THE US Army hopes to refurbish at least 300 ageing Boeing Chinook heavy-lift helicopters to an improved-cargo- helicopter (ICH) configuration, but the $3.3 billion rotorcraft modernisation effort is competing for limited funding against other weapons programmes.

The critical Operational Requirements Document (ORD) is now being drafted. It advocates seeking $70-$80 million in research and development (R&D) funding, between fiscal years 1998 and 2003 to initiate the ICH project.

The funding issue will not be resolved until later this year as the US Army finalises its FY98 budget request.

Four pre-production ICH Chinooks would be built with the R&D money. Twelve CH-47D ICHs would follow, and 24 Chinooks would be modified each year until 2015, when all 300 are expected to have been modernised.

More of the twin-rotor CH-47Ds could be upgraded if the planned Joint Transport Rotorcraft (JTR) - the CH-47D and Sikorsky CH-53E replacement -is delayed. The US Army's fleet includes 431 CH-476Ds, 11 MH-47Ds and 25 MH-47Es.

One-third of the $3.3 billion would be used to install the AlliedSignal Engines T55-GA-714A power plant, which offers 22% more power than the T55-L-712, which is now installed. The new engine would allow the Chinook to meet its extra lift requirement.

About $2 billion would be spent on airframe and avionics improvements and vibration reduction efforts. The ICH aircraft remanufacture project would give the CH-47D a 20-year life extension. If funding is found, Boeing would like to add an elastomeric rotor hub, an air-transportability kit and an improved internal cargo-handling system.

Source: Flight International