To the Air Force, it’s a “cover-center wall, troop compartment latrine ... required to protect the aircraft from ­corrosion damage in the latrine area.”

To the rest of us, it’s a toilet cover. And until recently, it had a price tag of $10,000.

Officials said last week that the U.S. Air Force paid about $10,000 each to replace toilet seat covers on the C-5 Galaxy, a Vietnam-era military cargo plane that is still in service, at least three times and as recently as last year.

The reason, they say, is that the plane’s manufacturer no longer produces the part, forcing the government to order a customized one when it needs to be replaced. More recently the service has been able to cut the average cost of the toilet cover to about $300 by using a 3-D printer, an approach that top officials want to replicate for other acquisitions.

The toilet part’s price was confirmed by Air Force media relations chief Ann Stefanek in a phone conversation and in a separate interview with Assistant Air Force Secretary Will Roper.

“We are not now, nor will we in the future, buy that aircraft part at that price, because we can now do so more cheaply using 3-D printing,” Stefanek said, referring to the toilet seat cover on the C-5. “Using this new process allows us to make parts that are no longer in production and is driving major cost savings.”

Their comments came after Sen. Charles E. Grassley, R-Iowa, raised the issue in a June 6 letter to Defense Department Inspector General Glenn Fine, who in turn cited a May 29 article in the trade publication Defense One. Grassley’s office released the letter publicly last week.

Air Force officials describe the $10,000 toilet cover as a case of supply-chain economics gone wrong.

The C-5 dates to the 1960s, when it was used to move troops and cargo during the Vietnam War. Lockheed Martin, the plane’s original manufacturer, shut down its C-5 production line in 2001 when the military stopped buying new models. But the Air Force still counts 52 in its fleet, and some of them have been put to use in Iraq and Afghanistan.

Keeping the old planes ready to fly means bits of hardware occasionally need to be replaced. Since the Air Force maintains painstakingly specific requirements for equipment components — even toilet parts — doing so is rarely as simple as a trip to Home Depot.

The Air Force says that with the Lockheed’s C-5 production line no longer active, there is no company with a fully staffed assembly line ready to produce exactly what it needs. That means the government has to hire a manufacturer to make a mold of the original toilet seat cover, redesign two-dimensional drawings to make sure the cover fits, manufacture a mold for the part, and then produce it — effectively reverse-engineering the toilet cover and building it from scratch.

A profit-minded government contractor might be persuaded to absorb those costs if it could spread them across hundreds or thousands of toilets. But when the payoff is just one sale, businesses demand a higher price.

Still, Air Force officials said such situations should be avoidable.

“If we can’t make [airplane parts] ourselves we have to live with what the market can produce at a profitable level,” Roper said. “But of course we should not be paying industry for something that we can make more cheaply ourselves.”

Lawmakers weighing whether to increase funding for the military do not appear to take that argument seriously. After all, it’s a toilet part.

In his letter, Grassley chided the Defense Department over what he called a “spare parts ripoff.” He drew parallels to a similar incident in the 1980s, also involving the C-5’s toilet, in which it was disclosed that the toilet seat itself cost $640. The toilet seat became a symbol of government waste in the Reagan era; longtime Washington Post editorial cartoonist Herblock would often depict Defense Secretary Caspar Weinberger with a toilet seat around his neck.