Airlift begins for Operation Just Cause, in which USAF plays a major role, including air strikes, airlift, airdrops, and aerial refueling. The F-117A stealth fighter is used operationally for the first time. In the largest night-combat airdrop since World War II, USAF aircraft transport 9,500 airborne troops from various locations to Panama in fewer than 36 hours. An AC-130H crew (mission #1J1600GA354) of the 16th Special Operations Squadron receives the 1990 Mackay Trophy. Active, Air National Guard, and Air Force Reserve Command special operations crews participate in Just Cause.
The Air Force Research Laboratory has signaled to industry it wants to develop a low-cost hypersonic cruise missile to deliver a wide range of payloads at a range up to 500 nautical miles.