An air base’s penchant for pricey coffee cups has garnered the attention of a United States senator, who is demanding -- and receiving -- an explanation for the purchase of beverage tumblers that cost $1,280 each.

Sen. Chuck Grassley, R-Iowa, questioned the procurement in an Oct. 2 letter to Air Force Secretary Heather Wilson. Grassley's letter cited a September 26 Fox News article reporting that in the past three years the 60th Aerial Squadron at Travis Air Force base in California purchased dozens of cups for nearly $56,000. The cups can reheat liquids on board the Air Force's fleet of cargo aircraft.

The squadron reported that the cups have handles that break easily when dropped. Since replacement handles aren’t available, the whole cup has to be replaced. In 2016, the squadron said that it purchased 10 hot cups for $6,930 and that the price for each cup surged from $693 to $1,220 in 2018, resulting in a total expenditure of $32,000 for 25 cups. The math may have been off. That's actually a price of $1,280 for each of the 25 cups.

“You are right to be concerned about the high costs of spare parts, and I remain thankful to have your support in addressing this problem,” Wilson told the senator in a letter dated Oct. 17.

GRASSLEY WANTS AIR FORCE TO INVESTIGATE $1,280 HOT CUP

Wilson said the item in question is a specially manufactured electronic water heater that plugs into aircraft systems.

She told Grassley that the Air Force has purchased 391 of these items at a total cost of $326,785 since 2016 -- an average per-item cost of around $835.

“It is simply irresponsible to spend thousands of dollars on manufactured parts when we have the technology available to produce them ourselves,” Wilson said in her letter, which Grassley released Friday.

Wilson also said that the Air Force has recently created a 3D replacement handle fix “at a cost of about 50 cents each.”

Brig. Gen. Edward Thomas Jr., director of the Air Force Office of Public Affairs, told Fox News Monday that the Air Force's Air Mobility Command is no longer buying the electric heaters used in large transport aircraft as they work more cost-effective solutions.

"Our airmen reported prices doubled on this out-of-production part and found a solution using 3D printing," he said.

The Air Force lauded the innovative solutions of airmen at Travis AFB in June which was quickly followed by congressional inquiries into how the prices of the electric heaters, purchased through the Defense Logistics Agency, had dramatically climbed, according to Thomas.

The spokesman said the Air Force believes there is potential to save millions of taxpayer dollars through 3D printing of parts for older aircraft as they drive changes to prevent being held hostage by obsolete supply chain practices.

Grassley said Wilson’s letter leaves him with more questions.

AIR FORCE SQUADRON SPENDS $56,000 ON METAL COFFEE CUPS

“While I appreciate that the Air Force is working to find innovations that would help save taxpayer dollars, it remains unclear why it cannot find a cheaper alternative to a $1,280 cup,” he said. “Government officials have the responsibility to use taxpayer dollars efficiently. Too often, that’s not the case. I intend to pursue this issue further.”

A spokesman for the Travis squadron said the manufacturer of the hot cups is G&H Aerospace, a Arizona defense contractor. An email seeking comment from G&H executives was not immediately returned. A man who answered the phone at the firm's office Monday afternoon said "we have no comment" and hung up.

In July, Grassley demanded to know why the Air Force was buying toilet seat covers for $14,000 each.