WASHINGTON — Congressional appropriators have added $75 million to the UH-1N Huey helicopter replacement program for fiscal 2017 in order to expedite the program.

The president's budget request put forward last year asked for $18 million for the effort. The omnibus spending bill would bring that up to $93 million, budget documents show. That huge spending increase comes weeks after the U.S. Air Force issued a second draft request for proposals to industry.

The service's replacement efforts have drawn out longer than originally planned. The Air Force initially considered pursuing a sole-source contract for UH-60 Black Hawks to do the mission, but then reversed course after lawmakers pressed for an open competition. Then it hoped to select an off-the-shelf aircraft to fill the role, but none of the potential entrants met its requirements, so the service pushed its final RFP release out to the summer to allow competitors to figure out what non-developmental changes need to be made.

Now, it seems some in Congress are worried about the pace of the Huey replacement. Sen. Steve Daines, R-Mont., raised the subject of the $75 million increase in a Tuesday hearing of the Senate Appropriations Committee’s Defense Subcommittee.

"DoD has aircraft in the inventory that can fulfill this mission today," he told a panel of Pentagon officials, including acting Deputy Defense Secretary Robert Work. "Can you assure me that the Air Force will comply with congressional intent and that this opportunity will not be lost to a large bureaucracy, what we might call institutional inertia, or plain apathy in acquisition community?"

Work responded that Defense Secretary Jim Mattis has his eyes on the program and wants to see no further delays.

"When we briefed him on the way forward, he said: ‘Not good enough,' " Work said. "He said: ‘I want you to come back and ensure that we can meet the timelines.'

"He told us to make sure that we stay on track."

Two competitors have stepped forward with potential entrants. Sikorsky, which is now a Lockheed Martin subsidiary, will offer the HH-60U, a version of the UH-60 Black Hawk that incorporates modifications such as a rescue hoist and electro-optical sensor. Meanwhile, Boeing has partnered with Italian firm Leonardo to offer a militarized version of the AW139, which the companies have termed the MH-139.

The Air Force intends to buy 84 new armored helicopters capable of carrying nine fully loaded troops. Contenders should be able to maintain a 135-knot cruise speed and fly at least three hours, with an endurance of at least 225 nautical miles without needing to be refueled.

Under the current schedule, a contract award is slated for fiscal 2018, and the first delivery would occur in the 2020-2021 time frame. An industry day is planned May 8 and 9 at Wright-Patterson Air Force Base, Ohio, to answer questions about the second RFP.