The US Air Force plans to spend $2.8 billion to keep old combat aircraft in the air because of major delays with the new F-35 fighter jet program, top officials said Friday.

With the production schedule of the F-35 jet repeatedly postponed due to technical problems, the Pentagon will upgrade 350 aging F-16 fighters to fill the gap in the fleet, Air Force leaders told reporters.

"The issue with respect to F-35 is that obviously the planes are not delivering as quickly as originally anticipated," said General Norton Schwartz, the Air Force chief of staff.

As a result, the Air Force needed "to posture the legacy force to make sure that we retain the capabilities we need until the F-35 delivers in numbers," he said.

The F-35 Joint Strike Fighter, manufactured by Lockheed Martin, is touted as the backbone of America's future air fleet but an ambitious production timeline has unraveled due to technical headaches that emerged in initial flight tests.

Officials discussed extending the service life of the F-16s as they unveiled details of the Air Force's proposed budget for fiscal year 2013.

Despite production delays for the F-35, Air Force Secretary Michael Donley insisted the government remained fully committed to the program and to purchasing a total of 2,443 of the aircraft as planned.

"This is a must-do for our armed forces. It's the future of the fighter force, not only for the Air Force, Navy and Marine Corps, but also about 12 other international partners as well," he said.

At an estimated $385 billion, the F-35 is the Pentagon's most expensive weapons program. The military had hoped to have 423 of the F-35 fighters built between 2013 and 2017 but has had to slash the number down to 244.

US Air Force to cut fleet in budget squeeze: officials
Washington (AFP) Feb 3, 2012 - The US Air Force is proposing to cut 286 aircraft from its fleet, officials said Friday, as the Pentagon seeks to rein in defense spending after a decade of massive budgets.

Air Force chiefs unveiled the outlines of a proposed budget for 2013 that included retiring some older aircraft and eliminating 9,900 positions.

With the Pentagon looking to scale back projected spending by $487 billion over the next decade, the Air Force cutbacks represented "tough choices," said Air Force Secretary Michael Donley.

"This is hard but manageable," he said, adding that deeper cuts could not be sustained without damaging the country's military might and unrivaled air power.

The proposals for fiscal year 2013 include retiring 123 fighters, 133 transport aircraft and 30 surveillance planes, he said.

The bulk of the fighters to be cut are 102 A-10 warplanes, designed as "tank killers" to back up ground forces. The aircraft, which dates back to the 1970s, saw action in Libya, Iraq and previous conflicts.

But Donley said there was no longer money for "niche fleets" and that the Air Force had opted to devote limited funds to more versatile aircraft.

Despite the cutbacks, there would still be 246 A-10s remaining in service along with other aircraft capable of providing close air support for troops on the ground, said General Norton Schwartz, Air Force chief of staff.

"The bottom line is, as remarkable an airplane as the A-10 is, it isn't the only machine that does close air support," he said.

Officials also said the A-10 "Warthog" -- which came into service in the 1970s -- appeared out of place under a new US strategy more focused on the Asia-Pacific region, where the American military does not anticipate having to take out tanks in a massive ground war.

"The Air Force is retiring planes that don't fit into the Asia-Pacific strategy," said Loren Thompson of the Lexington Institute, which has ties to defense contractors.

The revised US strategy unveiled last month calls for a "leaner" force more focused on Asia, amid concern over China's growing economic and military power.

Despite fiscal pressures, the Air Force had maintained ample funding for key priorities, Donley said, including support for bomber forces, the new F-35 fighter, unmanned aircraft, satellites and cyber programs.

President Barack Obama has raised the possibility of streamlining the nuclear force with "smaller numbers" but the White House has yet to make a final decision, he said.

The proposed budget envisages cutting 9,900 personnel on active duty as well as those in the Air National Guard and reserves, officials said.

The Air Force currently has more than 500,000 service members, including airmen in the guard and reserves. By next year, it will be the smallest force since the US Air Force was created in 1947.