Night Vision Dangers
By H. Dean Chamberlin
Article reprinted with permission of FAA Aviation News
If you don't survive your crash, it is pointless to discuss post-crash desert survival. To illustrate this point, Mr. Robert J. O'Haver, an FAA Aviation Safety Inspector assigned to the Flight Standards Service's General Aviation and Commercial Division's Operations and Safety Program Support Branch in Washington, DC, told the following story. Although he thinks the story may make him look foolish, it is a good reminder to those pilots who have never flown with 60 or more miles of nighttime visibility of the dangers that may be lurking in a clear, moonless desert night.
O'Haver, who has flown extensively throughout New Mexico, said pilots have to remember the lights they might see in the desert at night may be 60 to 80 miles away. He said long-range night visibility can be potentially hazardous for those not aware of the risks it poses.
To illustrate his point, he told the story about one of his flights in a Beechcraft
King Air on a dark, moonless night. 'I was flying about 10 or 11,000 feet IFR. I could see the lights of cars moving along a road across the desert. It was easy to start using the lights as the horizon. But after a while, I realized that the aircraft was turning. I kicked in some rudder to stop the turn when I realized that the problem was the road was now slanting across a mountain. I had been trying to use the sloping line of lights on the mountain as the level horizon.'
He told about a nighttime turbojet accident that happened when the crew flew into a blacked-out hill after they lost sight of the airport lights. Blacked-out areas are particularly dangerous in remote areas where there are few or no ground lights. A good rule of thumb when flying anywhere at night is that normally in built-up areas people build houses everywhere. A black hole or an area with no lights either means a mountain, hill, or body of water. There has to be some reason people didn't build in that area if the rest of the area is built-up and lighted. That reason could be dangerous to an aircraft.
'To avoid such problems,' he said, 'pilots need to review the
Aeronautical Information Manual's (AIM) section on visual effects to avoid a similar night-time accident when flying on moonless nights over the desert.'