Safety Publications/Articles


Barefoot IFR

Relying on knowledge, skill, and cunning

About eight years ago, I wrote an article (see "Never Again: ATC Reliance," August 1996 AOPA Pilot) that related one of my more harrowing experiences since learning to fly. I was on an IFR flight with my family in the middle of summer, and we tangled with some severe thunderstorms. I had mistakenly turned over my decision-making to ATC, believing that the controllers would always keep me out of trouble. I had learned to rely heavily on ATC for weather avoidance from my instructor, who employed it consistently during my IFR training.

This all occurred in 1981, before the new weather reporting devices were available in the cockpit. After getting trapped between storm cells with no place to go and pleading to ATC for help, the controller informed me that his radar didn't show weather and then asked if I was aware of the convective sigmet that had been issued. This was a surprise, since ATC told me along the way that they would get me around any bad stuff ahead. I learned later that the Chicago Center controller had his hands full sequencing and separating traffic because of the weather, and providing me vectoring was not a priority. Since I am still here to write this article, you can assume that I survived the incident, shaken and embarrassed, but determined to be more self-reliant and knowledgeable in the future about weather.

Advances in weather predicting and reporting have been phenomenal. Back then, high-tech at most flight service stations meant an hours-old faxed radar summary and hourly reports and forecasts, perhaps some pilot reports, but nothing real-time. Today, flight service stations (FSS) have weather radar; controllers have weather radar located near their positions; center and approach radars are more flexible in showing weather; and we are beginning to get real-time weather information from devices in the cockpit. Prices of in-cockpit equipment are beginning to drop, while the equipment gets better. For example, NavAirWx has developed a relatively inexpensive cockpit weather reporting system, which utilizes a satellite phone or XM satellite radio service that displays real-time weather information on a handheld personal digital assistant with an integrated GPS chip.

Having said this, new technology does not relieve the pilot from having a good, basic understanding of weather theory and how to prepare for and avoid the bad stuff without the aid of these sophisticated systems. What if you can't afford it, or you fly a minimally equipped rental, or the new device fails? You, the pilot, are the last line of defense against weather conditions that neither you nor the airplane are able to handle.

I know all of this makes me sound like an old curmudgeon who remembers the good old days and may even be skeptical of the invention of the telephone, but I have an honest concern that pilots will become so dependent on the new cockpit weather devices that they will not be well-grounded in basic weather knowledge. In my frequent instructional flights, I notice that many pilots, most well seasoned, do not possess a basic understanding of weather theory and have not reviewed it since they prepared for their private pilot exams. Some are daredevils who don't pay a lot of attention to the weather anyway. I try to rein in these characters. Others are overly conservative and won't fly if there is even the slightest chance of adverse weather. This comes from an insecurity and basic lack of knowledge about predicting weather. They don't fly much because most of the time the summer weather forecast calls for "a chance of thunderstorms." They don't fly much IFR in the winter because forecasts often call for "occasional icing in clouds and precipitation." If they knew something about how thunderstorms and icing form and how to avoid these conditions, they would get more use of their airplanes.

One needs to calculate the probability of encountering hazardous weather before it's encountered, not afterward. In this day of computer games, it's easy to turn over your thinking and responsibility to what is displayed on the screen instead of taking a comprehensive approach to why and how the weather is occurring. Encourage your students and others with whom you fly to attend safety seminars on weather and read the many good aviation weather books available. The AOPA Air Safety Foundation has just introduced a new full- length live seminar called "WeatherWise: Tactical Tricks and Practical Tips," and plans to introduce at least one new online weather course each year for the next four or five years. More information is available online.

Can you always rely on ATC to keep you away from the bad weather? First of all, remember it's not ATC's primary responsibility to do this. I've had several experiences since writing the "Never Again" article that make me even more cautious about counting on ATC for weather avoidance.

I was returning with a friend to the East Coast from EAA AirVenture in Oshkosh. The weather briefing called for the possibility of convective activity over Michigan. As we approached the eastern shore of Lake Michigan the view ahead was not encouraging. Using a Strikefinder, we asked ATC for headings that would get us through the heaviest of the weather. As we proceeded, we saw a bolt of lightning about one-half mile off the nose of the airplane. Surprisingly, the Strikefinder did not display any activity ahead. ATC by that time had become quite busy, and we had trouble contacting them. Flightwatch was also jammed with inquiries. It was lighter to the north, and we finally received permission for a deviation of about 90 degrees to get clear of the weather. As it turned out, we ended up in Canadian airspace before we were able to turn southwest and a heading for home. (Toronto Center refused to provide any assistance whatsoever with weather avoidance.) This is yet another case where personal weather judgment and knowledge trumps ATC.

For several days before departing Oshkosh, we had observed what the weather was doing. The Weather Channel and the surface weather imagery charts from Meteorlogix, available at AOPA Online, were both good sources for long-range weather planning, keeping in mind the limitations of long-range forecasts.

On the day of the flight, the humidity and dew point were elevated, the surface temperature was forecast to be in the 90s, and the Lifted Index (LI) was at minus 2.

GA pilots seldom use the LI, but it takes into account the availability of low-level moisture that is a good predictor of convective activity. If the LI is zero or above, thunderstorms are not likely. A LI of minus 1 to minus 4 is an indicator that convective activity is possible to extremely likely. Any lower number, say minus 5 to minus 6, indicates a certainty of strong thunderstorms and possibly tornados. The LI scale at minus 9 is labeled "Yikes." The LI is available from flight service, and LI plots can be found on various weather Web sites (just type "Lifted Index" in an Internet search engine).

When we departed Oshkosh we had all of the atmospheric elements necessary for convective activity and knew what to expect: high temperature, high humidity and dew point, lifting characteristics in the atmosphere, low LI, and an approaching cold front. Radar showed only a few isolated thunderstorms over Michigan, but we knew they were likely to become more numerous. We discussed Plans A, B, C, and even a D if we had weather problems, none of which relied heavily on ATC or the Strikefinder: (A) Fly the route as planned. (B) Turn back to Oshkosh. (C) Take a more northerly route where conditions were less favorable for development of weather. Or (D), land at the nearest airport if all else fails.

From day one, pilots should be taught to use every tool in the toolbox when flying. When it comes to weather there are abundant of resources available, the most valuable of which is one's own knowledge of weather theory and how to obtain good weather information. The new cockpit weather devices are miraculous and are enhancing safety. As time goes on they will become commonplace, more affordable, and more capable. But we must use them to complement our basic knowledge of weather theory, not replace it.

Richard Hiner retired from the AOPA Air Safety Foundation as vice president of training. He can be contacted at [email protected] .

By Richard Hiner

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