Bell‘s SPINE helicopter upgrade programme has moved into full fleet modification after the company was awarded an estimated $300 million US Navy contract to upgrade as many as 49 US Marine Corps rotorcraft.
The contract covers 28 AH-1Z Viper attack helicopters and 21 UH-1Y Venom utility helicopters under the Structural and Power Improvements for NextGen Effects programme, known as SPINE. Bell will begin modification work at its Amarillo Assembly Centre in Texas in mid-2027, with the first upgraded aircraft expected to be delivered in 2028.
What the Bell SPINE helicopter upgrade delivers
SPINE will give both variants greater electrical power and a new digital architecture designed to accommodate additional weapons, sensors and defensive equipment. The upgrade also provides support for Link 16, an advanced databus enabling long-range network-enabled weapons. Those capabilities are intended to allow H-1 crews to receive targeting information from other aircraft and operate as part of a broader network of US and allied forces.
The UH-1Y will additionally receive improvements to its fast-rope, hoist and litter equipment, supporting personnel recovery missions in remote or austere locations. The Marine Corps refers to the upgraded configuration as Series A, which includes improved defensive systems and enhanced digital connectivity alongside the increased electrical capacity.
‘SPINE will enable H-1 operators and maintainers to implement the equipment and technology needed to keep the aircraft as a fully interoperable member of the modern joint force throughout the lifetime of the H-1 fleet,’ said Danielle Markham, Bell Program Manager.
Col. Jason Duke, Program Manager for the US Navy‘s H-1 programme office, said the upgrades are designed to keep the fleet operationally relevant well into the next decade. ‘The SPINE program will provide a significant increase to overall H-1 electrical capability to optimize advanced battlefield technology and ensure the H-1 fleet will continue to be relevant into the 2040s,’ Duke said.
From prototype testing to Phase 3.0 fleet work
The new contract, designated Phase 3.0, moves SPINE from initial aircraft modification into full fleet delivery. Bell completed SPINE modifications on the first AH-1Z and the first UH-1Y in the autumn of 2025, sending both aircraft to Naval Air Station Patuxent River in Maryland for flight testing.
The contract covers an initial period and includes options that could extend the work for a further three years. It uses several payment structures depending on the type of work involved. Bell has described the total value as an estimate, meaning the US Navy has not necessarily committed the full $300 million.
The AH-1Z and UH-1Y share approximately 85% of their components, including engines, rotor systems, transmissions and avionics. That common design allows Marine Corps units to operate both the attack and utility variants together while reducing maintenance and logistics requirements, a practical benefit for expeditionary operations.
Bell completed deliveries on the Marine Corps’ 189-aircraft AH-1Z programme of record in 2022. The company delivered the last of 160 UH-1Ys included in the original programme in 2018. The combined Marine Corps fleet now stands at 349 Viper and Venom helicopters.
With SPINE Phase 3.0 now contracted and modification work scheduled to begin at Amarillo in mid-2027, the programme enters its most consequential stage: translating prototype results into fleet-wide capability across one of the Corps’ primary rotary-wing platforms.
