Over 1,100 aircraft out of action as Israel, Japan and Saudi Arabia follow suit

US Air Force pleas for funds to replace its ageing aircraft took on a new edge with the indefinite grounding of its fleet of almost 700 Boeing F-15s following a 2 November crash suspected to have been caused by structural failure.

F-15 operators Israel (95 aircraft), Japan (160) and Saudi Arabia (145) followed suit after the USAF suspended all non-essential flights. US F-15E strike fighters based in Iraq and Afghanistan and F-15C interceptors assigned to North American air defence remain on ground alert to fly if required, although their missions have been taken over by other US and allied aircraft. Boeing confirms that it is "providing engineering support" to the USAF during its investigation.

The Missouri Air National Guard F-15C, built in 1980, was engaged in air-combat training with three other F-15s when it crashed. The pilot ejected, sustaining minor injuries. Reports that the aircraft separated aft of the cockpit have not been not confirmed by the USAF, but the aircraft's forward fuselage is not discernable in video of wreckage site.

In April 2002, an F-15C crashed into the Gulf of Mexico after the leading edge of its left vertical stabiliser broke off during a high-speed dive to Mach 1.97. The F-15's leading edge and upper aft portion of the vertical stabilisers are being replaced during depot maintenance, and the USAF says it has completed 463 of its 664 aircraft - including the one involved in the Missouri accident, which was repaired in August 2003.

The air force plans to keep the F-15C in service until 2025 and its newer F-15Es until 2035, and recently awarded contracts to upgrade up to 179 Cs and all 224 Es with Raytheon's APG-63(V)4 active electronically scanned array radars.

Lockheed Martin's F-22 was designed to replace the F-15, but production is planned to end in 2011 after providing just 183 of the 381 aircraft the USAF says it needs. The service has requested Department of Defense approval to buy a further 20 F-22As, which would extend production by a year, but require more than $4.4 billion in additional funding.

Source: Flight International