Plows are working overtime again to keep flights coming in and out of South Bend Regional Airport. After all, a clear runway is the key to a safe take-off and landing.
But you may be surprised to hear how the airport tests runway stopping distances, one screech at a time.
Using a very tiny and expensive device called a friction declinometer, airport officials know how safe it is to land regardless if the incoming arrival is a turbo-prop Cessna or a Boeing 757.
"When the weather changes so does the friction,” Sean Flanagan said with the airport’s operations division.
Flanagan’s friends drive snow plows. However, he sits behind the wheel of a Ford F-250.
"A little kid would just love to come and drive around in a pick-up truck like this,” Flanagan added.
It's all to test 47 lane miles of runways and taxiways. So at 20 miles per hour, Flanagan slams on the break as the declinometer measures the vehicle’s stopping distance.
"This takes a reading of that and the reading we just got is a 24,” Flanagan said as he reviewed a recording.
To meet FAA requirements, Flanagan has to conduct nine checks, along each active runway, every two hours, during inclement weather.
"We’ve got a finite amount of runway. It’s about 8400 feet of runway here and planes need to be able to stop before the end,” Flanagan remarked.
Most planes land between 70 and 150 miles an hour, so it’s crucial that Flanagan’s vehicle stops on a dime, every time, before allowing aircraft to land.
"That scored us an 84, which is extraordinarily high. It’s about the best I’ve ever seen,” Flanagan said laughingly after stopping on a well plowed runway.
After running each round of tests, stats are sent to the control tower so the next flight knows what to expect, when its wheels touch down.
"For 35 plus years we haven't had to shut down the runway. So we stay open as other airports close,” Flanagan concluded.