by Jet Fabara
412th Test Wing Public Affairs
4/26/2013 - EDWARDS AIR FORCE BASE, Calif. (AFNS) -- Known
as "The Mighty War Wagon" of the Air Force, the KC-135 Stratotanker has
proven to be the core aerial refueling capability for the Air Force for
more than 50 years.
With the help of the 418th Flight Test Squadron at Edwards, along with a
multitude of testers, the KC-135 Block 45 test team recently completed a
series of tests in April to help extend the aircraft's service life for
"There are currently 419 KC-135s and 59 KC-10s that enhance the Air
Force's capability to accomplish its primary mission of Global Reach
while providing aerial refueling support to Air Force, Navy, Marine
Corps and allied nation aircraft. These aircraft also provide mission
support including cargo, aeromedical evacuation, personnel transport,
and a variety of other specialized missions," said Maj. John Mikal,
418th FLTS KC-135 Block 45 lead project test pilot. "Increasing the life
expectancy of the current Air Force tanker fleet is critical. Ongoing
upgrade programs help to ensure there is no gap in these mission
capabilities, while the new KC-46 program starts replacing the aging
As part of the KC-135 Block 45 upgrades, Mikal said they included a
digital flight director, a radar altimeter, an electronic engine
instrument display, and Automatic Flight Control System or Autopilot for
Communications, Navigation, Surveillance/Air Traffic Management
(CNS/ATM) requirements in order to maintain global airspace access.
"Maintenance sustainability was another item that was looked at, which
addresses the need to deal with parts that are obsolete, since no one
makes the old parts anymore," said Mikal.
"Commercial off-the-shelf equipment or systems will be used to replace
the existing analog flight director, radio altimeter, autopilot, and 21
cockpit engine instruments with newer digital technology equipment that
will be integrated into the existing avionics."
According to Mikal, the new upgrades will ensure:
- The extension and improvement of mission capability and sustainability of the KC-135 fleet
- The new digital avionics technology integrated into the legacy system will increase safety, efficiency and reliability
- Effective replacement of obsolete components
- The KC-135 meets current and future CNS/ATM requirements, allowing
unrestricted operations in commercial and military airspace throughout
"The Block 45 modification was needed to extend the KC-135 aircraft as a
viable weapon system through fiscal year 2040," added Mikal. "The Block
45 systems mitigate capability gaps and improve overall KC-135
shortcomings in reliability, maintainability and supportability."
At the initial start of the KC-135 Block 45 program, it was originally
estimated that testing would end in March 2011, but the technical
challenge of integrating the new digital systems proved to be very
challenging, according to the test team.
"It took an amazing amount of ingenuity and hard work by the collective
KC-135 Block 45 upgrade team, due to the program experiencing a
two-month stop in test in early 2012 to determine the cause of a
structural coupling event which occurred during flight test," Mikal
said. "While clearing the aerial refueling envelope, the performance of
the new autopilot altitude hold was so good, re-adjustment was required
to improve stability during aerial refueling coupled flight."
Along with the 418th, the massive, multi-year undertaking required
support from more than 90 members to overcome technical hurdles and
prevent the very real threat of program cancellation. Of those included,
individuals were acquired from the 412th Test Wing, 412th Operations
Group, 412th Test and Engineering Group, 773rd Test Squadron, 775th Test
Squadron, 370th Flight Test Squadron, 445th Flight Test Squadron, the
KC-135 Special Programs Office, Rockwell Collins, Air Mobility Command
Test and Evaluation Squadron Detachment 3, AMC Air, Space and
Information Operations (A3), and McConnell Air Force Base, Kan.
"There were only two KC-135 aircrew in the 418th FLTS when the program
started. Eventually, the 418th FLTS KC-135 aircrew numbered four; even
so, Test Operations was largely instrumental in supporting the program
with their KC-135 aircrew," said Mikal.
Most notably though was the Edwards team, which was able to complete the
final testing $200,000 below cost and three weeks ahead of new schedule
through extremely efficient testing and test execution flexibility
despite regular scope changes, priority changes, funding rebaseline,
weather cancellations, maintenance issues, resource
rescheduling/constraints, and the ultimate challenge of addressing the
AR oscillation issue with no additional schedule or funding impacts.
"In the end, the Global Reach Combined Test Force test team proved to be
a pivotal contributor, bringing this challenged program to a successful
completion," added Mikal. "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. Without the KC-135 Block 45, 88-percent of the USAF tanker
assets would eventually be unable to complete their mission."