Sustaining What Issues: An Engine Match for the F-35 

The looming determination on the way forward for the F-35’s engine—Pratt & Whitney’s F135—has fostered loads of debate, with some suggesting the F135 must be utterly changed with a brand new engine via the Adaptive Engine Transition Program (AETP), whereas others say integrating a brand new adaptive engine into the F-35 could be wasteful and pointless.

Even Pratt & Whitney—which is creating its personal adaptive engine, the XA101, via AETP—insists that the F-35’s continued aerial dominance as a joint strike fighter relies on incremental upgrades to the present expertise powering it.

“Adaptive engines are sixth-gen expertise,” stated Jen Latka, Vice President of Pratt & Whitney’s F135 program. “That expertise is what retains us on the forefront when it comes to the U.S.’s nationwide benefit, so we’re very grateful for the adaptive engine program—however whereas it’s important to develop sixth-generation propulsion applied sciences, the AETP engines aren’t optimized for the F-35 program.”

The answer proposed by Pratt & Whitney, a Raytheon Applied sciences firm, is an engine core improve (ECU) that may meet DOD imperatives for the F-35 that adaptive engines can’t, notably sustaining tri-variant commonality (as a result of adaptive engines received’t match within the F-35B and sure received’t be retrofitted into already fielded F-35s), and won’t ship a significant amount of Block 4-enabled F-35s by 2028, when the warfighter wants them.

The ECU is a restricted scope improve—the product appears similar to the present motor within the F-35 however incorporates the most recent design instruments into the identical provide base. The improve wouldn’t require any of the F-35’s interfaces to vary and is restricted to what Latka calls “the facility module,” which is simply the core of the engine.

“What meaning is you possibly can come into depot in your regularly-scheduled overhaul with the present configuration after which depart depot with the upgraded core,” Latka stated. As a result of the upgraded engine is retrofittable, the improve could possibly be dropped in F-35s within the depot along with on the meeting line—significantly accelerating the tempo at which Block 4-enabled F-35s will attain the operational fleet.

Pratt & Whitney estimates that the ECU can save the DOD a complete of $40 billion over the lifetime of this system, however in near-term financial savings alone it has a transparent benefit over a brand new engine. Latka reviews that growth will value round $2.4 billion for your complete Engineering and Manufacturing Improvement part over the five-year Future Years Protection Program (FYDP). That’s only a fraction of the value tag on absolutely creating an AETP various, which Secretary Frank Kendall has stated will value practically $7 billion and end in lowered procurement volumes.

“Within the subsequent 5 years, there’s billions of {dollars} that could possibly be saved,” Latka stated. “And it’s not solely the price of a brand new engine—it will be that plus the core improve, as a result of the core improve will have to be finished regardless, to assist the worldwide clients and the STOVL variant.”

And in evaluating manufacturing prices, the core improve stays the financially prudent choice. On a per-engine foundation, an upgraded F135 could be manufacturing value impartial, whereas the preliminary value of a brand-new adaptive engine would initially be about thrice that of ECU, she stated.

“We’ve already come down the training curve and brought out 50 % of the price of the engine,” Latka stated. Even accounting for an AETP studying curve, Latka says AETP “would nonetheless be dearer than the present motor as a result of it’s considerably heavier.”

Whereas the financial savings provided by Pratt & Whitney’s single growth program are spectacular, they’re marginal in comparison with lifecycle financial savings. Sustainment is a vital piece of the controversy over F-35 engines, however its implications lengthen past simply the fee. Pratt & Whitney’s answer can doubtlessly save the Pentagon tens of billions of {dollars} over the F135’s (and the F-35’s) lifecycle as a result of it retains an infrastructure that has already been constructed and invested in—and when sustainment efforts are disrupted, disruption quickly follows.

“With a brand new adaptive engine, you’re going on the market and having to create a second infrastructure,” Latka stated. “So, you would wish all new tooling, all new assist tools, and all new depots. You must fund two sustaining engineering groups, two configuration administration groups … you have got two of every part since you’re sustaining two completely completely different merchandise.”

Bifurcation threatens the interoperability of the Joint Strike Fighter (JSF) program, which relies on a typical engine and international spares pool amongst American and worldwide F-35 operators. The upkeep, restore, and overhaul (MRO) community dedicated to the F135, as an illustration, already has a number of places across the globe that may be capable to assist ECU sustainment as nicely—with extra deliberate sooner or later. However F-35As powered by AETP engines wouldn’t be capable to make the most of that intensive sustainment community and would wish to face up a parallel AETP sustainment community at a big value.

“The drive proper now has received to be round maximizing interoperability among the many companions,” Latka stated. “One other difficulty is whether or not the adaptive engine is exportable; it’s sixth-gen expertise. Maybe it could possibly be exportable in the future, nevertheless it doesn’t look like proper now.”

And with international tensions on the rise, Latka stated, there’s a strict timeline on not solely enhancing the F-35’s working capabilities but additionally rising the fleet earlier than a possible battle occurs. That’s more durable to do whereas making an attempt to suit model new, unproven engine expertise into an present jet.

“Once we take into consideration the timeline and the pacing threats, slicing tails hurts that struggle,” Latka stated. “However secondly, we have to discipline an engine improve as quick as we will.”

Whereas adaptive engine expertise boasts improved vary over the present F135, Latka stated that these enhancements might distract from what actually issues to the combatant commanders: getting as many Block 4-enabled jets fielded as rapidly as doable. Block 4 amount and readiness equals related functionality.

Pratt & Whitney has stated its upgraded engine will likely be able to enter service by 2028, facilitating SECAF’s readiness crucial whereas providing efficiency enhancements and important value avoidance that permits elevated funding within the Secretary’s different operational imperatives. However Latka reiterated that these enhancements are ancillary to making sure operational readiness—it’s amount and Block 4 capabilities that really matter, and Pratt & Whitney’s Engine Core Improve would ship each whereas saving billions of {dollars} and guaranteeing commonality throughout the fleet of F-35s operated by the DOD and allied companions across the globe.