The EC-121K, the only American Airborne early warning and control radar surveillance aircraft that ever existed, crashed at Da Nang Airport, killing 23 of 28 on board on March 16, 1970.
The Lockheed EC-121 Warning Star was an American Airborne early warning and control radar surveillance aircraft operational in the 1950s in both the United States Navy (USN) and United States Air Force (USAF). After WWII, United Kingdom deployed a substantial AEW capability with American Douglas AD-4W Skyraiders, designated Skyraider AEW.1, which in turn were replaced by the Fairey Gannet AEW.3, using the same AN/APS-20 radar. 
