A panel of US senators has voted to remove a five-year-old legal ban on retiring the US Air Force's 59 Lockheed Martin C-5As, perhaps paving the way for even greater orders for Boeing C-17s.

The US Senate defence subcommittee for appropriations also voted to add 10 C-17s to the fiscal year 2010 budget, on top of another eight C-17s already ordered under the fiscal 2009 supplemental spending bill for "overseas contingency operations".

The USAF stopped requesting funds for more C-17s after ordering 180 aircraft. But the US Congress has already stepped in to order 25 more C-17s, and, if the current legislations passes, the USAF's total orders would rise to 223 C-17s. Foreign customers have also extended Boeing's production line, with six countries ordering about 20 C-17s since 2007.

USAF Boeing C-17
 © USAF/Airman 1st class Brett Clashman

The USAF is buying the C-17 to replace more than 300 retired Lockheed C-141 airlifters. In the past, the Air Mobility Command has expressed interest in buying as many as 305 C-17s, although the USAF's requirement remains locked at 180.

Last year, US Air Force Chief of Staff Gen Norton Schwartz told legislators that the USAF does not need more C-17s unless the C-5As are allowed to be retired.

Since 2004, Congress has made it illegal for the USAF to retire any C-5As. The retirement ban was championed by the late Senator Ted Kennedy, who died on 25 August, and former Senator Joe Biden, who was elected vice-president last November.

With both the C-5A's main supporters no longer in the Senate, their colleagues moved swiftly to lift the five-year-old retirement ban.

Senator Daniel Inouye, chairman of the appropriators' defence subcommittee, said in a statement that the C-5A is "ageing, hard to maintain, and often broken".

Inouye also called on military planners to keep C-17 production alive with even further orders. "We expect that in re-examining its airlift fleet the Department of Defense will eventually conclude that purchasing additional C-17s and maintaining the strategic asset of a hot airlift production line is the right solution," he says.

The USAF plans to finish modifying all 59 C-5As with the avionics modernisation programme, and possibly upgrade some to the C-5M standard with the Reliability Enhancement and Re-engining Programme. But the lifting of the retirement ban could mean that some or all of the C-5A fleet could be removed from operational service.

The USAF also plans to upgrade all 52 C-5B/C airlifters to the C-5M standard, which includes new General Electric CF6-80C2 engines to replace GE TF33s.

Source: Flight International