LE BOURGET—Honeywell could offer a modified or an all-new power and thermal management unit (PTMU) to replace the company's Integrated Power Package (IPP) on the Lockheed Martin F-35, a company executive told Aviation Week here on June 17.
The incumbent supplier is working on both proposals as part of a two-year analysis of alternatives that Lockheed kicked off at the end of last year, said Lori Schneider, Honeywell's vice president of defense OEMs.
Both proposals would replace the 32-kW cooling and heat rejection capacity of the current IPP with a PTMU capable of 60-80 kW. Honeywell is competing for the potential upgrade program against the Collins Aerospace Enhanced Power and Cooling System (EPACS) and another supplier that has not been named.
Lockheed's two-year analysis will conclude with a recommendation, which will be submitted to the F-35 Joint Executive Steering Board to make a decision on which path to follow.
For Honeywell, a modification to the existing IPP would come in two parts. A software change could expand the capacity of the IPP to manage 25% more waste heat, with the limit rising to 40 kW, Schneider said. The second part would involve hardware changes, including new types of heat exchangers.
A decision to replace the IPP with a clean-sheet PTMU would be more complex, Schneider said. In addition to providing the engine start and back-up power generation capabilities of a traditional auxiliary power unit, the turbine-based system has 12 other functions, including pressurizing the cockpit.
“Every other aircraft has a more standalone [approach] with an environmental cooling system, thermal management, auxiliary power, emergency power as federated subsystems,” Schneider said. By contrast, the F-35's IPP combines “all of those core subsystems in one integrated system. So you're kind of trying to replace a one-of-a-kind circulatory system with something new.”