What Changed With the KC-X Evaluation Model?

Shedding some light on the Air Force’s position, Sue Payton, USAF’s acquisition executive, said April 1 that the modifications that the service made to the Integrated Fleet Aerial Refueling Assessment model used during the KC-X source-selection evaluation were instituted “just to make” the scenarios “more realistic.” USAF used the model to score how a fleet of Boeing KC-767 or Northrop Grumman KC-30 tankers would support operations in a high-stress, realistic wartime environment. “At no time were any datasets changed to try to skew or unlevel the playing field,” she told the House Armed Services Committee. Boeing has claimed that the Air Force unfairly tweaked the model so that the larger KC-30 could perform well in the scenarios. One example, Boeing said, was the Air Force’s decision to reduce the minimum ramp clearance between the wingtips of two tankers from 50 feet to 25 feet. But at the same hearing, Gen. Arthur Lichte, Air Mobility Command commander, countered this charge. “In peacetime, we use about 50 feet between aircraft. In wartime—and what we’re using today—it’s 25-foot wingtip clearance. So we decided that’s what we should be,” he said. Overall Payton and Lichte said there were five changes made to the IFARA model. But only one of them “was changed after the RFP was released,” Payton said. “We discovered there was one more parking ramp at Bahrain than the model was allowing as a data input,” she said. “And so that was added for more realism.” Lichte said the other three changes had to do with “ramp utilization with regard to pavement stress,” properly assigning credits to tankers equipped with receptacles to receive gas, and establishing a realistic ground time for the tankers between missions.