The KC-46A tanker, which Boeing [BA] is developing for the U.S. Air Force, has achieved a key milestone by finishing flight tests needed to obtain its second of two airworthiness certifications from the Federal Aviation Administration (FAA), the company announced April 26.

A KC-46 communicating with and refueling a C-17 Globemaster III transport plane marked the last in a series of flights required to achieve a supplemental type certificate (STC) from the FAA, the company said. Boeing will now submit the test data to the agency in hopes of obtaining the STC, which would approve the military systems that make the modified 767 jetliner a tanker. 

A KC-46 tanker refuels an F/A-18 fighter during testing. (Boeing photo)
A KC-46 tanker refuels an F/A-18 fighter during testing. (Boeing photo)

STC flights showed that the KC-46 can refuel several kinds of aircraft, as well as receive fuel from other tankers, Boeing said. The tests also checked out the KC-46’s avionics, defensive systems and lighting.

The KC-46 received its first FAA airworthiness certification, an amended type certificate (ATC), last year (Defense Daily, Dec. 21, 2017). The ATC verified that the aircraft, without its aerial refueling system installed, is safe and reliable.

The program continues to work toward obtaining a military type certificate, an Air Force airworthiness certification.

The STC flight-test announcement was a boost for the delay-plagued program. The Air Force, which originally hoped to take delivery of the first aircraft in early 2016, now expects to receive it in late 2018 (Defense Daily, March 7).

Lawmakers are urging the program to overcome its turbulent history. Rep. Rob Wittman (R-Va.), chairman of the House Armed Services Committee’s seapower and projection forces panel, said April 26 that the Air Force “should lean forward” to accelerate deliveries and that Boeing should “rapidly correct” remaining problems.

The Air Force recently revealed that two of the plane’s systems — the Centerline Drogue System (CDS) and the Remote Vision System (RVS) – are not yet meeting performance requirements (Defense Daily, March 15).

The Air Force awarded a KC-46A development contract to Boeing in 2011. The service plans to buy 179 KC-46As to replace some of its aging tankers.