Lawmakers in Washington have reached a year-end legislative agreement that will shape US defence spending in 2024 and sets up new reductions to the US Air Force’s (USAF’s) fleet of Fairchild Republic A-10 attack jets.

Both chambers of Congress passed the annual National Defense Authorization Act (NDAA), with the Senate approving the measure on 13 December and the House of Representatives giving its ascent on 14 December. The legislation must be signed by President Joe Biden before becoming law.

A-10 wyoming highway

Source: US Air Force

Air force leaders have sought for years to downsize the A-10 fleet, arguing that funds spent to keep the ageing craft airworthy would be better spent on acquiring more-capable multi-role fighters, particularly fifth-generation Lockheed Martin F-35s

Among provisions in the 2024 NDAA is one authorising the USAF to retire 18 of its A-10 Thunderbolt II attack jets – lowering the minimum required fleet size from 153 to 135. 

The new floor represents a 12% reduction to the service’s mandated fleet.

The move continues a trend begun almost exactly one year earlier, when Congress authorised the first A-10 retirements in the 2023 NDAA. That legislation lowered the minimum “Warthog” fleet to the current level of 153 aircraft.

Four months later, the USAF transitioned the first A-10C into long-term storage at Davis-Monthan AFB in Arizona, after the jet logged 43 years of operational service. When it touched down at the Davis-Monthan “Boneyard”, A-10 tail number 80-149 had recorded 14,125 flight hours over the course of its career.

At the time, Air Combat Command told FlightGlobal the USAF planned to retire 21 A-10s in 2023, prioritising the “least combat effective” airframes.

Senior USAF leaders have sought for years to downsize the A-10 fleet, arguing that funds spent to keep the ageing craft airworthy would be better spent on acquiring more-capable multi-role fighters, particularly fifth-generation Lockheed Martin F-35s.

The USAF has gone to considerable lengths to keep the Cold War-era A-10s flight-worthy. The service contracted with Boeing in 2011 and 2019 to produce all new wing sets for the fleet.

While new A-10 production ended in 1984, the wing sets from the Enhanced Wing Assembly replacement programme are meant to keep A-10s flying into the 2030s.

A-10GBU-39 test

Source: US Air Force

In April 2023, US Air Force test pilots successfully demonstrated that a single A-10 can carry and deploy 16 Small Diameter Bomb precision munitions, opening a new role for the ground-attack jet as a so-called “bomb truck”

The aircraft gained cult status among American ground combat troops for conducting low-level gun runs while providing close air support during the lengthy wars in Iraq and Afghanistan. That helped the famously rugged A-10 survive years of budget politics in Washington, where it was protected from retirement by members of Congress.

Designed to destroy tanks during close-air-support missions, the A-10 was built around a titanium bathtub cockpit to protect the pilot and a General Dynamics 30mm GAU-8A Avenger cannon. It has two GE Aviation TF34-100 engines mounted prominently above the tail section of the aircraft and can carry up to 7,200kg (16,000lb) of mixed ordnance, according to Boeing.

Tests performed by the USAF in 2022 determined that the A-10’s main cannon is still effective against the armour of modern main battle tanks, some 50 years after the aircraft was designed, although it remains vulnerable to modern air defences.

Despite limitations, the USAF continues finding ways for the slow, un-stealthy A-10 to stay relevant even without using its legendary canon.

Air force test pilots in April demonstrated that a single A-10 can carry and deploy up to 16 Boeing GBU-39 Small Diameter Bombs – a low-cost, precision-glide munition capable of striking targets from 40nm (74km) away.

When tensions in Europe and the Indo-Pacific region pulled the USAF’s most-capable fighters into active-deterrence missions against the modern air forces of Russia and China, A-10s were sent to patrol the Middle East.

The type was also included in the surge of US air power to that region in October, following the outbreak of war between Israel and Hamas in Gaza.