Why VFR into IMC?

Some accidents aren't. That is, they do not fit the definition of being unexpected or unforseen events.

The results of pilots flying VFR into instrument meteorological conditions, or VFR into IMC, really are no surprise. The most recent Nall Report, the Air Safety Foundation's annual review of accidents that is published each spring, noted that there were 33 accidents in 2001 where the NTSB reported pilots getting into clouds when they weren't on an IFR flight plan.

In a few cases there might be some extenuating circumstances resulting from unforecast weather. It's rare but it happens. In many more cases there were clear warning signs that the pilot overlooked out of ignorance or carelessness. In the majority of these crashes it appears that the pilots made the decision to launch, or continue, into weather that was clearly inappropriate for their skills or the flight rules under which they chose to operate.

An interview after the crash might unravel the thought process behind what has to be one of the highest-risk activities in aviation. Unfortunately, we don't get to talk with many of the pilots because very few survive the experience. Some possible answers: "I couldn't see the clouds into which I was flying because other clouds were obscuring my vision;" or, "The layers were pretty thin and I felt I could get on top (or underneath) before losing control;" or, "I've always been a little foggy about that temperature/dew point relationship;" or, "I've done this many times and never had a problem, until today." This last one might be the most popular.

There are two scenarios regarding the impacts: out of control, typically in a spiral or with the aircraft disassembling itself after the flight exceeds VNE; and in level flight and in control, right up to the sudden stop. An example of each is offered below when a pilot goes into IMC conditions. Although it is a very serious situation and some people may consider it sort of funny, we still can use it to learn Aviation English phraseology in a totally non-routine event. 

By Bruce Landsberg