The runway at Pine Mountain Lake is oriented east-west, and is surrounded by rugged terrain. In poor weather, pilots are permitted to execute instrument approaches to the airport. The approach procedures guide pilots as they descend through the clouds to the runway. The procedures, flown properly, will place the pilot in a position to land straight ahead without having to maneuver. When the pilot pops out of the clouds after flying the instrument approach to Pine Mountain Lake, his view out of the windshield should be something like this:
The procedure the pilot must follow when approaching from the east is set forth below. A pilot may descend in the clouds no lower than 770 feet above the runway. To descend further, the pilot must
be clear of the clouds and have the runway in sight. If he cannot see the runway, he must "go missed." That means he must abort the landing, and climb straight ahead by reference to his instruments until reaching a safe altitude.
Once the pilot has reached a safe altitude and has established radio contact with air traffic control, the pilot may attempt the approach procedure again. He may obtain a clearance to fly a different approach procedure from the opposite direction, or he may opt to fly to a different airport where the weather is better.
Investigators report that the accident aircraft, N4175A, "went missed" on his first approach to the airport, and that the accident occurred near the completion of its second approach. On the second approach, the aircraft had successfully descended beneath the clouds. We know that because a witness on the ground saw the aircraft maneuvering. The witness saw the aircraft suddenly burst into fire, and then saw the aircraft crash. Investigators say that the aircraft exploded in flight because it hit a tree while maneuvering, and the tree ruptured a fuel tank.
The question is not why the aircraft hit a tree. Rather, the question is why the aircraft was maneuvering at all. The approach should have lined up the pilot for landing straight ahead. No turns should have been necessary.
It is true that pilots are permitted, once the runway appears before them, to circle around to land in the other direction if the surface winds require it. But this accident occurred after dark. "Circling to land" in poor weather at night is a challenging undertaking. There is a risk of losing sight of the runway, becoming disoriented in the dark, inadvertently re-entering clouds, or hitting obstacles that are hard to see. That’s why the "night circling approach to minimums" is considered the most dangerous of all instrument approaches. Most pilots will not attempt a circling approach at night unless there is no other option. Here, there was an option. If the winds required landing in the other direction, the pilot could simply have flown the other available approach procedure which brings the aircraft straight in to the runway from the west.
The NTSB will now take over the accident investigation. It will be difficult. Air traffic control tapes are often useful in reconstructing accidents such as this one. But there is no control tower at Pine Mountain Lake, and so the pilot would not have been communicating with any air traffic control facility in the final stages of the flight.
The NTSB will also be interested in the weather conditions that the pilot encountered. In particular, it will try to determine the altitude of the cloud bases, the direction and strength of the surface winds, and how far the visibility was. But there isn’t any weather recording equipment at Pine Mountain Lake, either. The closest equipment is 15 miles away, at Columbia Airport.
Photograph of the accident aircraft, Piper Saratoga N4175A, departing Oshkosh last summer.
Update: NTSB Releases Prelimary Report