Winter weather keeps Airmen busy doing the math for aircraft safety

by Airman 1st Class Kyle Johnson
JBER Public Affairs

11/20/2015 - JOINT BASE ELMENDORF-RICHARDSON, Alaska -- Alaska's weather brings all kinds of perils to motorists. When the snow first came this year, road conditions put more than 80 cars in the ditches around Anchorage after just one day of snowfall.

The risks are real - and even more so when they endanger military aircraft.

That's why the Airfield Management Flight is on the runway all day doing brake checks, said Senior Airman Jerred Johnson, an Airfield Management operations supervisor with the 3rd Operations Support Squadron.

"We get up to a speed of 20 to 30 miles an hour, and we stomp on the brakes to induce a skid; then the decelerometer kicks out a number: our friction reading," Johnson said. "We combine our friction measurement with our surface condition to get the road condition reading."

A decelerometer is a device in their trucks that allows them to judge how long it takes to stop. After performing a series of complex mathematics, the device condenses this information into a friction measurement.

"We give that to the pilots and - based on their training orders and that measurement - they determine if they are able to taxi and take off," Johnson said.

While being employed by the military to brake-check the snow-covered flightline over and over again throughout the day may sound like a care-free joy ride in a government vehicle, it is anything but.

"You need to know what all your priorities are, what time is this aircraft taking off, what parking spot is it on, what's its taxi route, what are its minimums, and keep an eye on the weather - is it going to start snowing in the next 30 minutes?" Johnson said. "If so, those F-22 [Raptors] that are in the air may have to divert to a different location if we can't keep the runway conditions within their minimum."

Because each aircraft has different features, landing gear and weight, each aircraft also has a different tolerance for surface conditions on the runway.

"Every aircraft in their training order has a set number that says it can take off with a certain runway condition, which are expressed as numbers," Johnson said. "A C-17 [Globemaster III] has reverse thrust, so its number might be lower, versus a fighter aircraft that needs a higher number to land because he's coming in a lot faster and doesn't have reverse thrust."

By establishing a measurable value to surface conditions, the airfield management team is able to quickly and efficiently determine which aircraft can use the flightline safely and where. This is further complicated by the fact the runway is actually composed of different types of pavement.

One runway has concrete on one end, but asphalt on the other. The concrete is going to be slicker than the asphalt, but both need to be within a certain aircraft's minimum friction measurement to allow for a safe landing.

To ensure this happens, the runway is constantly maintained to the highest safety standards, and the airfield management flight coordinates which sections need attention and when.

"All the asphalt and concrete is grooved to help with friction, and every year the Air Force Flight Standards Agency comes out and does a friction evaluation of the runway," Johnson said. "We work in conjunction with the snow removal teams. We let them know what priorities certain areas are, what time aircraft are taking off, and what their taxi route is."

Much like the air traffic controllers have a tower they use to coordinate the direction of aircraft coming and going on the flightline, the airfield management team coordinates ground efforts to make sure the right runways are ready at the right time.

"Our first priority is ensuring the runway numbers are constantly kept up to the minimum for the Combat Alert Cell so they can launch, the [Airborne Warning And Control Systems] can launch, and our rescue aircraft can take off at any time," Johnson said.

On a normal day, two Airmen coordinate more than 70 civil engineer troops all around the flightline while planes come and go, each with their own unique runway requirements.

"Usually the operations supervisor is out doing the skid checks, and the operations coordinator is the one inside answering phones, plugging the information in, maintaining logs, taking requests. All snow removal requests for the airfield are coordinated through us, so we can prioritize them," Johnson explained. "Otherwise everyone will just be calling roads and ground and saying 'we need this' and 'we need that.' It would be a nightmare."

Every plane that takes off or lands safely is a testament to these Airmen's dedication to excellence, but there can always be improvement. This holiday season, the Air Force is going to bring them some new toys.

"We're getting everything set up to be wireless-capable; there's going to be an antenna on the truck and an antenna on this building and it's going to automatically update on a stand-alone computer and the tower will be able to get those numbers real-time," Johnson said.

Currently, they write down all their measurements and update a variety of different databases, which the tower then taps into to get the friction measurements the pilots need to determine their safety while taxiing or inbound to land, Johnson said.

"We used to use an older decelerometer, and we just got some new ones which are definitely state of the art," Johnson said. "It's the only one I know of that's capable of doing the wireless transmissions."

The new equipment is another example of innovation applied across the Air Force to make the mission more efficient.

"Those numbers are crucial. We may have to take off very quickly, and that information is important, because in 15 minutes, the weather can change completely," said Air Force Capt. Robert Crespo, chief of squadron training at the 962nd Airborne Air Control Squadron. "Those 15 minutes can determine whether we are grounded or taking off."

"No aircraft can fly without first getting a friction measurement," Johnson said. "Without that, nobody flies."