NTSB releases Stafford, VA preliminary accident report

It took awhile, but the preliminary accident report for a recent fatal crash at nearby Stafford, VA in February has been published by the NTSB. Accident reports like this one are important, not for the morbid details they sometimes provide, but rather for what can be learned from these unfortunate circumstances. While we'll never know what exactly happened, there are points of fact in these detailed reports that allow one to perceive the circumstances from a first person perspective to gain some insight.

The temperature dewpoint spread was reported as 5/3. The expected, theoretical vertical visibility would have been 900 feet, but the reported visibility was only 500. It seems likely from the weather described by witnesses that heavy banks of fog were in the vicinity of the airport. There is a phenomenon that occurs in such conditions where straight up and down visibility doesn't tell the complete story. While the horizontal visibility was reported at 1.25 miles, the presence of heavy fog can render visibility near zero at any time. Such are the limits of automated weather reporting without human intervention. At towered facilities, the weather information is analyzed and augmented by human observers.

So, as an aircraft approaches the airport and makes visual contact with the runway environment to continue for a landing, the visibility can go from acceptable to zero in fog (illuminated by the landing light and made worse) as the aircraft gets closer to the ground. If this occurs close to the ground and the runway cues (i.e., lights, centerline, etc) are lost, the plane is now in a no-man's-land situation past the missed approach point. The airplane is slow, the flaps are likely set full down, and the outcome has changed instantaneously from one of assured landing to a total "Uh oh!" to say the least.

Power, pitch, flaps, positive rate, climb, flaps. Forget any of those and the airplane will not fly too well. Put the airplane into a 30 degree bank as reported (to fly the published missed approach procedure), and it doesn't climb as well either. It will be interesting to see if the NTSB can determine if aircraft similar to the accident aircraft can climb with full flaps in a 30 degree left turn at high gross weights. It will be interesting not because that may have been the cause of the accident, but because no one may have thought to know the answer to such a question.