The KC-135 Stratotanker and C-130 Hercules -- which have been in the Air Force’s inventory since the 1950s -- have “held up very well during” operations in the Middle East, Maj. Hall Sebren, chief of the Logistics Operations Division at the Combined Air Operations Center in Southwest Asia, told Inside the Air Force in a Nov. 24 e-mail.

Since fiscal year 2000, the C-130’s overall mission capability rate -- meaning the aircraft is cleared to carry out all possible tasks -- has risen from 69.5 percent to 75.9 percent in FY-06, according to an Air Mobility Command chart. A service spokesman provided the chart in response to an inquiry about the mission capability rates.

Specifically, the C-130E model has improved 62.8 percent to 75.8 percent while the C-130H model fell slightly from 76.8 percent to 75.9 percent, the chart states.

As for the KC-135, its mission capability rate has improved from 81.8 percent in FY-00 to 84.5 percent in FY-06, according to the document. The KC-135R model rate has risen from 82.6 percent to 84.4 percent and the KC-135T model has improved from 79.6 percent to 85 percent.

“Our KC-135 air refueling aircraft have held up very well during this rotation,” Sebren said.

The Stratotanker’s mission capability rate -- specifically in Iraq and Afghanistan -- have been “above normal operating standards” during combat operations in Southwest Asia, the air logistics chief said. He credited the performance of maintenance personnel in theater for the higher reliability numbers.

“To put things in perspective, we are flying twice the [number] of sorties and nearly four times the [number] of hours on the aircraft in theater as compared to the stateside norm,” he said. “As always, there have been some minor bumps in the road, which can be expected from a fleet with an average age of 46.2 years, but nothing that would be classified as systemic,” he added.

In theater, Sebren said the KC-135’s mission capability rate is more than 80 percent and the C-130’s rate is “slightly higher.”

The “C-130 aircraft are one of the key workhorse airframes in theater, operating missions ranging from aeromedical evacuation to cargo movements to electronic reconnaissance to” air drops, Sebren said. “The airframes get a lot of flying hours working grueling missions” in Iraq and Afghanistan and have “proved to be both reliable and versatile.”

Despite the overall rise in the past six years, the Stratotanker’s and Hercules’ highest mission capability rates came in FY-03. That year, the KC-135 achieved an 85.3 percent rate and the C-130 achieved a 78.9 percent rate, according to the chart.

The Air Force operates more than 500 Stratotankers and 500 Hercules, according to a service fact sheets.

The KC-135 and C-130 are not the only aircraft with their mission capability rates on the rise. In November 2006, ITAF first reported mission capability rates for the B-2 bomber had risen five percent. Officials at Air Combat Command credited a new spray-on synthetic, low-observable coating applied to the aircrafts’ fuselages, for raising the mission capability rates, a spokeswoman at the command said.

By applying the stealthy material onto the bomber’s airframe, maintenance personnel can remove surface access panels on the airplane and repair the subsystems underneath, while maintaining the B-2’s low observability envelope, she added.

Despite the improvement, the Spirit’s mission capability rates remain far below the Stratotanker and Hercules. Its full mission capable rates since fiscal year 2000 remained below the Air Force standard of 51 percent. The fleet averaged 31 percent in FY-05, according to an April 13 Pentagon report. That figure represented a 12 percent drop from FY-04, when the B-2 was fully mission ready 43 percent of the time.