House lawmakers who craft the defense budget are voicing concerns about the Pentagon’s proposal to cancel a variant of the Global Hawk unmanned aerial vehicle.

Defense Secretary Leon Panetta and Chairman of the Joint Chiefs of Staff Army Gen. Martin Dempsey appeared before the powerful House Appropriations Defense subcommittee (HAC-D) yesterday for the third day of hearings on the $525.4 billion defense budget the White House proposed on Monday.

HAC-D Chairman C.W. “Bill” Young (R-Fla.) expressed concerns about the $487 billion in cuts to the Pentagon’s 10-year spending plans imposed by the deficit-cutting Budget Control Act of 2011.

He argued the “magnitude of these reductions presents a danger the (Defense) Department has not seen since the peace dividends of the 1990s.” He noted, in written comments, that the majority of the reductions have come from investment accounts.

He lamented, in the prepared remarks, that “programs that were argued as strategically important–if not imperative–as recently as a few months ago” have “been abandoned in the name of budget savings.”

He highlighted the Pentagon’s move to terminate Global Hawk Block 30 unmanned reconnaissance aircraft program. The Pentagon maintains the variants of the drones will rise in the coming years and it can save money by using extending its use of the comparable manned U-2 spy plane.

“For years this subcommittee has been told the U-2 is too costly to operate and would be replaced by a less expensive platform in the Global Hawk,” Young said, adding this position was “verified as recently as seven months ago” when the Pentagon had to recertify the need for the Global Hawk to Congress, something it had to do under the Nunn-McCurdy law because the cost of the drone rose.

“Now, after sinking billions of dollars into the development of the Global Hawk Block 30, the decision is made to not only terminate production, but abruptly retire all the aircraft we have recently fielded,” he said.

Panetta told the HAC-D he also questioned the Air Force’s move to cancel the drone variant, “because I’m big on unmanned systems, both from my prior role (directing the CIA) and this role, and I think that’s something you have to invest in.”

“They said, look, if you look at the cost-effectiveness here, actually you can provide even an better picture at a lesser cost and it does the job,” Panetta maintained.

Rep. Peter Visclosky (D-Ind.) voiced concerns during the hearing about the Global Hawk Block 30, noting the Nunn-McCurdy certification said the U-2 would cost $220 million per year more than the Global Hawk.

Global Hawk contractor Northrop Grumman [NOC] has pledged to fight the Block 30 termination. It has support in Congress from lawmakers including House Armed Services Committee Chairman Howard “Buck” McKeon (R-Calif.) and Senate Armed Services Committee member Sen. Scott Brown (R-Mass.).

The HAC-D’s Young, meanwhile, also lamented the Pentagon’s proposal to delay by two years the nascent effort to develop a SSBN(X) ballistic-missile submarine to replace the current Ohio-class boomers.

“This comes after many years of the (Defense) Department warning this subcommittee that this portion of the strategic triad will require replacement in 2027 and construction must start by 2019 to make the timeline,” he said in writing. “And yet as best as we can tell this is solely driven by budgetary pressures.”