tactical ballistic missiles (TBMs), while in boost phase. The aircraft was designated YAL-1A in 2004 by the US Department