F-16 Fighting Falcon News

February 13, 2008 (by Scott Schonauer) - For years that has been the case at Spangdahlem AFB, where pilots have had to cope with a potentially dangerous and well-known optical illusion when approaching the runway.
The approach has long been considered risky, but the Air Force has made changes to the airfield to reduce the illusion in hopes of improving safety. Last year, crews added a dark epoxy coating to the ends of the runway and shifted antennas about 10 meters. The changes cost more than $1 million and were finished up last October. The base also completed a $3 million resurfacing job last year.

The illusion stems from the runway's incline. When approaching the base from the southwest end, the runway has an upslope that makes pilots erroneously believe the aircraft is coming in too high. The natural response is to reduce altitude to compensate for the illusion. The exact opposite phenomena occurs when a pilot approaches a runway that slopes down.

It is the first time the Air Force has made such changes to one of its runways, and engineers had to get special permission to add the coating, said Lt. Col. Kathryn Kolbe, 52nd Civil Engineering Squadron commander. But a unique solution was needed for a unique flight hazard, officials said.

The 52nd Fighter Wing made the alterations after an investigation into an F-16 crash on Sept. 14, 2006, found that the "visual illusion," in addition to the previous location of the antennae, contributed to the accident.

There have been at least seven incidents since the mid-1970s in which Air Force planes have either hit short of the runway or hit an antenna at the end of the runway, said Lt. Col. Tony Forkner, 52nd Fighter Wing chief of safety. The weather and the fact that the runway appears to be on a plateau because it is surrounded by valleys only add to the potential dangers.

"The runway environment here is a very challenging one," said Lt. Col. Scott Bowen, a pilot and the 52nd Operations Group deputy commander.

A report into the 2006 crash determined that then-1st Lt. Trevor Merritt of the 22nd Fighter Squadron might have been tricked by the illusion. He approached too low, clipping the far field antennae. That damaged his landing gear, forcing him to ditch the airplane near the town of Oberkail. He ejected safely from the fighter.

Pilots flying in and out of Spangdahlem have been warned for years about the illusion in their preflight reports.

By painting the ends of the runway a different color than the gray concrete, pilots will be able to see the correct touchdown point better, Bowen said. Moving the antennas also will create a buffer so pilots who come in low will have a lesser chance of clipping the antennas. Officials hope the changes will help save lives.

"We've only improved the airfield," Bowen said. "We've only taken away a significant number of those flight hazards. While I can’t promise that that is what’s going to happen, that was the intent behind all of it."