The US Air Force (USAF) has completed evaluations of the KC-135 Stratotanker Block 45 upgrades, which are designed to extend the aircraft’s service life to 2040, at Edwards Air Force Base in California, US.
Carried out by the KC-135 Block 45 test team with support from the 418th Flight Test Squadron, the testing fully validated all Block 45 systems that mitigate capability gaps and enhance the overall KC-135 shortcomings in reliability, maintainability and supportability domains.
The upgrade involved integration of a digital flight director, a radar altimeter, an electronic engine instrument display, as well as an automatic flight control system or autopilot to help the aircraft address communications, navigation, and surveillance/air traffic management (CNS/ATM) requirements that enable unrestricted operations in global airspace.
418th FLTS KC-135 Block 45 lead project test pilot major John Mikal said increasing the life expectancy of the existing tanker fleet is "critical" and will enable the air force to accomplish its primary mission of global reach.
”Ongoing upgrade programs help to ensure there is no gap in these mission capabilities, while the new KC-46 programme starts replacing the aging KC-135 fleet," Mikal added.
"Successful completion of this program has secured the opportunity to field Block 45 to the KC-135 fleet, while preventing the otherwise inevitable reduction in overall mission effectiveness due to avionics obsolescence and CNS/ATM airspace access issues.”
Replacing the existing analogue flight director, radio altimeter, autopilot, and 21 cockpit engine instruments with the commercial off-the-shelf and newer digital technology equipment, the programme is also believed to have addressed maintenance sustainability issues.
Originally scheduled to complete in March 2011, the testing was however delayed as the KC-135 Block 45 upgrade team faced challenges when incorporating the new digital systems.
As well providing USAF with core aerial refuelling capability for more than 50 years, the KC-135 tanker is operated for cargo and personnel transport, aeromedical evacuation, and an array of other specialised missions.
Image: A USAF KC-135 Stratotanker aircraft stationed at Selfridge Air National Guard Base in Michigan, US. Photo: US Air Force photo by John Swanson/Released.