The B-2 is the oldest stealth aircraft in the current US inventory. It's been operational since the 1990s and has seen combat over Kosovo, Afghanistan, Iraq and Libya.

A crew chief performs a pre-flight check on a B-2 at Whiteman AFB, Missouri home of the 509th Bomb Wing.

Crew chiefs discuss pre-flight checks on a B-2 Spirit before take-off at Whiteman AFB, Missouri.

A B-2 Spirit takes on fuel from a KC-135 Stratotanker over the Indian Ocean.

French Air Force C-135FR tankers and a single An-124 transport on hire from Antonov Airlines at BA172 Kossei-N'Djamena in Chad on January 25, 2013 during the second week of Operation Serval.

A weapons specialist guides a GBU-39 into the main weapons bay of an F-22.

In August 2012 the Alaska-based 477th Fighter Group and 525th Fighter Squadron became the first operational F-22 units to drop GBU-39s. Flying from Hill AFB, the F-22s dropped the GBU-39s on the Utah Test and Training Range as part of the USAF's Weapons System Evaluation Programme.

The F-22-equipped 199th Fighter Squadron, Hawaii Air National Guard based at Joint Base Pearl Harbor-Hickam is a joint air national guard-active duty squadron assigned to the Pacific Air Forces.

F-22 04-4078/'HO' is one of 21 Raptors assigned to the 7th Fighter Squadron at Holloman AFB, New Mexico. Transfer of the 21 aircraft to Tyndall AFB, Florida was 'frozen' by the delay in passing the National Defense Authorization Act and is now due to take place in 2014.

F-35A AF-04 with an emergency spin chute installed during a high angle of attack test flight from Edwards AFB, California on November 3, 2012.

F-35B BuNo 168313/'VM12' is currently assigned to VX-23 'Salty Dogs' at NAS Patuxent River, Maryland to augment the ongoing JSF flight-test programme. The aircraft will eventually be re-assigned to VMFAT-501 'Warlords' based at Eglin AFB, Florida.

F-35B BF-03 completed the first weapons release of an inert 500lb GBU-12 laser-guided bomb over the Atlantic Test Range on December 3, 2012.