Gov. Rendell announced a deal with the Air Force yesterday that could prevent the nearly 1,100 acres at Willow Grove Naval Air Station from being abandoned in the next four years and eventually developed.

The state wants to turn the base into a sort of combination military facility and civilian emergency preparedness center, with the capability of responding to a local 9/11 or Hurricane Katrina.

With Air Force cooperation, the state hopes to take control of the base by 2011 and lease its facilities for any number of uses, including the headquarters of the Pennsylvania Army National Guard's new 56th Stryker Brigade.

The agreement will not save the 913th Airlift Wing of the Air Force Reserve from being shut down, as scheduled, on Sept. 29. Nor will it stop Navy, Marine Corps and National Guard units now at the base from being moved, closed, or stripped of their airplanes under Pentagon plans to scale back military facilities across the country.

But the deal appears to preserve Willow Grove's 8,000-foot runway and make sure that the vast acreage along Route 611 in Montgomery County is not turned into a shopping mall or housing complex.

"I think this represents what we were fighting for when we were trying to save the base," said Ed Ebenbach, a board member of the Suburban Chamber of Commerce, based in Willow Grove.

He said, at first glance, he was "pretty enthusiastic" about the plan.

The governor yesterday released a letter from Michael W. Wynne, secretary of the Air Force, in which Wynne agreed to a Rendell proposal to turn Willow Grove into something new called a joint interagency installation.

This would allow the base to continue to be home to some small military units that plan to remain while opening the rest of the site to agencies such as the U.S. Department of Homeland Security and the Federal Aviation Administration.

The Air Force, which occupies 162 acres at the Navy-run base, will attempt to acquire all of it from the Navy. If successful, it will lease the entire site to the state.

The state's $10-million-a-year cost of running the facility would mostly be offset by lease payments it gets from federal agencies, the state said.

All of this needs approval from the Navy and the Department of Defense, but state officials said they were very optimistic that the biggest hurdle had been crossed with Wynne's acceptance of the plan.

"This is a significant and historic development for Willow Grove and for the commonwealth," Rendell said in a statement.

Willow Grove has more than 5,000 military and civilian employees, but units already are being phased out.

The 913th Airlift Wing, the first major unit scheduled to go, has been holding job fairs for civilian workers and trying to place reservists in jobs at other air bases.

Maj. Gen. Jessica Wright, the state adjutant general, said the new plans for Willow Grove would not prevent the loss of current military units on the Pentagon's hit list.

But she said the proposed new uses for the base could ensure that it remains a vibrant facility and a robust contributor to the area economy.

Wright said the new plan could even help the state in its drawn-out effort to block the Air Force from stripping the 111th Fighter Wing, a Pennsylvania Air National Guard unit, of its 15 A-10 Warthogs.

Air Force plans call for the planes to be parceled out to units at three other out-of-state air bases by 2010. The Air Force also wanted to shut down the fighter wing, but the state successfully blocked that in a lawsuit. The case is now on appeal in the U.S. Third Circuit Court of Appeals in Philadelphia.

Wright said the Air Force's argument for taking away the planes was mainly that the runway was going to be shut down. But now that it may not, the planes could be able to stay, she said.

If the 111th cannot keep its Warthogs, maybe it could be given another type of plane to fly, she said.

"We have to get a new mission for that wing," she said. "Now we hope we will be successful."

Art Stephens, Rendell's deputy chief of staff, said Willow Grove's long runway is too precious a resource to abandon or lose to development.

He said it could be used to bring emergency supplies into the Philadelphia region in case of natural or manmade disaster.

"We've had over a dozen state and federal agencies that have expressed an interest in Willow Grove as an emergency preparedness location," Stephens said.

Rendell credited the state's congressional delegation with promoting the deal in Washington. He cited Republican U.S. Sen. Arlen Specter and Democratic Sen. Bob Casey, along with Democratic Rep. Allyson Schwartz, whose 13th District includes Willow Grove.

Rendell added special kudos for a Democratic congressman from Johnstown.

"In particular, I must thank Congressman John Murtha," he said.

Murtha happens to be chairman of the defense appropriations subcommittee in the House. The next time the Air Force needs funding for anything, it must go through him.

Contact staff writer Tom Infield at 610-313-8205 or tinfield@phillynews.com.