The US Air Force (USAF) is set to conduct developmental testing of the newly acquired MH-139A Grey Wolf test aircraft.

The milestone achievement comes after Boeing secured the final Federal Aviation Administration Supplemental Type Certification process.

This certification is required by aircraft to achieve Military Flight Release.

With the latest progress, the USAF can now conduct an evaluation of MH-139A’s critical military capabilities to further move the programme towards Milestone C.

The ownership of the four MH-139A helicopters was accepted by the USAF earlier in mid-August this year.

Before accepting the ownership, pilots from the Air Force Global Strike Command’s (AFGSC) Detachment 7 and 413th Flight Test Squadron carried out extensive acceptance tests on the helicopters.

AFGSC is the operational capability requirements sponsor and the lead command.

MH-139 Test Detachment 7 MH-139 Standardisation and Evaluations chief lieutenant colonel Josh Hallford said: “Leonardo’s 139 helicopters have an impressive pedigree of performance in multiple missions in civil, public and military domains.

“The built-in system redundancies and physical performance of aircraft show great potential for improving on a myriad of missions that have been covered by venerable Huey for so long.”

The USAF plans to acquire as many as 80 MH-139A helicopters, training devices and support equipment.

The MH-139A Grey Wolf fleet will replace the USAF’s existing UH-1N aircraft fleet.

The new fleet is expected to provide a significant capability increase in payload, range, speed, endurance and survivability.

Furthermore, the MH-139A fleet will offer vertical airlift, as well as support the USAF’s four Major Commands and other operating agencies.

It includes Air Force Materiel Command, AFGSC, Air Education and Training Command, Air Force District of Washington and Air Force Reserve Command.