In constant use: The Mobile Microwave Landing System at North Field

CHARLESTON AIR FORCE BASE, S.C. (USTCNS) --- Sitting near the runway at North Auxiliary Airfield, S.C., is a piece of equipment that looks like an unmanned NASA space probe.

But the real purpose of the equipment is earthly in nature. Known as the Mobile Microwave Landing System, it provides C-17 and C-130 pilots information about the distance to the landing end of the runway.

It can provide information to pilots about azimuth, horizontal, vertical course, and glide slope guidance, as well. MMLS also allows pilots to vary their angle of approach to the airfield.

The benefit of MMLS is that it provides a computed approach for pilots, according to Tech. Sgt. Eric Lentner, a meteorological and navigational aid technician with the 437th Mission Systems Flight, part of the 437th Communications Squadron.

"It's easy to deal with," said Capt. John Russi, a pilot and flight examiner with the 17th Airlift Squadron. "We just dial in the frequency and it comes up for us. It's very simple."

Although MMLS is designed to be mobile, it has become a permanent fixture at North Field, according to Tech. Sgt. Joel Obman, also a meteorological and navigational aid technician with the 437th MSF.

MMLS is constantly operating at North Field, but doesn't require a technician to be permanently on hand to run it. Obman and Lentner travel to North Field when MMLS is not operating properly.

"We have test equipment to see on the ground what they (pilots) see in the air," Obman said.

"Once in a while, they'll (pilots) call us to change angles," Lentner added.

Because it is operating constantly, the North Field MMLS set -up is unusual Lentner said. For this reason, cement pads and permanent power and communications lines were installed.

While it includes an azimuth antenna, an elevation antenna, a distance measuring equipment antenna and a monitor antenna, MMLS is designed to be set up quickly by two or three communications technicians.

Obman said a site survey usually takes half a day.

"The initial set up is for us to go into a remote location, set it up in a short amount of time and allow aircraft to do instrument approaches to an airfield, where it would take a lot longer to get a fixed system installed, " Obman explained.

North Field is an ideal location to train with MMLS because the air traffic is not as heavy as Charleston AFB, where a steady stream of military and commercial aircraft flows in and out, according to Russi.

"What we have to do here is train the pilots on MMLS approaches, so that they will be prepared when they go into austere locations around the world," Obman said.

MMLS has already been used in real-world contingency situations, such as Bosnia and Albania, and the system is permanently located at airfields such as Ramstein AB, Germany.

"The MMLS is good practice for us because, in a contingency situation, that's what they would set up for us," Russi said. "To practice MMLS at North Field with a short field runway is really valuable training."

MMLS is also used at McChord AFB, Wash., Pope AFB, N.C., and Hurlburt Field, Fla. (FROM AIR MOBILITY COMMAND PUBLIC AFFAIRS).