Your final approach has been perfect and now, as the threshold begins to slide beneath the nose, it looks like this is going to be one of your best night landings ever. As you savor the sight picture in the windscreen, it vanishes. Some glare from airport lighting remains, but that’s it. Shocked by the abrupt loss of references, you have applied some involuntary control pressures to the yoke—but you have no idea what they were. As your brain works to wrap itself around the idea of the only remedy for this predicament—a go-around flown by instrument references—the aircraft slams onto the ground. Six months later, after investigating, the National Transportation Safety Board updates its preliminary accident report with a probable cause: “The pilot’s failure to perform a go-around after encountering thick fog at night.”
Viewed from above as it forms on an early evening, fog can appear gauzy and thin, barely imposing a halo around surface lights. Viewed along its long axis, however, that same mass of fog can be no more transparent than a brick wall.
You probably have read about that fog hazard, especially dangerous when it forms on a cool, clear evening when restrictions to visibility were not a concern earlier in the day. If that brand of fog—known as radiation fog—develops quickly enough as the temperature drops to the dew point, its presence can come as a complete surprise when it presents itself at a critically low altitude.
If fog is notorious for its surprise factor, some mishaps demonstrate that awareness of its presence won’t protect a pilot who allows a sequence of events and pressures to form an accident chain.
On December 7, 2012, a noninstrument-rated pilot flying a Bellanca 7ECA crashed into a plowed field in Tehachapi, California, shortly before dusk after attempting to land at a fogged-in airport. Widespread fog had already been visible during the en-route portion of the flight, the NTSB said. “The pilot attempted to listen to the airport’s automated weather observation system but could only discern the altimeter reading due to radio static. He initiated a descent to the traffic pattern altitude and observed fog approaching the airport’s perimeter. The pilot further stated that as the airplane was on the final approach path, about three miles from the airport, the visibility began to decrease. In an effort to maintain visual contact with the airport, he maneuvered the airplane below a fog bank and elected to continue the approach in instrument meteorological conditions.”
The pilot lost all visual references at about 500 feet above terrain, after which the airplane hit the ground. The accident report also noted that at the time of the pilot’s initial weather briefing, the destination airport was already reporting instrument conditions.
The pilot had considered—but eventually discarded—a plan B: The report noted that “despite the possibility of fog at his destination, he decided to attempt the flight with the intention of diverting to an alternate airport if the weather conditions deteriorated.” Included in the NTSB’s determination of probable cause were the pilot’s lack of an instrument rating and the “loss of situational awareness arising from the continued descent into instrument conditions.”
It’s always a rewarding feeling to spot your destination and notify the air traffic controller who has been providing you with radar advisories that you have the field in sight. The last thing a pilot may expect at such a time is for the runway to suddenly vanish in a thick fog.
That, said the NTSB, may have been what happened when a commercial, instrument-rated pilot attempted to land at a lighted private airstrip in western Iowa on December 1, 2012. Two passengers perished, and the 70-year-old pilot died from burns and injuries two months later, according to newspaper accounts.
The 2,400-hour pilot, who was flying a Beech Bonanza P35, “advised an air traffic controller that he had the airport in sight, and the controller acknowledged and told the pilot that radar services were terminated. The airport had an unimproved grass strip and runway lights.”
The accident report incorporated weather observations from nearby: “Two witnesses who lived next to the airport said thick fog quickly enveloped the area shortly before the accident. Another witness said that visibility had dropped to less than one-quarter mile and that he heard the airplane fly low over his house but could not see it. On the approach to land, the airplane struck trees and terrain about one-quarter mile northeast of the airport.”
The NTSB attributed the accident to a failure to execute a go-around when encountering the thick fog. (A subsequent accident involving the ambulance transporting the pilot, and a police vehicle, also was attributed to the fog.)
On the subject of that go-around: During your next night approach, be sure you are ready to perform one on an instant’s notice—even with the runway now clearly in sight.
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