By John M. Donnelly, CQ Staff

The budget numbers just keep getting worse for the troubled presidential helicopter program.

Pentagon officials quietly notified Congress late last month that a program to build a new fleet of presidential helicopters will cost $1.8 billion more than the Defense Department has publicly acknowledged, congressional aides said Wednesday.

That figure comes on top of a nearly $5 billion hike disclosed a short time earlier. The latest revelation pushes the total cost of developing and procuring 28 new VH-71 helicopters to at least $13 billion, twice the original $6.5 billion estimate in 2005.

As a result, each new helicopter made by Lockheed Martin Corp. would cost $464 million.

The new helicopters’ costs have risen, in part, because program officials underestimated the complexity of modifications designed to carry more people, fly farther and hover longer than aircraft in the current fleet. The new helicopters also must be able to counter surface-to-air missiles. And of course, the president and his entourage could not be without phones, Internet access, printers, fax machines, and video screens able to withstand an electromagnetic pulse from a nuclear blast.

In addition to the cost increases, development is well behind schedule. Delivery of the first batch of helicopters is 18 months behind, with fielding now set for fiscal 2012, according to the new estimates.

The new fleet of Marine One “white tops,” a symbol of presidential authority, had become a focal point in a roiling debate over Defense Department procurement. At a White House forum Feb. 23, the man who lost the presidential election, Sen. John McCain , R-Ariz., publicly confronted President Obama on the issue of overruns in Defense programs and cited the VH-71 in particular.

Obama replied the VH-71 was “an example of the procurement process gone amok, and we’re going to have to fix it,” adding that his current helicopter seemed “perfectly adequate.”

White House Press Secretary Robert Gibbs last month said Obama asked Defense Secretary Robert M. Gates to put the VH-71 program on hold. Obama ordered a review Wednesday of existing federal contracts and new guidance on ways to keep the government from overcharging taxpayers. And he endorsed legislation by McCain that would change the Pentagon’s rules in ways meant to decrease the likelihood the military programs will fall behind schedule and go over budget.

The Navy, which runs the program, would not confirm the higher cost estimate because Gates has not provided a legal certification of its cost or formal justification for the program to Congress. Such certification is required for programs that exceed their original cost estimates by more than 25 percent.