Boeing X-32 Stealth Fighter: Better Than the F-35?

Was the Boeing X-32 better than what would become the F-35 stealth fighter?

Opinions vary among experts. However, most say the Air Force made the right choice in the F-35.

Recent combat operations may prove that correct.

Boeing X-32 vs. F-35: The Debate Rages On…

However, we don’t think the debate is completely over just yet, as there is still much to discuss on this topic. National Security Journal recently published a multi-part series on the historic competition for the US military’s Joint Strike Fighter (JSF) 5th Generation stealth fighter program between Boeing’s X-32 and the Lockheed Martin F-35 Lightning II.

In the previous installments of this series, we discussed the X-32’s program origins and initial history, why it ultimately lost out to the F-35 (known at that time as the X-35) in the JSF competition, and whether it ever had a realistic chance of beating the Skunk Works jet.

Now that series has been expanded. In this next installment of the series, we shall examine a “what if” scenario: If the X-32 had actually won the bid, would it have had as many problems as the F-35?

Problem #1: STOVL Shortcoming

From reading an article by Charles Mitchell of Modern Engineering Marvels titled “Why Boeing’s X-32 Lost: The Untold Engineering Lessons Behind the F-35’s Triumph” (republished on MSN on or about 21 July 2025), quite possibly so, and maybe even worse.

In that piece, Mr. Mitchell describes the star-crossed, ill-fated X-32 within his opening paragraph as “a fighter aircraft whose technological hubris was undone by a combination of engineering compromises and the inexorable advance of stealth technology,” and in his closing paragraph deems it “a case study in the ruthless mathematics of contemporary fighter design, and a reminder that in aerospace engineering, brilliance and obsolescence can balance on the tip of a pin thermal loads, radar returns, or the power to hover without compromise.”

First and foremost was the core of the X-32 B variant’s short takeoff and vertical landing (STOVL) system.

In theory, it should’ve worked like a charm, as it was inspired by the STOVL system of a battle-proven and time-honored warbird, that being the Harrier jump jet. This was a direct-lift approach, which thrust from the cruise nozzle into lift nozzles through a single engine. This alternative, although mechanically straightforward, placed enormous thermal and mechanical stress on the engine and airframe, with hot exhaust being recirculated into the intake and restricting payload and range.

The range limitation factor makes the X-32’s loss to the X-35 a tad ironic, considering that the operational, production phase F-35 has ofttimes been criticized for its own range limitations, especially compared with China’s Chengdu J-20 Weilong (“Mighty Dragon;” NATO reporting name “Fagin”)!

The X-32’s range was 850 nautical miles (1,574 kilometers) on the US Air Force mission profile, 750 nautical miles (1,389 kilometers) on the US Navy mission profile, and 600 nautical miles on the US Marine Corps mission profile.

Problem #2: Stealth Shortcoming

Another shortcoming of the X-32 was its lack of stealth capabilities.

This was kind of a big deal, as stealth capability was part of the raison d’être of the JSF program in the first place.

The Boeing bird used a tailless delta wing, which was beneficial for structural efficiency.

The downside was that massive chin intake and overall geometry made radar signature management a somewhat dicey proposition, as direct visibility of the compressor blades enlarged the airplane’s radar cross-section, thereby creating a key vulnerability.

Problem #3: Aircraft Carrier Concerns

“Flexibility is the key to airpower,” quoth airpower theorist Gen. Giulio Douhet back in 1921, and operational flexibility was indeed a primary requirement of the JSF program, as it called for a shared airframe across USAF, USN, and USMC requirements (hence the “Joint” in “Joint Strike Fighter”).

The X-32’s ability to fulfill the naval variable of that equation was a significant question mark.

Mind you, modularity is usually considered a significant asset in military weapons systems, but ironically, in this instance, modularity was a liability.

To be more specific, Boeing’s employment of modularity mandated less-than-optimal compromises: its delta wing’s lack of horizontal tail surfaces restricted pitch authority, diminishing agility and complicating carrier approaches.

But not all agreed. X-32 test pilot Phillip “Rowdy”  Yates (CDR, USN, Ret.) was quite fond of the aircraft, declaring, “I would take that aircraft to the ship tomorrow. It was handling that smoothly and precisely.”

However, Navy test officials remained skeptical about the X-32’s ability to survive the harsh carrier environment.

By contrast, despite all the criticisms leveled at the Lightning II, its naval variant, the F-35C, appears to have no apparent problems landing on the flight decks of so-called “flattops.”

Problem #4: Inconsistency

To wit, there was an inconsistency between the two demonstrator airframes built for the JSF trials and what the X-32 would have looked like had it made it to the production phase.

Boeing intended to drop the variable intake, feature conventional tails, and rework the wing for production, a “change of horses mid-stream” that troubled the evaluators.

By contrast, Lockheed provided the evaluators with the benefit of “what you see is what you get (WYSIWYG),” as the X-35 took to the air in a form very close to its production offering, exhibiting an appearance of maturity and risk reduction that ultimately tipped the balance in Skunk Works’s favor.

Final Reckoning

All told, this quartet of quandaries doomed the X-32 and got it relegated to mere museum curio status. In fact, the video above is from our recent visit to the U.S. Air Force museum, allowing us to get within inches of the Boeing X-32.

But if it’s any consolation to Boeing, at least now they’re finally getting to one-up Lockheed Martin via the 6th Generation F-47 NGAD contract. Lessons learned, perhaps?

About the Author: Christian D. Orr, Defense Expert

Christian D. Orr is a Senior Defense Editor for National Security Journal. He is a former Air Force Security Forces officer, Federal law enforcement officer, and private military contractor (with assignments worked in Iraq, the United Arab Emirates, Kosovo, Japan, Germany, and the Pentagon). Chris holds a B.A. in International Relations from the University of Southern California (USC) and an M.A. in Intelligence Studies (concentration in Terrorism Studies) from American Military University (AMU).

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