Dust Devils, created as a Pursuit Squadron (Interceptor) in 1939 which served until 1946. Redesignated 21st Special Operations Squadron saw combat in Southeast Asia from November 1967 to August 1973.
Joined the 20th Helicopter Squadron in South Vietnam in Sep 1967. In summer 1968, the unit took on the CH-3C of 20th SOS.
In 1975 was again in front line during the April evacuation of Saigon and the rescue of the SS Mayaguez in May before inactivating on September 22, 1975 at U-Tapao, Thailand.
The squadron reactivated in May 1988 at RAF Woodbridge, UK when was splitted from 67 ARRS 21st SOS was deactivated in 2007 with the retirement of the MH-53M Pave Low IV. The replacement aircraft, the CV-22B Osprey tilt-rotor, was assigned to 7th SOS.
In July 2019 was reactivated with CV-22 Ospreys based Kadena, Japan.
Joined the 20th Helicopter Squadron in South Vietnam in Sep 1967. In summer 1968, the unit took on the CH-3C of 20th SOS.
In 1975 was again in front line during the April evacuation of Saigon and the rescue of the SS Mayaguez in May before inactivating on September 22, 1975 at U-Tapao, Thailand.
The squadron reactivated in May 1988 at RAF Woodbridge, UK when was splitted from 67 ARRS 21st SOS was deactivated in 2007 with the retirement of the MH-53M Pave Low IV. The replacement aircraft, the CV-22B Osprey tilt-rotor, was assigned to 7th SOS.
In July 2019 was reactivated with CV-22 Ospreys based Kadena, Japan.
The 21st SOS also flew Operation Eagle Pull, the evacuation of Vientiane, in 1975 while stationed in NKP Thailand
The 21st was also tasked Eagle Pull for the evacuation of Pnom Penh, Cambodia
The 21st SOS was never stationed at U-Tapao. It was stationed at NKP during the period that it was in Thailand. I know because I was there
Locations
| 1967-1975 | VTUW KOP |  Nakhon Phanom West |
| 1975 | VTBU UTP | U-Taphao International Airport |
| 1988-1992 | EGVG |  RAF Woodbridge |
| 1992-1995 | EGWZ AYH | Alconbury Weald |
| 1995-2007 | EGUN MHZ | RAF Mildenhall |
| 2019- | RODN DNA |  Kadena AB |
Models
| 1968-1975 | CH/HH-3 |
| 1968-1975 | CH/HH-53 |
| 1988-1998 | CH/HH-53 |
| 1998-2007 | MH-53M Pave Low IV |
| 2019- | CV-22 Osprey |