Small and simple are the virtues of the day for military engine makers, who are seeking to capitalise on growing demand for cheap, autonomous jets.
RTX subsidiary Pratt & Whitney (P&W) is joining the movement with a redesigned version of the company’s TJ150 one-stage turbojet, currently used to power missiles and decoy drones.
Speaking at the Farnborough air show on 22 July, P&W’s president of military engines Jill Albertelli, said the engine-maker is focusing on repurposing its existing line of commercial and military products, rather than developing an entirely new propulsion system.
“It means your supply base is already defined, it means that you might already be at a high volume of creating these engines,” Albertelli says.
Those economies of scale are a major asset in this case, with military operators like the US Air Force (USAF) seeking to rapidly field thousands of small, unmanned jets that can supplement conventional fighters. So-called collaborative combat aircraft (CCAs) are also meant to be substantially cheaper than conventional alternatives, putting pressure on manufacturers to deliver both cost savings and large numbers of jets.
P&W is focused on accomplishing that through design simplification. “What’s important for collaborative combat aircraft is being able to get that capability out in the field quickly,” Albertelli says, noting her twin goals for the TJ150 redesign are speed to market and simplicity.
The result has been a significant reduction in the number of components used to assemble the engine core, from roughly 50 in the original design to around five in new configuration. Those few parts can also now be produced with 3D printing – also known as additive manufacturing – for maximal efficiency.
“The team has basically redesigned such that you have just a handful of parts,” Albertelli says. “They all can be manufactured additively and provided to the customer much more quickly.”
Notably, key components can be produced on demand at the point of need, shortening logistics tails. P&W also hopes the new approach will reduce pressure on the aerospace supply chain, which Albertelli describes as already overburdened.
P&W plans to begin ground testing on the redesigned TJ150 engine in the coming months, with plans to launch flight testing in 2025. Albertelli reports “very high interest” from potential customers, with initial certification criteria focusing on missiles and decoy targets.
It represents an initial foray into a CCA market that could eventually represent thousands of new orders for both propulsion suppliers and aircraft manufacturers delivering the new class of vehicles.
Based on recent conversations at the Global Air Chiefs Conference in London earlier this month, Albertelli confirms there is robust interest on both sides of the Atlantic, with a potential market numbering in the thousands of orders.
“It’s not just the US talking about CCAs,” Albertelli says.
