Preserving capacity, General Tom Lawson, Chief of the Defence Staff, Keys to Canadian SAR
Issue link: http://vanguardcanada.uberflip.com/i/139409
Next-Gen Fighter N n fuel transfer valve and other things, but they are also interfacing with the airplane," he says. "They are talking to the airplane all the time. About every 20-30 milliseconds, those computers sweep across [those] 400 sensors to determine the health and the performance of the engine. "This weapon system is more integrated than any other weapon system, particularly where the propulsion system is concerned. We are more integrated and interfaced with the aircraft systems than what you would see on any of the legacy jets." And that data can be downloaded by ground crews through a permanent memory device when the aircraft lands to assess all the performance parameters for that flight. At its core, the F-135 consists of two counter rotating spools that produce 40,000 pounds of thrust. The engine is designed in five basic modules that can be removed and replaced individually. The significance of the modular design is apparent as Stevens describes engine maintenance. Where legacy concepts typically have a three-stage process, starting at the flight line and moving back through a repair shop to a depot, the F-135 removes that intermediate layer. "If we introduced foreign material and damaged the fan," Stevens says by way of example, "we would remove the engine from aircraft, separate this fan, put it in a shipping container and send it to the depot; the depot would have sent us a fan (which had already been tested), we'd put it on the engine, roll the engine back into the aircraft, run the engine with some built in tests, and then determine if the airplane is serviceable. The same is true for all the rest of the modules. By eliminating that one level of maintenance we can help control sustainment costs for the future." Costs, of course, are a major consideration with the Joint Strike Fighter. The F135 engine, which is still in low rate production, is estimated at about $10 million dollars today, but Pratt & Whitney has implemented an aggressive cost reduction program, says Stevens, and is "meeting all the goals that have been established by the Joint Program Office. The cost continues to come down." Commonality across the three engine variants – conventional take off and landing, short take off and vertical landing (STOVL), and carrier variant – has also helped contain costs, O'Donnell said. So have changes to production processes as the engine transitions from development to full production. The company recently signed a low rate initial production (LRIP) 5 agreement that is six percent lower than its LRIP 4 contract, he added. "Last year we produced 48 engines and have produced 87 to date. [In 2013] we will produce more F135 engines than all of our other military engines combined. I think it is reflective of the success we have had on the program. Each year we've demonstrated the ability to double production on the production line," which is being matched by improvements to the supply chain. One of the companies in that chain is Ottawa-based GasTOPS, which designs and manufactures sensors that provide engine bearing and blade health data on all three variants to improve maintenance task management. The company is also developing a blade health sensor for the lift fan on the STOVL aircraft. In a questionnaire earlier this year to the companies contending for Canada's nextgeneration fighter program, the National Fighter Procurement Secretariat asked specially about engine performance under a variety of circumstances and mission configurations. During its briefing in Forth Worth, Lockheed Martin highlighted comparisons with its F-16 Fighting Falcon, including internal fuel carrying capacity (7000 lbs versus 18,000 lbs on the F-35) and engine thrust (29,000 lbs versus 40,000 lbs, though whether the F-35 burns fuel more rapidly to gain that thrust was unclear). Despite the temporary grounding in February, it's unlikely questions about the engine – from media and government – will fazed either Lockheed Martin or Pratt & Whitney. "This engine is probably more tested than any engine we've done before," Stevens says with some pride as the roar of a jet from overhead rumbles into the hanger. "We've got 25,000 engine operating hours just in the ground testing environment alone. We've done everything imaginable to this engine to get it to fail." Stan Stevens of Pratt & Whitney with the F-135 engine. www.vanguardcanada.com JUNE/JULY 2013 35