Another tool is the basic aviation meteorology learned during training, which teaches that different cloud forms mean different kinds of weather. Cloud forms tell you a lot about airmass stability, convection, and turbulence. They herald the arrival of squall lines, cold fronts, and warm fronts, and are often the first visual clue to unexpected changes in weather.
Yet another tool that pilots acquire is training in emergency flight solely by reference to instruments. When all else fails, this tool may save the day during an escape from an inadvertent cloud penetration, or during a loss of visual reference to the ground above a solid cloud deck. If this element of training about clouds isn't accompanied by emphatic warnings about the dangers of non-instrument-rated pilots tangling with that kind of weather, it's missing its most important ingredient.
No way around it, clouds must be dealt with in visual flying. Get too close and you'll have problems. Stay too far away and you'll spend more time on the ground than necessary. Understanding the nature of the clouds you meet is necessary for a cloud-coping strategy to work. Just hazarding a guess whether to go over, under, or around the clouds that you find is what gets people in trouble. From the less-successful guessing come the harrowing stories of non-instrument-rated pilots attempting let-downs through thick, bumpy cumulus, or getting trapped above a low overcast or ground fog.
| Cumulous clouds (top) can go from fluffy and benign to dark and threatening on a summer's day. A high stratus overcast (middle) could herald the approach of a front, but the wispy stratus formation (above) on a nice day generally doesn't pose a problem for pilots. |
Don't go there. Fly clouds responsibly. Get an instrument rating when the time is right. That won't make every cloud you meet a new friend, but each will become less of an adversary.
In the meantime, the clouds you saw on your training flights were trying to teach you something. How much thought did you give them? Maybe they forced changes to altitudes, courses, or even destinations. Even if the clouds met expectations from your weather briefing, did they arrive on schedule, or did they show up earlier or later than forecast? Were you surprised by the clouds' physical appearance, or were you able to use other observations--wind direction, barometric pressure trends, weather reports from nearby stations, and so forth--to predict what you would find?
There are two ways in which a VFR pilot typically copes with clouds during a daylight flight. One is deciding on an altitude to fly so that you will avoid the clouds you meet. The other is deciding whether the appearance of clouds along your route suggests that continued visual flight won't be possible.
It's a whole different matter at night when avoidance isn't so easy. Reserve your night visual flying for the most predictable weather. Always have a clear-weather airport behind you as an out, and be sharp with your instrument skills.
Day or night, be super-alert to conditions that cause radiation fog to form, or cause advection fog to move in and hide your destination. Precipitation fog after a heavy rain is another possibility--it can materialize thickly and suddenly. Clouds that should trigger extreme wariness are unforecast clouds--why did they form? That's another way of asking what part of the weather picture has changed in a less-than-favorable way.
One of the most common VFR-and-clouds decisions that active pilots make is to depart on an early morning flight as soon as the previous night's radiation fog breaks up enough to allow escape from the ground. Flying in clear air above an endless carpet of billowy cotton, you observe more and more ground peeking through as the sun gets higher and warms the air, causing the moisture in it to re-evaporate. Fine, but it is a strategy fraught with assumptions. It could remain foggy along the coast or in a mountain valley long after everyone else is basking in sunshine. Consider probable conditions at your destination--don't make the mistake of assuming that things will be fine when you get there just because they are fine at your home airport. Even an airport liberated from morning fog could go back under if a slight breeze gets another body of fog moving. That could be quite a surprise on takeoff or if a quick return is required.
Here is another situation that any VFR pilot might encounter on any nice summer day. It's midmorning, and your mission is to fly a typically quipped Cessna 172 from your coastal home base to an airport 50 nautical miles away in the highlands. The forecast is standard summer fare: scattered clouds at 5,000 feet, visibility 20 miles, surface winds from the northwest at 10 to 15 knots. Later (when the sun goes down) the scattered clouds are forecast to disappear, wind diminishing to light and variable. Back at your home base there's a chance of fog this evening.
Your magnetic course to the destination is northeasterly. A cruise altitude of 3,500 feet, according to the hemispheric rule, seems like a good starting point--high enough to see your checkpoints and avoid obstacles; low enough to avoid prolonged time nose-up in a climb. The summer cumulus have started to sprout by the time you are airborne. They're dense enough to project dark shadows on the ground. The thermal currents that grow them make the air choppy. Soon your lightly loaded Skyhawk is rocking like a boat, and you aren't feeling happy. Time to change tactics?
A pilot report filed nearer to your destination gives the tops of the clouds as 6,000 feet msl, and the cloud cover remains scattered. Your choices, as you take your lumps in the bumps, are to tough it out, or climb above the convection--at least to 7,500 feet, where a smoother ride awaits. Tempting, but not without risks. Constant monitoring of cloud development will be required to ensure that 7,500 feet remains high enough for separation. Also, the sky cover could go from scattered to broken or overcast, threatening to trap you on top or bring you too close to clouds on the way down. There is also the return flight to consider; continued solar heating may mean more cloud development, perhaps even thunderstorms; the approach of sundown could help ease conditions. (Student pilots take note: Some instructors prohibit their students from climbing above a cloud layer--even a thinly scattered one. And the federal aviation regulations prohibit solo flight when "the flight cannot be made with visual reference to the surface.")
On another day a pilot is southwestbound toward a destination forecast to go under the foggy, rainy influence of an approaching warm front several hours after arrival. A high stratus overcast is already above as he makes his way along the route. Visibility is good, but not great. The pilot is surprised to look down from his cruise altitude and see shreds of stratus beneath; up ahead they seem more plentiful, and lower. And the visibility is deteriorating.
The destination is still many miles away. An update on its weather reveals a broken cloud deck at 2,000 feet, an overcast at 3,000 and multiple layers above that. A rain shower started a few minutes after the hour there and lasted for 20 minutes. This is worse than previous reports. What are the pilot's options?
Frontal weather is different from the example of cumulus buildups on a fair day. With the approaching warm front there is little doubt that visual meteorological conditions will soon fail. The front with its lowering ceiling and multiple layers is moving in more quickly than expected, meaning worse weather sooner. Staying above the clouds now could trap you between layers or cause you to blunder into instrument meteorological conditions. Descending into poor visibility over unfamiliar terrain, and tangling with that low stratus, would be equally inadvisable. If the destination weather is already going down, it will be worse at your estimated time of arrival. Turn around and go home or land at a nearby airport.
Don't get your first taste of such weather alone and in a state of surprise. A private pilot I flew with long ago says that one of the most educational flying sessions we shared started with a question he asked about the day's clouds. Heading inland on a cross-country, we opted to reverse course and fly toward the coast where a low stratus layer obscured the ground and where visibility was marginal so he could sample the conditions. It was fine on top of that weather, plus we had a sure escape to better conditions behind us, not to mention an aircraft equipped for instrument flight and an active instrument flight instructor aboard. This allowed the curious student pilot to experiment, confidently and safely, with flying in conditions that he would have feared solo. Absent the natural horizon or familiar landmarks that flying above this area normally brought into view, it was a new experience requiring attitude instrument flying and radio navigation. The point of doing it was not to embolden the pilot, but to answer questions and build knowledge. It wasn't a long session--but its value is summed up in the fact that a decade later, you're still reading about it, and he still talks about it.
What you teach another about patience and caution can be traced back to what you yourself learned. On a long-ago day, I was at the airport for an early-morning flight lesson. My mentor and instructor had arisen much earlier than I had and was already out flying. The airport sits along the river. A gentle breeze now stirred, carrying a large body of fog overhead and snuffing out the sun. This was followed shortly by the sound of a single-engine airplane overhead. His familiar voice came up on the common traffic advisory frequency, inquiring about the conditions.
The fog was low stuff, right in the treetops. Way too low to permit him to execute the necessary nonprecision instrument approach to get his Cessna 172RG back on the ground. But the layer was slowly lifting. Up in the sunshine, he circled patiently, chatting a little on the quiet frequency. Finally he said stand by, he'd give the instrument approach a try. After a little while, a landing light pierced the murk. He landed and taxied in. There had been no rush; no sense of indignation that, despite thousands of hours in the cockpit and promises scribbled on the flight schedule, some mere tendrils of moisture had imposed themselves on our big plans. Next thing we knew, the sun was out again.
Maybe it was weeks before we were teased by clouds again, or maybe it was later the same day--it's too long ago to remember. But clouds are like that. And they always teach you something, if the pilot wants learn.
Dan Namowitz is an aviation writer and flight instructor. A pilot since 1985 and an instructor since 1990, he resides in Maine.
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Links to additional resources about the topics discussed in this article are available at AOPA Flight Training Online.
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