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Wednesday, October 28, 2015

Weather pictures speak a thousand words, Part 2: Weather hazards

Part 1 had lots of pictures of air masses demonstrating how much the atmosphere flows like water. This time, let's see what happens when the weather misbehaves.


The problem with ice isn't, as many pilots think, that it adds a lot of weight. In reality, it doesn't weigh all that much compared to the enormous performance penalty it creates by changing the shape and/or smoothness of the wing surface. After all, how efficient would your wing be if it were made from rock candy?

That nub on the windshield wiper is put there specifically to ice up. That way you can easily see if you're picking up ice, since it's right in your field of view--unlike the wings.


Some days, you have no choice but to dodge towering cumulus clouds:

At least there was a gap between those. Here's something you don't want to see sitting right over your initial approach fix:

Sure, thunderstorms are pretty when you're sitting on the ground:

They're not so pretty when you're trying to get from one airport to another, however. This is a classic frontal line, where a cold front plows through, lifting the air ahead of it and creating a long line of thunderbumpers:

And this (like the first thunderstorm picture above) one is a classic air mass or "pop-up" thunderstorm. It's easy to identify because it's all by itself:

In What do beer and thunderstorms have in common? I wrote about what helps a pocket of convection build into a monster like this. If there isn't enough energy to create something like the big guy above, you might end up with a failed thunderstorm that never happened, like this:

You can tell from the wispiness of the cloud that it tried to get going but fizzled out. (Not surprisingly, as I took that picture at 7:12 a.m. before the heat of the day added enough fuel to the atmospheric fire. There were thunderstorms there later that afternoon.) However, if there is enough energy to get the convection ball rolling, you end up with something like the next four pictures, each taken two minutes apart:

See how fast that grew? In less than eight minutes, it went from a little puff to a decently-growing towering cumulus. If I'd have had a chance to take more, you probably would have seen it keep growing even more. It's almost like a bomb going off, which is what this pocket of convection looked like:

That's why in the post Why there is no reason to fly through a thunderstorm in peacetime I compared the average thunderstorm's power and an atomic bomb's power.

Ever wonder what rain would look like if you could see it from the side instead of having it fall directly on your head? On the ground, you can't do that, but from the air you see it all the time. It's the misty stuff in these pictures:

And here you can see some virga, which is rain that evaporates before making it to the ground:

Here I am getting rained on while above the clouds! Why? Because there's another layer above me:

But as the day goes on and the sun begins to set, the ground begins to cool and more energy isn't being fed into the convection system anymore. Things begin to calm down and die out:

Even when it's cruddy on the ground, it can be beautiful above. Check out next week's post for how pretty it can be once you blast through the gray on the ground.

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The author is an airline pilot, flight instructor, and adjunct college professor teaching aviation ground schools. He holds an ATP certificate with a DHC-8 type rating, as well as CFI, CFII, MEI, AGI, and IGI certificates, and is a Master-level participant in the FAA's WINGS program and a former FAASafety Team representative. He is on Facebook as Larry the Flying Guy, has a Larry the Flying Guy YouTube channel, and is on Twitter as @Lairspeed.

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Weather pictures speak a thousand words, Part 1: The air flowing like water

During the private pilot ground school I teach at the local college, we spend two full weeks on weather. Some people's eyes glaze over at the technical discussion of things like heat exchange processes, fronts, air masses, standard pseudoadiabatic lapse rates, and the other things that go into the atmospheric dynamo that creates the weather.

Personally, I love weather, which will probably come as no surprise to those of you who have seen all of the posts I've written on it throughout the last several years. One of the things that I enjoy most about flying is that you're not just talking about some abstract concept: you're actually up in the atmosphere dealing with weather on every single flight. That, after all, is why we spend so much time on it in class!

This time, instead of the typical post analyzing a certain weather phenomenon, I'm just going to show pictures of the processes in action. Lots and lots of pretty pictures. In fact, so many pictures I need to split this one into more than one post!

Air Masses

Weather comes from air moving. It's that simple. Everything else is details. The air starts moving because the equator heats up more than the poles because the sun hits the equator more directly. After that, the warm air tries to flow toward the colder poles. It doesn't make it there due to things like the coriolis effect, but its attempt it what sets the weather process in motion.

I said the air tries to flow from the equator to the poles. That's because one of the other important things to keep in mind is that air behaves like a liquid.

Yes, this is a picture of actual water. However, you'll notice that you'll see the same sort of behavior in many of the pictures to come.

Imagine dropping a pebble into a very gently flowing stream. It's easy to visualize what would happen: you would get ripples that would follow the current.

Now imagine that instead of dropping a pebble downward, you threw it up into the sky. That wouldn't do much, but if you heat a parcel of air (like, for example, by having a big smokestack with a lot of hot air rising out of it), you can do almost the same thing, as you can see in the next two pictures.

Now imagine if you had the same stream, but on the stream bed were some ridges. As the stream flows along, the water at the bottom gets pushed upward when it hits the ridges. This would cause some small waves or bulges on the surface. In Life on the Mississippi, Mark Twain recounts how he learned the art of reading the Mississippi River. One of the things an experienced riverboat pilot could do was to be able to read what's under the surface just by seeing what the surface looked like.

Air does the same thing and has the same telltale signs. I spend much of my flying time going across and along the Blue Ridge Mountains. I have numerous pictures of "gravity waves", which is the technical term for ripples in the air that happen when air hits something like the ridges of the Blue Ridge.

First, here's what the mountains themselves look like:

Now here's what happens when air flows across those ridges:

If the cloud remains connected between waves, the gravity wave "humps" are still there on top:

Here's an excellent cap cloud:

If the conditions are just right, the waves can actually crest! These are Kelvin-Helmholz waves, and can be seen where two fluids meet at different velocities. They can even be seen clearly and beautifully in the atmospheric bands of Jupiter, but on Earth they're easy to spot along muddy riverbanks where the slower water near the bank encounters the faster current in mid-river, or when a breeze blows over the ocean, or (like what's happening in this picture) a faster layer of air rides over a slower one:

Continuing with the stream metaphor: what would happen if the stream hit an obstacle that it was too shallow to go over? It would back up and be dammed, right? Or if you live near water, you've probably seen a breakwall, which is a man-made obstacle placed in front of waves to cut down on erosion.

If the conditions are right (meaning stable air and lots of moisture in that air), the air will do the same thing water would do: it will hit the obstacle and either try to crash over it or get backed up behind it. The next picture is what happens when it flows over it. Recall that as the air rises, it cools. Once it cools to its dewpoint, it dumps its moisture and creates a nice cloud that traces the ridgeline almost perfectly:

The next picture was taken outside the airport entrance at State College, PA, early in the morning. I was standing there for about 20 minutes watching the veeeeerrrrrryyyy slooooowww process of the air hitting the mountain like water hitting a breakwall and slowly splashing up and over it. And by "slowly" I mean about half an hour for one "wave"!

The next two pictures show the same thing happening a couple of months later:

Here is the air getting dammed when it hits the ridge. The sharply defined line is it stopping when it hits the ridge and getting backed up like water in a reservoir. If you look closely you can see the mountains it is hitting:

To cap off part 1, here's some very stable air trapping a cloud in between two ridges, with the skyline of New York City in the distance:

In part 2, there are more pretty pictures. This time, it's about weather hazards: icing and thunderstorms. If you've ever wondered what rain looks like from above, head over there now!

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The author is an airline pilot, flight instructor, and adjunct college professor teaching aviation ground schools. He holds an ATP certificate with a DHC-8 type rating, as well as CFI, CFII, MEI, AGI, and IGI certificates, and is a Master-level participant in the FAA's WINGS program and a former FAASafety Team representative. He is on Facebook as Larry the Flying Guy, has a Larry the Flying Guy YouTube channel, and is on Twitter as @Lairspeed.

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Wednesday, October 21, 2015

Why are some pilots more likely to declare an emergency than others?

Not long ago, I got into a debate over at the Flying Friends Facebook group on when one should declare an emergency. This just happened to be a couple of days before the sick passenger emergency in the last post. The original post was on a vacuum failure in IMC. I said I would declare an emergency. Many others said they wouldn't. One poster even ridiculed another who said he would.

My position was seconded by a retired 30,000+ hour airline pilot and given another nod by a current 10,000+ hour airline pilot. So my small-by-comparison 3,000+ hours were vindicated. However, as the discussion lengthened, a couple of things really stuck out at me:

1. The lower the number of hours, the less likely one would be to declare an emergency. This is exactly the opposite of what one would expect. After all, it's just logical that the more experienced pilots would consider fewer things emergencies. We get hammered in simulator sessions every six months with serious emergencies, so we have practiced things repeatedly that every pilot hopes they will never see. We have had more than a taste of things gone wrong. One would think that after those experiences, we would shake off something "minor" like a bad attitude indicator.

2. Everyone who was a professional pilot agreed with me. Some general aviation pilots agreed, but everyone who disagreed was a general aviation pilot.

These trends really surprised me. I've spent a lot of time thinking about them and trying to understand where they came from. These trends, I think, reveal a clear distinction between the mindset of the professional versus those who fly by choice rather than check. Here are three sources for that different mindset that I think are likely.


I know there is, in some segment of the GA community, a disdain for airline pilots. We are looked down on by this set as mere "bus drivers". However, bus drivers drive thousands and thousands of miles a year on all sorts of roads no matter whether it's snowing or raining or any of a myriad of other sub-par conditions that keep Joe Driver's sports car in the garage. By the same token, we flying "bus drivers" fly in conditions from 36-knot crosswinds to dodging summertime air mass thunderstorms to shooting an ILS approach to a snow-covered runway where the visibility is 1/2 mile because the snow is still coming down. While Joe Pilot (who thinks airline pilots have it so easy) is sitting at his computer reading Air Fact's "Go or No Go" column and saying "No Go" to marginal VFR, we're in the air flying in the soup.

In other words, we've seen a lot. One commenter disagreed extremely harshly with me that a vacuum failure in IMC was an emergency. Ironically, I have more time just in actual instrument conditions alone than all of the hours he has in his logbook put together!

The last two paragraphs are not meant to puff myself up. Mark Twain is often erroneously given credit for saying, "When I was a boy of 14, my father was so ignorant I could hardly stand to have the old man around. But when I got to be 21, I was astonished at how much the old man had learned in seven years." When I had 300 hours, I was a hotshot CFI who knew it all. Now that I have 3000 hours, I know I don't know it all. However, those paragraphs are driving at this point:

With experience comes not just the skill required to meet danger if it arrives, but the ability to recognize it when has arrived.

In other words, the old adage (which Wikiquote attributes to the astronaut Frank Borman, although he was almost definitely just passing it down, as it has been around a lot longer than 2008) that "A superior pilot uses his superior judgment to avoid situations which require the use of his superior skill." When you combine that with the other old saw, "Good judgment comes from experience. Experience comes from bad judgment," you get the sentence above.

So some of the reluctance to declare an emergency in this situation may simply be due to not having enough experience to recognize the danger that a dead vacuum pump poses to the safe outcome of a flight. Why get others involved over something as "trivial" as that? After all, isn't that why we practice partial panel flying as part of getting an instrument rating in the first place?

Anything that puts the safe outcome of a flight in doubt can be considered an emergency. Personally, I've spent enough hours slogging along in the soup that I know how quickly things can change and how insidious vertigo can be. That's why I would say right away that if my attitude indicator flopped over, I'd be declaring an emergency immediately.


Pilots are, in general, "can do" people. After all, just to get a private pilot certificate requires studying for and passing a written exam, the discipline to stick with 40+ hours of flying lessons even through the inevitable ups and downs, more studying for an oral exam, and all the time spent polishing everything up for the flight portion of the checkride.

The process tends to weed out those without the determination to set a goal and follow it all the way through to completion. That's why being in the top 2% of IQ qualifies you as a "genius" and gets you into Mensa, but successfully attaining a pilot certificate is something that less than .2% of the population has ever done. If you look it one way, it's 10x harder to become a pilot than it is to become a genius! (Yes, I am being facetious here.)

That determination and self-reliance is a good thing in most life situations, but it can also lead to pilots being unable to admit when they need help. They think that they should be able to handle anything on their own, so they are unwilling to declare an emergency in situations where they probably should.

Asking for help and/or declaring an emergency is not a sign of weakness. Being stubborn is not a sign of strength: it is a sign of weakness disguised as strength. There is no room in the cockpit for weakness at a critical moment, so check your ego and your stubbornness and if you need help, ask for it.


I've saved what I believe to be the most likely for the biggest number of pilots for last. There are probably many pilots who are reluctant to declare an emergency simply because they're reluctant to talk to ATC at all. They may realize something really bad is going on, and they may be humble wise enough to consider declaring an emergency, but they're too intimidated by the process of talking to someone "in control", or they may be unfamiliar with all the resources available to them if they'll just ask.

It may seem totally unbelievable that someone would be too afraid to ask for help, but I've seen the fear of "the system" in too many pilots to think it won't happen. I once gave a flight review to someone who had been flying for over two decades. As part of it, I asked him to plan a cross-country flight to a particular airport. He did a good job planning it, except he had planned a detour that added several dozen miles to the flight just so he could avoid transiting some Class B airspace along the way. And this is just one story of many like that.

It may be reluctance or it may simply be a general unawareness of what help a pilot can get by declaring an emergency; in either case, the outcome is the same: when you need help, it's not there, but it's waiting for you!

One of the reasons that I think that this is a big reason why airline pilots don't have a problem declaring an emergency when necessary whereas many GA pilots do is that airline pilots spend all day, every day working in the system. We talk to controllers hundreds of times a day. We're in the system so much we often have the next frequency tuned into the standby slot 30 miles before we're even switched over because we have them memorized. In fact, I know of more than one airline pilot who is in the system so much that they file IFR even if it's "clear and a million" because they're afraid to fly without ATC now!

This day-in, day-out familiarity with the system makes it second nature to us to declare an emergency if we need to. We know that controllers are humans, and we know they're an important member of the team. We know that like any good team-mate, they'll help us out if we need them to. In fact, in response to one commenter who said partial panel was no big deal, it was the 30,000 hour guy who said, "I'm glad that you're such a good pilot, but I need all the help I can get!"

Does this mean you should declare emergencies for everything? Of course not. In my 700 flights at the airline, we've only declared two emergencies. That means 99.72% of the time we don't (and there have been plenty of non-emergency things that have gone wrong on the other 698). In my 1900 flights total, I've only had three emergencies--one of which was a total engine failure. That means 99.95% of the time, I didn't declare anything. Here's hoping your rate is 100%, but if you need the help, don't let other people tell you that you shouldn't ask!


If you ever get into a situation where you do declare an emergency, here is a short list of the things you should do immediately:

1. Fly the airplane
2. Perform your memory items (you did memorize the bold printed items in your plane's POH, right?)
3. Fly the airplane
4. Run your checklist(s)
5. Fly the airplane

Remember: when you declare an emergency, it is still your airplane! ATC will do everything they can to help, but that doesn't mean they can fly the aircraft for you. It is still your responsibility to Get Things Done. Look at your emergency as a nail. If you ask, ATC can give you a hammer, but they can't use it for you: it's up to you to drive that nail in.

I'm going to get more into the responsibility that comes with being a pilot in the next post. See you next Wednesday!

Wednesday, October 14, 2015

What is an emergency?

In the previous post, I told the story of a recent emergency we had on a flight. It was easy to declare an emergency in this case because there was a big red warning light flashing on the glareshield saying that we may be on fire. However, most incidents that may occur in flight are not that cut and dried. So what exactly constitutes an emergency?

There is a saying in aviation that goes, "Some pilots will declare an emergency because of a failed magneto check. Others, upon having a wing fall off in flight, will merely request a lower altitude." This is one way of saying that there is no exact way to determine what constitutes an emergency.

The truth of this was borne out the first time we declared an emergency. Yes, the first time. The one I wrote about last post wasn't the first time I'd been in the cockpit when an emergency was declared. However, the first time was much more toward the first end ("mag check") of the spectrum.

The first time, we were heading to Charleston, WV. We were about 10 minutes out when the flight attendant called us to say that there was a passenger who was very pale and was having trouble breathing. We asked her to give the passenger oxygen and report back in five minutes. We had already started our descent, and in that part of the country there was no nearer airport, so we were definitely going to continue to the destination. We were also the only airplane in the entire airspace, so priority was not going to be a problem.

I called our operations staff for the normal "in range" call, which is something we do 10-20 minutes out to let them know we're getting close so they can start getting prepared for our arrival. If we have any special needs when we get there, like a passenger who will need a wheelchair, an unaccompanied minor, etc., we let them know as part of the call. This time, I told them we'd need an ambulance to meet the plane and briefly explained why.

Since "Charlie West" isn't a very big airport, the taxi time after landing is short, so we'd be at the gate in no time. For these reasons, I personally wouldn't declare an emergency. Everything would already be waiting for us and there is no other air traffic we'd need priority over. All we need to do is concentrate on the flight and land.

However, the Captain did declare an emergency. Is this the wrong decision? Not at all. Would not declaring be the wrong decision? No. I look at it as overkill, but no harm done except for a bunch of extra paperwork. The outcome would have been the same in either case under these particular circumstances.

(In case you're curious, I don't know what caused the passenger's problem. Once we landed and got to the gate, he was taken out of the airplane on a stretcher to the ambulance that was there waiting for him. However, he was up and walking under his own power within about 15 minutes of receiving treatment from the paramedics.)

What if we were in the same circumstances but going to Newark instead of Charleston? In that case, I wouldn't hesitate to declare an emergency. Why?

Because in Newark, there are a ton of other planes flying around, and sequencing all of us into the 20-mile conga line that New York Approach's controller/magicians keep churning along would take several extra precious minutes. In addition, once on the ground, the taxi time can be substantial. Declaring an emergency in this case could be the difference between life and death, as it would cut many, many minutes off the time to the gate. In this case, not declaring an emergency would be foolish.

One of our other pilots was in this scenario once, and on landing tower cleared them straight to the gate. This may not sound like much if you're used to a smaller airport where the taxi time is relatively short and you go directly from tower to ground and you're at the ramp in no time. In big airports, there's also a ramp frequency you use near the gate, which adds even more time. You also may have to give way to one or more other planes on the way in, since at Newark it's not usual to have at least a couple dozen airplanes moving on the taxiways at the same time. Being cleared straight to the gate means everyone else is getting pushed out of your way, and is a big deal when making your way around an airport as complex as this:

Even by large airport standards, Newark is a maze.

So not only is it sometimes hard to tell whether something may not be enough to be elevated to "emergency" status, sometimes the same thing definitely IS an emergency and under other circumstances may simply be an urgent condition.

In short:

Q: What is an emergency?
A: Anything that you believe reduces the certainty of the safe outcome of your flight.

Note the words "anything" and "you believe". When you're the pilot, an emergency is what you say it is. Not everyone will agree, but you're the one whose posterior is up in the air, not firmly attached to a chair on the ground.

This may be more useful to you than the FAA's definition in the generally-excellent Pilot's Handbook of Aeronautical Knowledge, which unhelpfully just says that an emergency is "a distress or urgent condition." (Thanks for nothing, PHAK!) However, that's not all there is to the answer.

In the next post, I'll go into some of the psychology involved in making the emergency declaration decision and examine a surprising difference between what GA pilots and airline pilots consider an emergency.

See you next Wednesday!

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The author is an airline pilot, flight instructor, and adjunct college professor teaching aviation ground schools. He holds an ATP certificate with a DHC-8 type rating, as well as CFI, CFII, MEI, AGI, and IGI certificates, and is a Master-level participant in the FAA's WINGS program and a former FAASafety Team representative. He is on Facebook as Larry the Flying Guy, has a Larry the Flying Guy YouTube channel, and is on Twitter as @Lairspeed.

It takes hours of work to bring each Keyboard & Rudder post to you. If you've found it useful, please consider making an easy one-time or recurring donation via PayPal in any amount you choose.