The United States Air Force is planning a raid on your pocketbook. Officials aren’t being subtle about it, but they are being secretive.

The secrecy involves the development of the Air Force’s next long-ranger bomber, dubbed the B-21 Raider. Air Force officials released an artist’s rendition of the plane last month and a few more details, most notably: The winning contractor is Northrop Grumman, and the current plan is to buy around 100 of them at an estimated cost of $556 million for each plane. But Air Force officials aren’t disclosing to taxpayers the full value of the contract they signed with Northrop Grumman.

Secrecy in government procurement can be appropriate. Indeed, there’s an entire system in place to develop and buy so-called “black” weapon systems. These are programs so secretive that they’re kept hidden from the public and revealed only to a handful of congressional oversight officials. The Air Force, for instance, developed the F-117 stealth fighter as a black program but didn’t acknowledge its existence until several years after the aircraft became operational in the 1980s.

The B-21 is now an acknowledged program, designed as the follow-on to current Air Force bombers. Withholding the total costs of such a program sets a dangerous precedent for transparency in government procurement. Indeed, hiding the cost from the public is about burying embarrassing cost overruns and dodging oversight, not protecting secrets.

Senator John McCain (R-AZ) is the chairman of a key Senate committee responsible for oversight of the Pentagon. He believes taxpayers deserve more details about the cost of this program. As the chairman, he would seemingly have the power to force the Pentagon to release the full cost data. His draft of the Fiscal Year 2017 Pentagon policy bill required the Air Force to release more cost information. Unfortunately, Senator Bill Nelson (D-FL) decided that cost details should be kept buried in Air Force files. In a committee vote, Senator Nelson’s nonsensical view prevailed. And so, for the time being, the Air Force can keep the public in the dark on the real cost of the B-21 program.

None of the military services are very good at predicting what they will pay for a weapon system, but the Air Force holds the dubious distinction of being particularly bad at cost estimates. The services all overinflate the number of aircraft/vehicles/missiles they say they’re going to buy. They then add up some development and all procurement costs, divide that dollar figure by the number of items they say they’re going to buy, and arrive at a supposed “unit cost.” Inevitably, either the Office of the Secretary of Defense or Congress breaks the news to the military service that they won’t be buying “X” number of planes or tanks. This change raises the per-unit cost because sunk costs, or those already incurred, are spread over fewer items that are being purchased. The services then cry foul, stating the ever-rising unit cost is actually the product of the decision to buy fewer items. But that argument bears little resemblance to reality because the original overall cost estimate is almost always just a wild guess.

Against this background, the nominee to be the new top general in the Air Force was recently questioned by Senator McCain about the decision to keep the total contract value secret. General David L. Goldfein had this to say: “And, Chairman, I agree with you, and I believe that if we are not transparent with the American people on the cost of this weapon system, through its elected leadership, then we have a good chance of losing this program.”

We agree with Senator McCain and General Goldfein. That’s why, earlier this week, we awarded the United States Air Force our “Golden Fleece” award for failing to fully disclose all the costs of the new B-21 Bomber.