Davis-Monthan Inactivates Four A-10 Units, Ending the Base's Thunderbolt II Mission

The US Air Force inactivated four units at Davis-Monthan Air Force Base, Arizona, in a ceremony on September 18, 2026, a step the service said marks the end of the A-10 Thunderbolt II legacy at the base.

The units inactivated were:

• the 355th Operations Group
• the 357th Fighter Squadron
• the 357th Fighter Generation Squadron
• the 355th Training Squadron

According to the Air Force, the 355th Operations Group provided A-10 capability for close air support, forward air control and combat search and rescue from 1992 to 2026, and oversaw all formal A-10 pilot initial qualification and requalification training. The first A-10 arrived at Davis-Monthan in November 1975. Historical documents and memorabilia from the inactivated units are being transferred to the National Museum of the US Air Force at Wright-Patterson Air Force Base.

The Air Force release did not say where the A-10 mission or the aircraft go next, and named no replacement aircraft or unit for the base.

The inactivations are a base- and unit-level divestment, not the retirement of the type across the service. The Air Force has stated its intent to retire all 162 remaining A-10s in 2026, three years earlier than the 2029 date it had previously planned. Congress has not authorized that schedule: the FY2026 National Defense Authorization Act pared authorized retirements back to 51 aircraft and barred cuts in fiscal 2026. Under the Act, the Air Force may not reduce the total A-10 inventory below 103 aircraft during FY2026, and 93 aircraft must be designated primary mission aircraft until October 1, 2026.

GlobalMilitary.net's record of the US Air Force A-10C fleet shows how far the drawdown has already run. Active aircraft stood at 284 in 2022, 286 in 2023, 270 in 2024 and 234 in 2025, and stand at 162 in 2026. From the 2023 peak of 286, the fleet has fallen by 124 aircraft, or roughly 43 percent, in three years. The 2026 figure of 162 is also the number the Air Force said it wanted to retire that year: on the site's count, the service's stated intent covered the entire remaining fleet. The FY2026 Act cut that plan back to 51 aircraft.

Davis-Monthan has lost a second fleet in the same month. GlobalMilitary.net's air force event log records the retirement of the Air Force's EC-130H Compass Call electronic attack aircraft, whose last mission flew from the base on September 2, 2026. The same log records an A-10C left with a missing wing on September 9, 2026, damaged in an Iranian ballistic-missile barrage.

What follows the Davis-Monthan units is not yet public. The FY2026 National Defense Authorization Act required the Air Force to brief Congress by March 31, 2026 on the status of the fleet and on its divestment plan through FY2029, including how the service intends to replace the A-10. For now the United States holds a statutory floor of 103 A-10s for fiscal 2026, a service that has declared its intent to retire the type, and a base that has closed its A-10 units without a named successor.