Several hundred Air Force warplanes are being equipped with a variant
of an Army radio system that gives air crews access to the same
tactical picture that the commanders see on the ground.
The Army radio is the EPLRS (enhanced position location reporting
system). Ground vehicles equipped with EPLRS form a network that
distributes data around the battlefield, such as the locations of
friendly and enemy forces.
Air Force F-16 and A-10 fighter aircraft are using the EPLRS situational
awareness data link (SADL) to connect into the Army’s tactical
Internet, said Maj. Gen. Steven W. Boutelle, program executive officer
for command, control and communications. “It works,”
he told a conference of the Association of the U.S. Army in Fort
Lauderdale, Fla. The idea is for both services to have a “common
operating picture” and to not have to rely exclusively on
With SADL, the aircraft “nets up with the ground community”
for close air support missions, so they can look on the ground for
friendly forces, explained John Martin, an engineer with Raytheon
“It enhances the capability of the air guys to go play with
the ground guys,” Martin said. It also could help prevent
fratricide. The SADL radio is integrated with aircraft avionics
over the 1553 multiplex data bus.
The F-16s and A-10s that are receiving the SADL system primarily
are from guard and reserve units. “The pilots can see where
the target is,” Martin said. SADL gives them a ground picture
and allows them to monitor the immediate air picture.
The SADL is much like the ground EPLRS, with slightly different
firmware in the radio. With the turn of a switch, the radio can
convert from SADL to EPLRS. More than 700 have been built for F-16s
The airborne version of EPLRS initially had not been planned for
the Air Force, but for Army aviation, “even though we had
a lot of problems breaking into the Army aviation world,”
Air Force warplanes typically rely on the Link 16 tactical data
network. But many guard and reserve platforms are not going to get
Link 16 terminals because they are expensive, said Martin.
A SADL terminal is in the $30,000 to $50,000 price range. A Link
16 terminal runs about $200,000.
SADL provides a “gateway” to Link 16 networks, said
Richard E. Hitt Jr., director of business development at Raytheon.
SADL runs in a different portion of the frequency spectrum than
Link 16. “If you have a Link 16 radio next to a SADL radio,
the gateway software can communicate with both radios and move data
back and forth between the two networks,” he explained. A
SADL radio can distribute the data that it pulls from the Link 16
network to other SADL radios, Hitt said. “Those users who
can only afford SADL can take advantage of the fact that there is
Link 16 in the area.
“We just need one SADL radio in the tactical area, connected
to one Link 16 radio in the network and, bingo, we have two networks