Boeing Defense plans to complete certification flight testing and begin delivering the first KC-46 Pegasus tanker to the U.S. Air Force by late this year. After encountering problems during the program’s developmental phase, the manufacturer expects to deliver the first 18 tankers on a compressed schedule by early next year, initially without their wing aerial refueling pods (WARPs).
“We’re in the tail end of flight-testing on this aircraft,” KC-46 program manager Mike Gibbons informed reporters in May during a media visit to the manufacturer’s facilities at King County International Airport, popularly known as Boeing Field, south of Seattle, Washington.
The engineering and manufacturing development (EMD) contract the Air Force awarded Boeing (Chalet 332/335) in February 2011 called for the manufacturer to deliver the first 18 of 179 planned tankers, nine sets of WARPs and two spare engines by August this year. But problems Boeing encountered in wiring the airliner derivative, a fuel-system contamination mishap, and the need for a refueling boom fix discovered during aerial refueling demonstrations caused the parties to stretch the flight-test phase and compress delivery of the first 18 tankers from the planned 14 months to six months.
While the KC-46 program was meeting cost and performance targets, its schedule presented an ongoing risk due to potential delays Boeing faced in securing design certifications from the Federal Aviation Administration and completing flight-test points, the Government Accountability Office (GAO) reported to the U.S. Congress in March. Earlier this year, the manufacturer and the Air Force modified the schedule to allow Boeing to separately deliver the first 18 aircraft by next February and the WARPs by October 2018—14 months later than originally planned.
The KC-46 is designed to carry 212,299 pounds of fuel—more than half of its maximum takeoff weight. It will offload 1,200 gallons of fuel per minute from a rigid, fly-by-wire refueling boom derived from the boom used on the KC-10 Extender. The tanker’s centerline hose-and-drogue system and wingtip WARPs systems supplied by Cobham (Hall 2b E156) each offload fuel at 400 gallons per minute.
Program executives expected the WARPs would be the last subsystem to receive design approval from the FAA. “According to Boeing officials, the company and its WARP supplier had underestimated the level of design drawing details the Federal Aviation Administration needed to review to determine that the parts conformed to the approved design,” the GAO stated. “According to these officials, the WARP supplier has been negotiating with its various sub-tier suppliers over the past three years for the necessary design documentation.” Executives estimated the FAA will approve the pod design in July.
Boeing faced completing 1,700 test points per month on average between February and September, a level more than double what it had completed in the preceding 11 months, the GAO said.
Briefing reporters on the program’s status on May 16, Gibbons was confident the manufacturer will meet the current schedule. The program was 90 percent complete with the requirements of obtaining an amended type certificate from the FAA for the 767-2C baseline freighter with tanker-system provisions, and 60 percent complete toward securing a supplemental type certificate for the full KC-46 tanker. The Air Force will then certify airworthiness of the military platform.
“The plan this year is just to complete that certification of the aircraft with the FAA,” then acquire Air Force certification, Gibbons said. “The FAA is very committed to this.”
Similarly, Gibbons said Boeing should complete all required flight-test points on time. “We don’t expect to have any changes that would require modifications, so the increase in test-point completion will pick up quite significantly,” he said. “We’ve got the test points all laid out specifically and we expect to complete that testing this year.”
At the time Boeing was testing six aircraft, including four EMD and two low-rate initial production (LRIP) tankers. One of the LRIP aircraft was undergoing electromagnetic effects testing at Edwards Air Force Base, California.
During a walk-around of the EMD 4 tanker at Boeing Field, KC-46 chief pilot Ron “Taco” Johnston described some of the interesting features of the Pegasus; among them are Honeywell (Chalet 104) infrared lights mounted on its nose landing gear to support night operations in total darkness, and pilot director lights along the bottom of its forward fuselage to guide receiver pilots at night.
Test pilots are taking advantage of the automation provided by the tanker’s Boeing 787 Dreamliner-derived flight deck by using the autopilot and autothrottle to control the jet, giving them more time to monitor tactical communications and self-protection systems, Johnston said. The KC-46 is fitted with the Raytheon (Chalet 294) AN/ALR-69A(V) radar warning receiver and Northrop Grumman AN/AAQ-24(V) Large Aircraft Infrared Countermeasures system.
In a standalone trailer Boeing takes on the road to conferences, Sean Martin, the KC-46 program’s chief air refueling officer, described the tanker’s air refueling operator station, located behind the flight deck. The station features the Rockwell Collins (Chalet 313) Remote Vision System, which makes use of visible and long-wave infrared stereoscopic cameras to support both day and night aerial refueling. “The boom flys phenomenally,” Martin reported. “Our boom from day one has been able to trail out at Level 1 handling qualities at 25 degrees roll left and right and up to 20 degrees and down to 30 degrees with no instability.”
The Air Force in January awarded Boeing a third LRIP contract, bringing to 34 the number of production tankers the service had ordered. As of late May, there were 20 aircraft cycling through production at Boeing’s Everett, Washington, location.
The plan is to meet the latest delivery schedule, Gibbons said. “The development is behind the original plan, but what we’ve not slowed down on is production overall,” he argued. “Our production is still going at the same rate as the original plan. Once development is complete, we will start delivering (tankers) and in very short order the U.S. Air Force will be back to the original plan.”