WASHINGTON, Dec 11 (Reuters) - Lockheed Martin Corp. said it was still working toward a first flight of the F-35 Joint Strike Fighter, possibly this week, but the maiden flight would not come on Monday.
Lockheed spokesman John Smith said the plane successfully completed a low speed taxi test last Thursday and received flight certification on Friday.
At a projected $276.5 billion, the planned family of radar-evading warplanes represents the Pentagon's priciest planned purchase, with more than 2,400 aircraft by 2027 for the U.S. Air Force, Navy and Marine Corps.
Before its first flight, the F-35 still needs to pass medium and high speed taxi tests. Rainy weather, wind and other factors delayed those tests at Lockheed's Fort Worth, Texas test site this past week, company and program officials said.
The supersonic, multirole aircraft's development has been co-financed by eight international partners -- Britain, Italy, Netherlands, Turkey, Canada, Australia, Denmark and Norway.
Smith said it was unclear exactly when those tests would now be conducted, making it difficult to predict the timing of the F-35's first flight. But he stressed that no unexpected problems had emerged.
"Everything's pretty much going along as predicted. When all the conditions line up, that's when they'll fly," he said.
Last week, Marine Brig. Gen. David Heinz, deputy director of the F-35 program, told Reuters the first flight of the next-generation fighter jet could come as early as Monday after a series of tests on the ground.
"We expect it to be this week," program spokeswoman Kathy Crawford said. "Technically there are no issues at this point."
Meanwhile, Pentagon officials have told the Navy and Air Force to fully fund the F-35 program in fiscal year 2008, according to defense analyst Loren Thompson of the Lexington Institute and a senior defense official.
If the White House agrees, the Pentagon will order six Air Force versions of the plane and six short-takeoff and vertical landing variants in fiscal 2008, said the official, who asked not to be named.
The Navy and Marine Corps had proposed cutting more than $1 billion of F-35 orders between 2008 and 2013, which would have delayed the airplane's initial operating capability.
"Now the program is back on track," said Thompson, who has close ties to Pentagon and Air force officials..
The single-engine F-35 is to replace aging F-16s, F/A-18 Hornets and a range of other fighter and strike aircraft for the United States and its allies over the next 30 years.