The latest critic of the U.S. Air Force’s ambitious — and pricey — plan for an all-stealth fighter fleet is one of the flying branch’s top stealth pilots.

Writing in the Air Force Research Institute’s Air & Space Power Journal, Lt. Col. Christopher Niemi, a former F-22 test pilot who later commanded a frontline squadron of the radar-evading jets, says the Air Force is making a big mistake by buying only the most expensive stealth fighters — namely, the F-22 and the newer F-35.

“An all-stealth Air Force fighter fleet deserves reconsideration,” Niemi asserts (.pdf). ”Stealth technology demands significant trade-offs in range, security, weapons carriage, sortie generation, and adaptability. Stealth provides no advantage in conflicts such as those in Afghanistan or Iraq (since 2003), and (despite its obvious utility) it cannot guarantee success in future struggles with a near-peer adversary.”

“Most importantly,” Niemi adds, “the cost of F-22s and F-35s threatens to reduce the size of the Air Force’s fielded fighter fleet to dangerously small numbers, particularly in the current fiscal environment.”

The test-pilot-turned-commander is in good company. Three years ago Gen. Harry Wyatt, head of the Air National Guard, said the Pentagon should consider acquiring cheap, upgraded versions of older warplanes to keep his squadrons at full strength.

More recently, the editors of the influential trade publication Aviation Week, a once-stalwart defender of the F-22 and F-35 programs, reversed its pro-stealth position and called on the Pentagon to consider new purchases of old-model planes. “There must be a hedge against further problems.”

But for a decade it’s been the Air Force’s policy not to purchase any non-stealth fighters. The flying branch has bought only so-called “fifth-generation” F-22s and F-35s from Lockheed Martin even as the cost of those fighters steadily increased.

The 187 F-22s cost $377 million a pop. The total bill to develop, buy and operate nearly 2,500 F-35s — 1,763 of them for the Air Force — tops $1 trillion. Rising costs have driven down the total number of jets the flying branch can afford.

The result: fewer than planned new planes to replace the fleet of nearly 2,000 fourth-generation F-15s, F-16s and A-10s acquired in the 1970s, ’80s and ’90s. As a consequence older planes have had to stay in service far longer than intended. “The Air Force’s fighter fleet is wearing out,” Niemi warns.

But even the inexorable aging of the current arsenal hasn’t swayed the Air Force brass from its all-stealth position, even though upgraded F-15s and F-16s are still available from Boeing and Lockheed, respectively. Senior officials have “viewed additional fourth-generation fighter acquisition as a direct threat to fifth-generation fighter programs,” Niemi explains.

Air Force leadership maintains the older designs simply won’t be effective much longer. “Sinking money into brand-new fourth generation [fighters] is just dumb,” said Gen. Mike Hostage, the head of Air Combat Command.

Niemi disagrees. He praises the F-22 for its high speed, altitude and stealth but points out its lack of range and ground-attack prowess compared to older jets. “The F-22 remains inferior to older fourth-generation fighters in some scenarios.”

The F-35 is a better bomber than the F-22 but is still too expensive to fully replace older planes, Niemi adds. The flying branch “could have acquired additional fourth-generation aircraft to mitigate developmental risk with the F-35.”

It’s not too late to reverse the policy, the former F-22 squadron command argues. “The Air Force should reconsider its long-standing position that fifth-generation fighters are the only option.”

When a man who spent his career flying stealth fighters begins lobbying against them, maybe it’s time the Air Force pays attention.