Weather
© Hal Stoen
May, 2002 revised 2/9/2005

Revised: 2/23/2008: Minor spelling corrections.

Mea Culpa

Ah, no- I won't go down that road. This page is not an "all about aviation weather" page. I'm not a meteorologist, and there are already too many good sources on the subject already out there. No, this is more about practical usage of weather and aviation Gems that I picked up along the way, some insight, and some opinions that I have on the subject.

A short story

I was returning late one evening from the East Coast to our home base in Minneapolis. This was shortly after the company that I worked for had purchased their new Cessna 421B, N1557G, and before we had built a hangar at a Minneapolis satellite airport.

Five Seven Golf was berthed with the big boys at the corporate facility located at MSP.

On this flight I was the lone occupant of the aircraft, positioning back to MSP for another solo flight early the next morning to Wichita, Kansas. It was November, and a major snow storm was brewing in the Southwestern United States that would affect tomorrow's flight with severe restrictions to visibility and low ceilings over both my departure and arrival points. I learned all of this as I received my weather briefing while in the air grinding along Westbound. I called my wife on the aircraft's telephone telling her that I was going to spend the night at the crew quarters located in the FBO.

After wakening early the next morning, I called the MSP FSS to see how the snowstorm was doing. The weather was clear in MSP, enroute, and at my destination, ICT. What happened to the storm? Frontalalisis. A relatively rare situation where a storm literally falls apart. Just as the amended forecast said, I sailed off and arrived in severe clear.

Why do I tell this story?

Because weather is dynamic. I've read thousands of articles and books on aviation weather, and all of them use words like "sometimes", "usually", "in most cases" and so on. Why? Let me say it again. Weather is dynamic. The pilot that places blind faith in forecasts of decent enroute and landing weather at his destination is a pilot that will some day meet his fate at the hands of the Weather Gods.

This is not to fault the good folks at NOAA (National Oceanic and Atmospheric Administration), otherwise know as "the weather bureau." Nor is it a reflection of the aviation weather briefer that dispense information to pilots at the FSS (Flight Service Station). They do their best with the tools of their trade, and will tell you the same thing- it's really difficult to predict the weather accurately because it's so, you guessed it, dynamic. Back "in the old days" Flight Service Stations were scattered all over the United States, and your odds of talking to a Briefer face to face were pretty good.

Today, many of these facilities have been closed and consolidated. Minneapolis FSS is no longer at the MSP Airport, but is at a small airport many miles North of the Twin Cities because that small town won the "bidding war" for a new facility. Trust me, this was not done so that the FSS personnel could do their jobs better, or so the pilot could get a better briefing- like similar consolidations across the US it was all about money. If you are fortunate enough to live near a FSS please visit it. The briefers will love to talk to you face to face, and you'll walk away with a better understanding of what is available to you. And lastly, the FSS Briefers are technically not supposed to give their opinions- although the good ones will. If something doesn't smell right, ask the Briefer what he thinks. You might be surprised at his candor and the extra insight that you will receive.

So what's a pilot to do?

First of all, be a weather skeptic. Don't accept weather reports with blind faith. Whoa, wait a minute here. "Don't accept weather reports with blind faith?" How can this be? Am I saying that a simple hourly weather observation could be flawed? Yes, I am. How can this be? Ah, Grasshopper because not all weather observations are taken by real live people- people that know what they are doing, professionals. No, increasingly more and more weather observations are taken by machines- automated weather observation systems, AWOS, among others. And these machines don't have a clue about what's around them, just what's over them. Accept any observation from an "AWOS" station with great skepticism.

Secondly, get the trend of the weather. Get the hourly observations well before your scheduled arrival time at your destination, and check while you're enroute by radio. Compare these observations with the forecast. Is the trend in line with the forecast? Better? Worse? If your destination weather is headed South, every hair you have should be tingling an alert.

Thirdly, always have a "Plan B", preferably also a "Plan C." This not only applies to weather-related destination changes, but to airport operations also. What if an aircraft makes a gear-up landing shortly before your arrival and the airport is closed? Will you have enough fuel to get to another landing site? And for that matter, where is the next best landing site? Or, how about if that fog bank on the airport's perimeter- the one that a human weather observer would note, but a AWOS won't- moves across the field obscuring the airport? What if your destination airport is in excellent condition, but another one nearby has gone down to the nubs and the traffic that can no longer land there is alternating to your airport? You'll join the stack, and will have to hold just like everyone else. Got enough fuel for that?

PIREPS

That's aviation-speak for Pilot REPortS. Who else knows better about what's going on up there than you do? Share this information with your fellow airmen in the form of pilot reports. As you climb out, note the bases, tops, layers, icing, no icing, temperatures, turbulence and so on. Once established at your cruising altitude, use your equipment to get the actual winds aloft. Pass this on to the folks on the ground via the nearest FSS radio link. This applies to all phases of your trip- departure, enroute and arrival. They want to know, and they will appreciate your efforts.

Icing

A tough subject. Years ago, a Senior Editor for Flying Magazine wrote an article about flying in icing conditions. In effect, he wrote that reports of icing conditions should be taken with a jaundiced eye, and that one should have the attitude of going up and taking a look for oneself. It was a well thought out article by a very knowledgeable pilot. While the issue was still on the newsstands the author was killed in an airplane crash, brought about by severe airframe icing.

In another incident, years ago a United Airlines DC-3 encountered heavy icing at the Outer Marker on their approach to Chicago's O'Hare Airport. The Outer Marker! Less than six lousy miles from the end of the runway! When they staggered to a touchdown, the crew had full power on and could not arrest the descent. Ground personnel had to chip the ice off around the door in order to open it.

Wow. Such is the power of ice.

During the fall-winter-spring months, October thru May,Airmets about potential icing are issued virtually on a daily basis. This is almost more of a CYA than anything else. Icing conditions can be predicted, but the key is that the conditions are there- you may or may not actually encounter the stuff. As FSS Briefer Michael Gray (Lansing, Michigan FSS) said to me in an email "This trivializes the airmets because pilots receive them every time they fly, and then tend to discount them because most of the time they don't encounter significant icing."

Remember that anti-ice and de-ice equipment is there to help you get through or out of icing conditions, not for you to linger there. Turn on anti-ice equipment before you enter icing conditions. Use de-ice equipment judiciously and properly. (For an explanation of de-ice boots, and how they operate, see "Corporate Flight Ops." on the Stoenworks Aviation Page.)

Some years ago a major airline carrier cargo flight departed JFK without turning on the anti-ice equipment. As they climbed on instruments the pitot and static sources iced over. As the indicated airspeed increased due to this condition the crew added power and increased the angle of climb. The indicated airspeed continued to increase. When the aircraft entered a hammerhead stall the crew had full power applied along with an almost unimaginable deck angle. The hole that was created in the ground was hardly larger than the airplane.

When you encounter ice, do something. Go up, go down- it depends on the situation. For example, generally speaking (there's that caveat) if you encounter rime ice and turbulence at the same time, you're probably near the tops of cumulus clouds and going up will get you out of it. On the other hand, if you're near a warm front and know the surface conditions, a descent may be the proper call. Icing and how to handle it becomes, to a large degree, intuitive to the pilot after experience. Bottom line: respect the living hell out of airborne icing.

What about the other type of ice, the stuff that is on the airplane before departure? Well, depart with it and it will still be there when you crash. Frost on wings can and will keep an aircraft from flying. Clean it off before departure. Period.

Situational Awareness

I'm a big fan of this concept. Always be aware of how your aircraft is performing, and the status of its consumables- fuel, oil, oxygen and others. How do things look on the gauges that display the aircraft's overall health? Is that oil temperature gauge a needle width lower than it was an hour ago? More importantly, do you know what it read an hour ago? Is your fuel burn greater than you planned on? Is the air turbulent when it was forecast not to be? Are the winds aloft way different than what you were told they would be? These are indicators of a blown forecast. What's happening, and what are you going to do about it? Always be aware of the aircraft's status, where you are, and what the weather is doing- at your present location, and down the road at your destination and at your alternate.

Complacency can, and will, kill you.

Things just keep changing

In February of 2005 the FAA announced that they had awarded a contract to Lockheed Marting to provide (take over) the automated Flight Service Stations that are currently controlled by the FAA. (As of February, 2005 there were 58 of these automated stations in the continental United States.)

What does this mean to you the pilot? Well, first-hand observations of the weather that we fly in have not been improving, and although this change only concerns the automated station, I think that one can see the writing on the wall and that as non-government operations move in we will see a steady decline in actual "real person" aviation weather observations. It's a sign of the economic times, but also should alert you that as a pilot you need to get as much information, and as from as many different sources as possible, about the air you are about to fly in.

And Lastly

It has been said that "If we could see the air that we fly through, we wouldn't fly through it." Truer words were never spoken. And, quite frankly, many pilots have a tendency to give weather a short shrift. Don't be one of them.

It only increases your chances of becoming a statistic.

Fly safely.

This tutorial is available on a CD

This tutorial, along with additional content, is available on a CD. Click here for more information.

Hal Stoen

May, 2001

Additions to this page were made on 5/13/2002 after I received some insight from Michael Gray of the Lansing, Michigan FSS. Thank you Michael.

Revised: 2/23/2008: Spelling corrections made. Thanks to Alan Larson for pointing these out.

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