The last of 50 US Air Force C-5B Galaxy transport aircraft has been delivered back to US Air Force after completing the avionics modernisation programme (AMP) phase of upgrades.

The Galaxy is the US Air Force’s largest airlifter and can carry a cargo payload of six mine-resistant ambush-protected vehicles (MRAPs) or up to five helicopters in addition to troops.

Once modified, the transport aircraft will be called the C-5M Super Galaxy, and will be able to climb higher and faster than current C-5s while carrying more cargo over longer distances and requiring less tanker support.

The AMP modifications, being carried out by Lockheed Martin, include replacement of the existing analogue avionics with a digital avionics suite which utilises a integrated architecture that allows for upgrades.

The entire system is designed to increase safety, ease crew workload and enhance situational awareness.

Lockheed C-5M programme integration office chief Lt. Col. Mike Semo said the aircraft provides a lot more situational awareness, which is very important in a combat zone.

The AMP is the first phase of the two-part modernisation programme, which also includes a reliability enhancement and re-engining programme that began recently.

The first production C-5M is scheduled for redelivery to Dover Air Force Base in September 2010.

A test fleet of three C-5Ms have already been delivered to USAF.