Bell marks assembly and test milestones on first MV-75 Cheyenne II

Bell has finished assembling the first nacelle structures for the US Army's lead MV-75 Cheyenne II, according to the manufacturer. The components were joined to a wing at Bell's tiltrotor production centre in Amarillo, Texas, where the company has already built several wing sections for the type.

Testing has also begun on the first gearboxes for the initial MV-75 test aircraft. Bell says the gearboxes are at the heart of the tiltrotor's drive system and handle electrical power generation, hydraulic fluid pumping and cooling blowers for the engines and nacelles. They were designed and built at the company's Manufacturing Technology Center in Fort Worth, Texas, and the finished assembly is being evaluated at its drive system test lab in Grand Prairie, Texas.

At the Weapon System Integration Lab in Arlington, Texas, Bell is developing software for several MV-75 systems, including flight-control computers and large-area cockpit displays.

Bell said the nacelle completion, the start of gearbox testing and the software work amount to significant progress on the first test aircraft, bringing it and Team Cheyenne closer to finishing the build and beginning flight tests.

The MV-75 is in low-rate production, and Bell is working toward delivering the first example. The US Army says the troop-carrying tiltrotor will bring what it describes as transformational gains in speed and range to its rotary-wing fleet.

The nacelle design differs from that of the V-22 Osprey, Bell's in-service tiltrotor. On the V-22, the whole nacelle assembly, including the engine and proprotor, rotates during the transition between vertical and horizontal flight.