Weather wolves

November 1, 1995

The biggest challenge facing general aviation pilots is the weather. It doesn't fit into neat compartments. You can't memorize it like takeoff and landing speeds. Most pilots eventually learn their aircraft, but weather doesn't come with an operating handbook. It comes, instead, with dozens of textbooks, weather maps, lapse rates, instability indexes, satellite images, prog charts, and forecasts. It is a study of possibilities and occasionally probabilities. The wolf is out there. Our challenge is to figure out where and when.

A few items jump out of the accident records. Over the last several years, the AOPA Air Safety Foundation's annual reviews of accidents show that the leading cause of serious accidents in high-performance single-engine aircraft and twins is weather.

Another item: There are almost no weather-related accidents during instruction. This is good — pilots and instructors are making good decisions, perhaps. It also reflects that most general aviation pilots get very little training in weather. In many cases the instructors have considerable experience in the local area and in preparing students for checkrides. Many CFIs typically don't have much experience in the weather on extended trips and in dealing with the meteorological quirks that befall the unwary in each part of the country. This is where the problem begins.

Most CFIs choose the weather carefully for dual cross-countries. After all, you need to see the countryside well to perform pilotage. This is good for beginning students; but, in the interest of getting through the process as quickly as possible, we typically give only the most basic cross-country prep. It's expensive flying all those hours from A to B. Unfortunately, it does very little to prepare pilots for the big and sometimes not-so-friendly skies that may appear following the checkride.

In the foundation's safety reviews on high-performance aircraft, the leading cause of serious accidents is poor weather judgment, not system mishandling. The Piper Malibu/Mirage, which is one of the most thoroughly researched aircraft in recent history, is a complex machine and eminently worthy of thorough training. But guess what? System problems did not bring down many of the aircraft — weather entanglements did. The NTSB made a big fuss about pilots' failure to turn on pitot heat in the Malibu; but in four out of five accidents involving suspected pitot icing, the flight was operating in or near thunderstorms, with a subsequent loss of control in heavy turbulence. Airplanes generally do not fall from the sky because the pitot tube ices up (with one well-known exception of a Boeing 727 in which the crew became disoriented).

Weather flying is a skill that must be learned and is not taught in many flight schools. You can't learn weather from a book, a magazine, or a videotape — or even by attending one of the Air Safety Foundation's seminars. As any knowledgeable pilot will admit, weather has so many variables that it must be learned in the cockpit. You can learn some theory and begin to understand some of the basic workings from the other sources, but it is only after flying cross-country for some time that pilots begin to develop real weather judgment.

Past experience must be applied with caution. What looks like a similar condition for a particular flight may not be. Being curious (or, more accurate, suspicious) about the weather is the key to safety in some conditions. In the words of "The Gambler," you gotta know when to hold 'em and when to fold 'em.

One of the major changes in the weather equation is how pilots get weather information. Flight service is the starting place for many pilots. Flight service has changed from the small stations that, decades ago, were located all over the country and typically staffed with pilots and other weather-savvy folks. Today, large automated facilities are populated with civil servants, some of whom are incapable of interpreting weather for a pilot. In many cases they are reluctant to go beyond reading the forecasts. If the forecast is in error and conditions are changing, many briefers will not extrapolate or make an educated guess until a new forecast is issued. Occasionally you can find a briefer who will go out on a limb to provide some sage advice, but often a question will be answered with a rereading of the warnings.

I have heard of several new pilots who were dissuaded from taking VFR trips where the departure and destination were superb but there was some early morning ground fog at several reporting stations along the route. This prompted a "VFR not recommended" warning. Never mind that the fog was a local condition, that it would burn off within a few hours, and that it would have no impact on flights not operating out of those airports.

You cannot blame the government for being overcautious. At any given time they are defendants in lawsuits in which families are looking to recover damages because of a perceived failure to warn. That is a topic for another time. The reality is that we have a system prone to crying wolf even when the wolves are several counties away. It is much more difficult to collect damages if a warning was provided even if the threat was not there.

For example, in July, I had a one-hour trip in a Cessna 172 from Lock Haven, Pennsylvania, down to the Baltimore area. There was a stagnant high pressure area that had dominated the region for a week with soaring temperatures and ozone counts. In-flight visibility was about four to five miles in milky haze. I was quite certain that the weather had not changed much in the last several hours, but one should always be cautious in an area where thunderstorms may develop.

The forecast had called for scattered storms after 9 p.m., but we expected to be at the destination by 7 p.m. My call to flight service was a disappointment in weather dissemination. I was warned about rapidly developing thunderstorm areas, which was a bit of a surprise since the sun was shining and there were literally no clouds in sight. I concede that the weather folks usually operate in opaque buildings, which does not help "now casting" much.

The only way to deal with this kind of weather briefing is to start asking very specific questions. Where are the thunderstorms now? Where are they moving? How big is the area? Are the storms increasing or decreasing in intensity? Do you have any pilot reports? After multiple questions we were able to ascertain that this particular area of storms was at least 75 miles to the east of my route. The briefer then brought up a line of developing storms in West Virginia. This was 100 miles west of my route; but to be sure, we played "Twenty Questions" again until I felt comfortable that nothing was in the cards for the next few hours. The flight was uneventful; and, sure enough, around 10 p.m. the line went through with a vengeance. Timing is everything.

The problem with FSS pseudo-wolves is that periodically there is a real one out there. The neophyte weather pilot does not know enough to recognize that this time IFR conditions means "It's For Real." The accident reports are replete with examples of incredible ignorance and, in some cases, downright stupidity, involving pilots who do not know when to fold their cards and stay on the ground.

The solution? I don't think there's a quick one, since this has been general aviation's most vexing problem — but it's not hopeless. The first suggestion is to start developing an interest in the weather. Read the magazines and books. Watch the videotapes. Watch the TV forecasts and plan hypothetical flights. With Duats you can get a very thorough briefing on existing weather and forecasts. If it is marginal, go back and look at the actual sequence reports a few hours later to see whether you called it right. This same process can be done with flight service.

Identify someone at your local airport who has done a lot of cross-country flying. Hitch a ride or invite the person to ride along with you and start developing that all-important windshield perspective.

The Air Safety Foundation has a safety review on weather-related accidents under way, so watch this space next spring. We'll show you where the problems are so that you can focus your efforts on avoiding the real weather wolves.


See also the index of "Safety Pilot" articles, organized by subject. Bruce Landsberg is executive director of the AOPA Air Safety Foundation.