The UK Ministry of Defence is advancing its program to enhance the range and endurance of its Chinook heavy-lift helicopters. A modified airframe fitted with extended-range fuel tanks recently completed a key flight test milestone at RAF Odiham. Once certified, this upgrade will significantly expand operational reach for British Army and Joint Helicopter Command missions.
Extended Range Capability Targets Strategic Reach
The Chinook Extended Range (ER) modification centers on integrating auxiliary fuel tanks into the aircraft’s fuselage and sponsons. This configuration boosts internal fuel capacity by approximately 40%, allowing for significantly longer unrefueled flight durations. The goal is to support strategic lift operations over greater distances without relying on forward arming and refueling points (FARPs), which are vulnerable in contested environments.
According to Boeing and UK MOD sources, the ER configuration is based on lessons learned from U.S. Special Operations variants such as the MH-47G Block II and leverages similar tank integration techniques. The UK variant does not include aerial refueling capability at this stage but focuses on maximizing internal fuel volume while retaining full cargo capacity.
Flight Test Campaign Underway at RAF Odiham
The lead aircraft in the ER upgrade program—designated as a testbed platform—is undergoing a structured flight test campaign at RAF Odiham in Hampshire. Conducted by a joint team from Boeing UK, Defence Equipment & Support (DE&S), and No. 7 Squadron of the Royal Air Force (RAF), these trials are validating handling characteristics under varying weight distributions and mission profiles.
Initial tests have focused on verifying center-of-gravity shifts with full auxiliary tanks during hover transitions and low-level flight—critical for tactical insertions in austere terrain. Subsequent phases will assess endurance performance under different payload configurations and environmental conditions.
Operational Benefits for British Army Aviation
The extended range upgrade directly supports British Army expeditionary doctrine by enabling longer-duration air assault missions without intermediate stops. This is particularly relevant for deployments across Eastern Europe under NATO’s Enhanced Forward Presence (eFP) framework or rapid response scenarios in Africa or the Middle East.
- Increased loiter time: Enables sustained overwatch or casualty evacuation coverage during complex ground operations.
- Reduced logistical footprint: Minimizes need for forward refueling infrastructure in high-threat areas.
- Improved interoperability: Aligns UK capabilities more closely with U.S. Special Operations Forces using long-range rotary platforms.
This capability also enhances support to special forces elements such as the Special Air Service (SAS) or Special Boat Service (SBS), who often require deep insertion beyond conventional helicopter range envelopes.
Part of Broader CH-47 Modernization Strategy
The ER upgrade is one component of a broader modernization effort involving up to 14 new-build CH-47F Block II Chinooks ordered by the UK under a Foreign Military Sales (FMS) agreement signed in May 2021. These aircraft will feature advanced digital avionics suites (Common Avionics Architecture System – CAAS), improved drivetrain components including Advanced Rotor Blades (ARB), and structural enhancements to increase payload capacity and survivability.
The extended-range kit is being evaluated both as a retrofit option for existing HC6A/HC5 airframes and as an integrated feature on future deliveries of CH-47F Block II variants tailored to British requirements. However, cost constraints have led to some delays in finalizing full fleet conversion plans amid broader MOD budget pressures post-COVID.
Certification Timeline and Next Steps
If current testing remains on schedule, initial certification of the ER configuration could be achieved by mid-2025, allowing limited operational deployment within Joint Helicopter Command later that year. Full-rate integration across selected platforms would follow pending funding approval from MOD Main Gate decision-makers.
Boeing has indicated that lessons learned from this program could inform future export offerings of ER kits to other international Chinook operators seeking greater strategic mobility without aerial refueling infrastructure—particularly those operating in Indo-Pacific or African theaters where basing options are sparse.
