A Boeing and U.S. Air Force flight test team recently completed the first aerial refueling of a KC-46A from another KC-46A, according to a Boeing news release.

Each of the two aircraft successfully refueled the other during a four-hour flight that originated and ended at Boeing Field, south of Seattle. The program’s first and second tankers achieved the 1,200 gallon-per-minute maximum fuel offload rate, and transferred a total of 38,100 pounds of fuel over the course of the flight.

The KC-46A is capable of refueling U.S., allied, and coalition military aircraft, as it is capable of employing both flying boom and hose and drogue systems. The tanker can transfer up to 1,200 gallons of fuel per minute via flying boom, while the plane’s three hose and drogue systems, located on both the plane’s wings and along its fuselage centerline, enable the KC-46A to refuel smaller aircraft at transfer rates up to 400 gallons of fuel per minute.

In addition to this latest Pegasus-to-Pegasus refueling, the program’s test aircraft have refueled F-16, F/A-18, AV-8B, C-17, A-10 and KC-10 aircraft over 2,000 flight hours and more than 1,300 contacts.