AMARILLO, Texas—Bell Helicopter Textron [TXT] has cut nearly 40 percent of production build time for its very first V-280 from what it initially predicted by focusing on reducing flight hour cost while increasing reliability and maintainability, according to V-280 Program Manager Chris Gehler.
Bell Executive Vice President for Strategic Communications and Chief of Staff Robert Hastings told Defense Daily March 1 during a tour of the company’s massive production facilities here that the company is infusing new materials, new design and simplification throughout the development process for its new tiltrotor aircraft. Bell improved the production and design of the nacelles, blades and wing skin for the V-280.
Bell, Hastings said, went with a fixed wing on the V-280 as opposed to the swept wing on the V-22, which reduced the parts involved with the wing. Gehler told Defense Daily in a March 3 phone interview that going with the fixed wing cut over 50 percent of the cost of that wing because it didn’t have a forward sweep nor a dihedral like on the V-22. The V-280’s wing is about the same size as the V-22, Gehler said, but costs less than half as much.
Hastings said the straight wing also eliminates the mid-wing gear box, which reduces both weight and cost. Bell Production Manager Shannon Massey said March 1 the fixed wing keeps the interconnect drive shaft, which maintains capability in case the aircraft was to lose an engine during flight.
The V-280’s simplified nacelles improve maintenance and the ability to transfer in flight from vertical lift to horizontal flight, according to John Bowman, Bell’s V-22 assembly manager. Bowman said the V-22 has to lift the nacelles to go from airplane mode to helicopter mode. Bowman said the V-280 doesn’t do this; it only rotates the tilt access gear box while the nacelles stay stationary. Bowman said Bell builds all its gear boxes in-house: prop rotor gear box, tilt access gear box and mid-wing gear box.
Gehler said Bell simplified the nacelle by keeping the engine on the outer most part of the wing tip and separating it out of the pylon nacelle that rotates. He said in a V-22, all of that rotates with the prop rotor in the cell, making the engine inherent and integral to the system. Gehler said that creates maintenance challenges as the engine has to be specifically designed to be able to operate in a 90 degree rotation.
Gehler said instead of having to remove parts to get at other parts, the V-280 nacelle was designed so that the entire nacelle doesn’t have to be pulled to get to screws at the bottom that need to be replaced. Bowman said simplifying the nacelle will make it much easier for maintainers to maintain the part. He said the V-22’s nacelle was much more compact and populated and that the company tapped its best V-22 maintainers for ideas on how to improve the nacelle for the V-280.
Bell, Bowman said, also simplified not only the design of the V-280’s wing skin but also the amount of work and labor required for production. Gehler said that V-280 wing skin construction is made out of a broad goods material in an 80 square foot sheet, as opposed to the V-22’s wing skin, which was laid out in one inch strips with a robotic tool that laid the strips in various angles. Gehler said using the large broad goods material sheet cuts man hour time by about half.
Gehler also said the robotic machine that laid out the V-22’s wing skin in one inch strips took days, weeks and months to build out the thickness and material length. He said that not only does using the 80 square foot sheet save time and money, but it also provides better durability as it is newer, stronger and stiffer than the wing skin material found on the V-22. The V-280, Gehler said, has fewer machining requirements as the V-22 does.
Bell, Gehler said, slashed the cost of producing the V-280 blades in half compared to the V-22, though the blades are very similar. He said the yoke, to which the blades attach, are all composite with similar materials, but utilize different tooling techniques and a different build methodology. Gehler said this allows Bell to focus on producing blades more easily with higher yield rates.
Bell believes its Digital Tread concept is also helping drive down V-280 costs. Hastings said Friday that Digital Thread is an idea that the entire aircraft, every single part and all the characteristics of the part, is designed in 3D. This, he said, ensures the parts fit together perfectly the first time, allowing suppliers to manufacture perfect parts.
Hastings also said that digital signature feeds into the development of simulation and into development of the maintenance procedures. Hence, he said, the idea of a thread throughout the lifecycle of the aircraft.
Bell was performing vibration testing on the V-280 on March 1. Hastings said Friday vibration testing was still being performed the week of March 6. He said ground testing will continue through the V-280’s first flight in September.
At its peak, Bell was producing 40 V-22s per year. Now it is producing 20. It is currently in negotiations with the Marine Corps for another batch of aircraft known as “multiyear 3.”
Bell is participating in the Army’s Future Vertical Lift Joint Multirole and Tech Demonstrator phase with V-280. Lockheed Martin’s [LMT] Sikorsky is also participating by teaming with Boeing [BA] to offer the SB>1 Defiant aircraft.