Boeing’s KC-46 tanker programme has successfully completed its Federal Aviation Administration (FAA) Supplemental Type Certificate (STC) fuel on-load testing.

During the air refuelling mission testing performed recently, a KC-46A Pegasus multi-role tanker transferred 146,000lb of fuel to a second KC-46.

The refuelling flight between the two KC-46 tankers, which took off and landed at Boeing Field, south of Seattle, US, lasted for three hours and 48 minutes.

The mission also saw the pair achieve the maximum fuel off-load rate of 1,200 gallons per minute, Boeing stated.

As part of the programme’s FAA STC testing, the KC-46 aircraft also proved the capability to receive fuel from other tankers such as KC-135 and KC-10 aircraft.

The KC-46 tankers completed a total of 68 contacts with refuelling aircraft and took on 540,600lb of fuel during these tests.

“The mission also saw the pair achieve the maximum fuel off-load rate of 1,200 gallons per minute.”

A test team formed by Boeing and the US Air Force (USAF) is currently working to complete the overall STC testing that covers the evaluation of the military systems installed on the KC-46 tanker.

Designed based on the KC-767 refuelling aircraft, the KC-46 is being manufactured by Boeing under a contract with the USAF.

The aircraft is equipped with a boom system to transfer up to 1,200 gallons of fuel per minute and the hose and drogue systems to refuel smaller aircraft with up to 400 gallons of fuel per minute.

After entering operational service, the KC-46 will use its boom and hose and drogue systems to refuel the US, allied and coalition military aircraft.

The KC-46 test aircraft have, to date, completed 2,700 flight hours and over 2,500 contacts during refuelling flights with the F-16, F/A-18, AV-8B, C-17, A-10, KC-10 and KC-46 aircraft.