Monday, December 30, 2013

Airport for aliens?

I'm minding my own business, innocently wandering around a sectional chart, and I come across an oddly-shaped restricted area (R-4404) in Mississippi:

Excerpt from VFRmap.com
So I switch over to the satellite view of the area in Google Maps:

From Google Maps. Click image to embiggen.
I don't know what that V-shaped thing is, but it's obviously huge. So I zoom in a bit:
From Google Maps. Click image to embiggen.
Now the "X Files" music starts to play in my head, because I obviously have stumbled across a super-secret alien landing strip built for them by the military. It all fits: strange shape, remote area, protected airspace, the inexplicable popularity of Miley Cyrus... this explains it all! So I zoom all the way in, listening for black helicopters hovering outside my window, and find this:
From Google Maps. Click image to embiggen.
Turns out it's just a gigantic bull's eye that the Navy uses to teach their pilots the art of bombing. Looks like I'll have to go back to using chemtrails to explain the record sales of Miley Cyrus.

Saturday, December 28, 2013

How can two things be the same and different at the same time?

In the first part of this post, I explained why runway symbols change at 8069 feet. That post started innocently enough with this sectional chart excerpt:

Excerpt from VFRmap.com. Click image to embiggen.
I then pointed out that you can tell that the airport at the upper left has an 8000-foot runway because of the 80 in its data block, which is why it's in a circle:
So far, so good. However, if you looked closely at the airport at the bottom right, you may have noticed that its data block also says 80, meaning its longest runway is 8000 feet long, but it's not in a circle like it's supposed to be:

So why do these airports both have 8000-foot runways but different symbols? How can two things be the same and different at the same time?

That's because of the layout of the three runways. Since they're fanned out and so far apart, even though they're less than the 8069 round-up point, they still wouldn't fit inside the biggest circle chartmakers use. Therefore, they get drawn individually.

There's another example of this same thing in action. This time, it's at one of the most famous airports in all of general aviation. In fact, it's so famous, my coffee mug is sitting on it right now:
I obviously drink a lot of coffee.
That coaster is none other than Wittman Regional, better known as just "Oshkosh".
Sectional chart excerpt from SkyVector.com.
Oshkosh's runways are in a T shape, but there is a gap between the longer, 8000 foot north-south runway and the shorter east-west runway that makes it not fit in the biggest circle. If the runways intersected, making a + shape, for example, they would fit and it would be in a circle like a "normal" 8000 foot runway.

I won't go into the other exceptions that make second part of the Sectional Chart User's legend, "some multiple runways less than 8069'", necessary:

I will leave you with just one more, which is Evansville Regional Airport in Indiana, which is 8020. That saves the rest for you to tell me about in the comments, since I don't want to hog all the fun. If you find one that is less than 8000 feet, be especially sure to share those, too!

Also, I will leave you with this brainteaser: it is possible for an airport or airports with hard runways between 1500 and 8000 feet that would fit easily into a circle to not be put into one. These airports also do not meet the exception in this post. Why do some charts show almost all public, hard-surfaced airports on them without ever using a circle? Share your answer in the comments. The first one to get it right wins a pat on the back!

Thursday, December 26, 2013

Why do runway symbols change at 8,069 feet?

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A popular question during the oral portion of a checkride is why does one airport have a runway symbol that looks like a circle but another one has a symbol that looks like an actual runway and no circle?

Sectional excerpt from VFRmap.com. Click image to embiggen.
The one in the upper left is a runway in a circle, while the one at the bottom right has three runways. Why?

Well, this excerpt from the FAA's Aeronautical Chart User's Guide has this in the legend, as does the back of every paper sectional you've ever bought:

OK, that means the airport at the top has a runway of less than 8,069 feet. If we look closely at its data block, the 80 in the bottom right means its runway is 8,000 feet, which is indeed less than 8,069.


But you're still wondering why the crazy number 8,069 instead of something less random-seeming. Well, first you have to understand that the symbols are drawn to scale. That means the bigger the runway, the more of the symbol it is going to take up. For example, compare the symbol above to the little Topton airport from the bottom of the first excerpt:
See how its symbol is smaller and the runway takes up less of it? That's because the 32 at the bottom right means that it's only 3,200 feet long. Smaller runway, smaller symbol. Bigger runway, bigger symbol. That's what "drawn to scale" means, after all.

Now that you understand that, you're still wondering what's so magical about 8,069. And I'm only going to tease you just one tiny bit more with this excerpt from page 9 of the Chart User's Guide:

"Runway length is shown to the nearest 100’, using 70 as the division point; a runway 8070’ in length is charted as 81, while a runway 8069’ in length is charted as 80."

So that explains the 69: that's the last number before the chartmakers round up.

The only thing left to explain is the 80. For that, remember how I just explained that runways are drawn to scale? At 81, they get too big to fit inside the circle anymore. That means they just draw the runway itself instead of a circle.

Fortunately, you won't need to get into that much detail on a checkride. In fact, if you were to go into that much detail, you might end up teaching your examiner something they didn't know. All you need to remember is runways stop being circled when they're over 8,069 feet long.

EXCEPT... for what we'll get into in the second part of this post, which is titled "How can two things be the same and different at the same time?" Look for the answer to that question on Saturday! (Hint: if you looked closely at the first chart excerpt of this post, you may have noticed an unusual coincidence.)

Tuesday, December 24, 2013

Santa's Base of Operations

Everyone thinks Santa flies his reindeer out of the North Pole. That's a clever piece of misdirection to keep his real airport free of tourists. Here's where your presents actually fly out of:

Click image to embiggen.
Merry Christmas to you and yours from Keyboard & Rudder. To hear a unique Christmas message from a different place in a very different time, check out this Wikipedia entry.

Sunday, December 22, 2013

When things don't add up

A month ago, I wrote a post explaining how that 747 might have landed at the wrong airport. Instead of calling them stupid or incompetent or joining in the chorus of indignation, I simply showed that it was an easy mistake for a human to make. I've been flying long enough to know better than to say "that could never happen to me", so I just gave a calm analysis and my best guess as to how it did. A month later, after some more information has come out, it turns out my guess was pretty close.

This week's AOPA/Air Safety Institute quiz was on the LOC BC-B approach into Rogue Valley International (KMFR) in Medford, Oregon. To keep my skills up, after I take the quiz I usually load up X-Plane or Microsoft Flight Simulator X and fly the approach. They're interesting challenges, since they're obviously not going to select a run-of-the-mill one for a quiz. This week was par for the course: a DME arc over high terrain to a localizer back course with a steep descent to a circle-to-landing. This is one of those approaches that leaves you feeling mentally drained after touchdown, even when you're just practicing from the comfort of home. That's why I enjoy flying them so much: they're excellent practice exercises, as Bob Hoover would agree.

Don't even think of using this for navigation.
Everything started off rather uneventfully. I tuned the Nav 1 radio to I-MFR and the Nav 2 radio to the OED VOR, which is the way I like to set up the radios when I'm flying an arc to an ILS or localizer.

I selected the OED 216 radial on the OBS, then loaded the approach into the GPS to use for a backup and a situational awarness cross-check. Since FSX isn't perfect, it didn't have WISEP intersection, but it did have one called D216X, which is the same thing.

It all looked good so far, so I took off and made a straight-out departure. I kept climbing until I intercepted the outbound radial, turned left, and kept on climbing to 9800, which is the minimum altitude for the procedure turn. Another 20 miles of seemingly straightforward flight followed on the way to the 24 miles from OED mark, which is where the DME arc was supposed to begin.

Both of those are tuned correctly. So why aren't things adding up?
However, as the distance increased and WISEP/D216X got closer, the needle wasn't doing quite what I thought it should be doing. It wasn't off by enough to be blatantly wrong; instead, it was just enough to make something in my intuition tell me something wasn't adding up, but not enough to ring any alarm bells.

I chalked it up to me perhaps being rusty, since this was only the second time this year I've shot a DME arc. After all, arcs are extremely rare nowadays, since you'll almost always get radar vectors instead. Of course, the thought that I hadn't even started the arc yet, so it couldn't just be that, hadn't occurred to me at the time. Hindsight is 20/20.

By the time I'm getting to about a mile away from the point where I should be starting the sharp left turn to begin the arc, things have really begun to not add up, and I'm really starting to get a bit confused. The GPS shows that I'm already past that point, yet the DME still says I have 0.7 miles to go!

The GPS claims I'm a mile past the beginning of the arc, but the DME says I'm only 23.3 miles out. Obviously, the GPS is wrong, because I could never make a mistake like that.
I dismissed that as having something to with FSX's database not having WISEP, so maybe the rest of the procedure was off by a little bit in the database. To make matters worse (or, more accurately, to make it easier for me to talk myself into believing that), there is an unlabeled intersection (the triangle on the GPS that the top of the red oval cuts through) almost exactly where I made up my mind that WISEP should be.

So just before I reached 24.0 DME, I began my left turn. I added in 10 degrees of right crab to compensate for the 20 knots of almost direct crosswind. This should have kept me from being blown inside the arc. It didn't, so I added five more degrees. Still getting blown inside. Added five more. Still getting blown inside. Added 10 more degrees of crab just to claw my way back to 24.0 miles. By this point, where I think my heading should be and what I have selected on the VOR disagree with each other by quite a bit.

After some effort, I've gone about halfway through the arc and have it bracketed well enough that I'm doing a good job being "on course". Unfortunately, at the halfway point, instead of fighting to keep from being blown inside the arc, I'm starting to drift further and further outside the arc, even though my heading "should" be correct. By the time I've figured out how to keep it from getting worse (which means I'm only halfway to figuring out how to fix it), my lead radial is only 10 degrees away.

A lead radial is something that tells you when you're getting close to the end of your arc and will be making your next sharp turn inbound. Ideally, if you do everything perfectly, you've sacrificed the right amount of chickens, and the stars are in perfect alignment, as you finish your turn, you'll roll out exactly on your inbound course.

Not this time. As the lead radial centered, I began a standard rate turn inbound. I rolled out on my inbound heading, but the Nav 1 display showed that I was way left of course. If anything, I should be right of course because the wind is now off my left side. No problem, easy to fix, and in just a few moments I'm back on course. For the first time, I'm actually on course and don't have to add scare quotes around it.

So I look at the chart to verify my stepdown points. I notice almost immediately that what I had read as 9800 feet is actually 9300 feet, so I'm already 500 feet high. Not a big deal, since I still have several miles to get down to 9300. But after that came the facepalm moment that explained the last half hour of confusion.

I double-checked to make sure my stepdown fixes were off the localizer's DME and not the VOR's. Then, like a good instrument pilot should, I verified that I had the correct DME source selected. Then it all made sense: after I tuned the Nav 2 radio to the VOR before takeoff, I never switched the DME source to Nav 2.

The entire time, I had been flying a ragged 24-DME arc off the localizer, not the VOR! Those two things are almost seven miles apart, as this shot from SkyVector shows:

Who's the idiot who decided to put the VOR at the top of the big hill instead of on the airport? (Oh, wait, that's where it's supposed to go. Signal propagation and all that.)
So I went back to where the GPS said I was past where I should have been but the DME said I hadn't reached it yet. I flipped the source switch to Nav 2 like it should have been the whole time, and lo and behold, the GPS wasn't lying to me—I was lying to myself. Quite convincingly, too, since now I was obviously 0.8 miles past where I was supposed to be.

It's only one little switch. How much difference could it make?

So you can see why I didn't get all smug when a professional aircrew landed at the wrong airport. Mistakes can and do happen to all of us. After all, I'm not a new instrument pilot; I'm a CFII with a decent amount of experience, and as you can see, I'm not invulnerable either.

In real life, this wouldn't have gone on as long as it did, because a real controller would eventually have asked why I was several miles away from where I should have been, and I wouldn't have so quickly dismissed the disagreement between the DME and the GPS. If this had happened to me in a real aircraft, I would have coupled the autopilot to the GPS and let it fly the arc while I figured out the problem. When you have a safe altitude, as is the case here, shedding some of the mental load to the autopilot lets you free up some of your mental resources to think things through. Just don't use the autopilot to do your thinking for you.

Humans make mistakes all the time; you just don't hear about them in the news every day because they didn't hurt anything except someone's pride. In fact, as Tom Turner over at Mastery Flight Training pointed out after the 747 at Jabara incident, an Antonov AN-124, which is a huge cargo aircraft that is almost as big as the 747, did exactly the same thing a decade ago. You just never heard about that one because they turned around and took right off again, since they needed a lot less runway.

The crew of National Airlines Flight 193 (for just one example of many) ignored the signs that something wasn't quite right and they ended up putting a perfectly-good 727 in the water, killing 3 people and injuring 11. So when things don't add up, don't just blithely continue on and pretend that reality is wrong because you just have to be right. That's just one more way that flight lessons make good life lessons, even if you're learning those lessons the hard way.


Tuesday, December 17, 2013

Ten for 110: Ten things you might not know about the Wright brothers

Today, December 17, 2013, marks 110 years since the Wright brothers first flew at Kitty Hawk, North Carolina. The world changed that day (although since Twitter wouldn't be invented until about a century later, the world wouldn't realize it for a while:), and while the world of aviation has changed immensely since then, its core fundamentals haven't. People still need to connect face-to-face even in the age of Skype, and people still have an almost innate sense of longing to look down on the world from above.

To celebrate 110 years of flight, here are 10 things you might not already know about the Wrights:

1. The Wrights' first flight lasted 12 seconds and the distance of their flight was barely over half the wingspan of a modern Boeing 747: 120 feet for the flight, 211 feet for a 747-400.

2. They made three more flights that day. With practice, they got better, as they covered 175, 200, and 852 feet. (Not bad for people who didn't have a flight instructor, since the position didn't exist yet.) However, the last flight of the day ended up in a crash, which did some minor damage to the aircraft but left Wilbur uninjured. This did not make them the first to crash an airplane, though, because several people had tried to make airplanes before, most of which crashed. The Wrights weren't the first to build an aircraft; they were just the first to build one that worked.

3. It would be almost five years before the first fatal airplane crash. That dubious distinction goes to Thomas Selfridge, who died in the crash of a Wright Flyer. At the controls? Orville Wright.

4. Early pilot's licenses were signed by Orville Wright. (As I write this, there is one on eBay from 1927 which is going for $17,500.) When the FAA changed to plastic, credit-card sized licenses from the old paper ones, they picked a design that has a 747 on the front and the Wright brothers on the back.



5. Charles E. Taylor was the mechanic for the Wright brothers. Pilot's licenses have the Wright brothers on the back; aircraft mechanics' licenses issued since the beginning of 2013 have Charles Taylor's picture on them.

6. The picture that almost everyone has seen of that day on Kill Devil Hill was taken by John T. Daniels, who until that day had never touched a camera before in his life. Three of the flights (1, 3, and 4) were photographed. (Daniels was probably busy talking the world's first selfie during the second flight. Those took a lot longer back then because cell phones hadn't been invented yet.)

The original picture, straight from the Library of Congress. The image you're probably used to seeing is a version that has been cleaned up, processed, and prettified. Orville is flying and that's Wilbur standing next to the aircraft.

7. The unfortunate term "stall" was also due to the Wrights. They referred to the wing losing lift as a stall, which to this day confuses non-aviators into thinking the engine quit. A wing stall (or "aerodynamic stall") has absolutely nothing to do with the engine. If the engine quits, pilots usually refer to it as an engine failure because it's easier to type than "%@$#!".

8. After the Wright brothers' successful flight, aviation research in the United States stalled because they started to sue anyone who tried to make a better airplane in the U.S. That is a big reason why you learn French terms like "empennage" and "aileron" instead of "tail section" and "wiggly thing on the end of the wing": since the Wrights sued their American competitors, much of the progress in aviation for the next couple of decades would take place in Europe, out of the reach of American courts. That makes them patent trolls almost 100 years before the term was invented. Not the sort of thing history books tend to cover.

9. Alexander Graham Bell, who is well known as the inventor of the telephone, is also in the Aviation Hall of Fame. He was part of the Aerial Experiment Association, a group that conducted research into what would eventually become the aileron we know and love. Bell's research started approximately five years before the Wrights' first flight, and one of the AEA's main members, Glenn Curtiss, was later sued by the Wrights.

10. Just two months before the Wrights flew at Kitty Hawk, the New York Times ran an editorial saying that it would take somewhere between 1-10 million years before man would fly. They were only off by 1-10 million years. Considering it only took 44 years to go from the first flight to the first supersonic flight and then 22 more years to land on the moon, I can't even imagine what aviation will look like a million years from now.

Bonus: Wilbur, who like his brother stayed a bachelor all his life, was the first man to say that he "did not have time for both a wife and an airplane."

Although the 1903 first flight is the most famous, it wasn't until September 20th, 1904 that the Wrights successfully took off, turned, and landed back at the same field. The first written eyewitness account of this was published not in a leading science publication or Gizmodo, but in an article by Amos Ivey Root in the journal Gleanings in Bee Culture.

Saturday, December 14, 2013

Flying China's "Smog Road"

If you're an instrument-rated pilot, you're quite familiar with flying an ILS, since you have to perform at least one on your checkride. If you are or were one of my flight students, you know what one is, too, since I use part of the 3 hours of required instrument time to introduce the concept of the ILS because it may save your hide in a worst-case scenario.

In both of those cases, the ILS you're familiar with is called a Category I. It is by far the most common, and has altitude minimums of 200 feet AGL and visibility minumums of 1/2 mile. This one is so common that almost no one calls it a Category I (or "Cat 1" for short); it's just plain old "ILS".

However, at bigger airports, there are two higher categories available, called, logically enough, Category II and Category III ("Cat 2" and "Cat 3"). Unless you're an airline pilot or a professional at the controls of a go-fast machine, you've probably never flown one of these. That's because the airplane has to have more expensive equipment and the crew has more expensive training (and currency) requirements.

Except for the equipment and training required, Cat II isn't particularly different from a regular ILS, except it allows lower minima. It isn't talked about much because it is wedged between the ubiquitous Cat I and the glory-hog Cat III, which allows for autoland at zero-zero minumums. That's right: the plane can land itself without the pilots being able to see the runway.

Check out this example of an Airbus A320 landing itself. If it seems like the video is broken because it's all black, that's because that's the view out the window:



What does this have to do with the price of smog in China? Well, according to this article from Weather Underground, the smog in Beijing has grown so bad that it alone is causing an enormous amount of delays. It's so bad that the Civil Aviation Administration of China is going to mandate that airline pilots flying into Beijing be certified to fly autoland approaches by the beginning of 2014.

Think the smog can't really be that bad? Check out this picture from the story:


That's not fog, that's smog!

Thursday, December 12, 2013

The Driver's License Medical

AOPA had big (and good) news today with this announcement that a bill proposing to eliminate the third class medical requirement for many types of common flying has been introduced in the House of Representatives. What does this mean, and why did it happen?

What is in the bill?

The bill itself is so short that I've included it at the bottom of this post. In short(er), it will allow pilots to fly aircraft with 6 seats or less on noncommercial flights in good weather conditions below 14,000 feet without having to have any medical certificate besides a driver's license. In effect, it renders the third class medical obsolete for the majority of small aircraft pilots.

The bill is short because it's just being introduced. It's not even close to being law at this point; this is just the first step. The final legislation, once it goes through the gears of Congress, will likely look much different. Nonetheless, this is an excellent start at getting rid of an extremely outdated and ineffective requirement.

What is a third class medical?

There are three kinds of medical certificate, cleverly named the First, Second, and Third class. The medical requirements are rather stringent for a first, somewhat less demanding for a second, and the third is very similar to a routine physical you might already be getting from your doctor.

Who does this affect?

Airline pilots require a first class, smaller commercial operations (some charters, dropping skydivers, aerial photography, and other miscellaneous for-hire flying activities) require a second class, and everyone else currently needs a third class medical.

This bill won't affect airline/commercial operators at all. The only change it will make will be for the "everyone else" category. If this bill does pass, you will no longer need to have an FAA medical to hop in a 172 and fly a half an hour away to get a $100 hamburger.

Does this mean you can fly with just a driver's license?

No, you still need a pilot's license to fly. You just wouldn't need both a pilot's license AND a medical certificate if you're flying small airplanes noncommercially.

What if I've been taking/going to take flying lessons?

This means that you won't need to see a doctor to get your license, but you'll still need to go to your local FAA office and get a student pilot's certificate. As it is right now, the student pilot certificate is commonly combined with the medical certificate, so you can get both at once. Sport pilot students have been getting their student pilot certificate from the FAA office (or a Designated Pilot Examiner) ever since the Sport Pilot certificate was created.

What if I give flying lessons?

Flight instruction has always been in an odd no-man's land between commercial and non-commercial flying. It's a rare thing that you can take money for, but not be considered "for hire". If you're giving instruction to someone who already is a pilot, you don't even need a medical right now. This would probably extend that no not needing one at all, but I wouldn't exactly count on that. The FAA will probably issue a letter of interpretation once the process is done. In short, if the FAA keeps the attitude they have now, you won't need a medical at all any more to give primary instruction.

Can I still get a third class medical?

Sure you can, if you want to spend the time and money for some reason. You just wouldn't have to unless you fly IFR, you have a pressurized aircraft that you fly higher than 14,000 feet, etc.

How does this affect safety?

For a decade, there has been a whole category of pilots who do not need an FAA medical: the Sport Pilot. Sport pilots are limited to two-seat aircraft, can only fly during the day below 10,000 feet, and have a few other restrictions. The years since this category of certificate was created have given us time to collect data as to the effectiveness of the third class medical.

Now that the data is in, the results are clear: there have been exactly ZERO accidents due to medical factors in sport pilots. That's right: not a single one. That is doubly impressive considering the majority of people flying light sport aircraft are older pilots who decided not to renew their medical. That means that the "highest risk" group has turned out to be an imaginary risk.

The idea of having one group of individuals need medical certification to do something similar to what one group can do without certification isn't new. In fact, you do it every day! You can hop in your car and drive on the freeway all day with nothing more than a driver's license. However, each semi that you pass is driven by someone who had to pass a medical. Getting rid of some of the third class medical requirements makes aviation more closely align with driving, which is something almost everyone has experience with and causes no one any worry.

Does this mean there would be no medical requirements at all?

Far from it. It means that the requirements would be more efficient. As it stands now, all that is required for a third class medical is a basic checkup from an FAA-approved doctor who may not (and probably won't) see you again for 2-5 years. That's not much more stringent than the medical requirements to renew a driver's license every 4 years (in Ohio; your state may be different). Since your driver's license is your medical certificate to fly, if your driver's license is suspended for any reason (such as drunk driving), your flying privileges are, too.

Even under the current system, before every flight, pilots are self-certifying that they are in proper condition to fly. This will not change. If you develop a condition that would affect your physical ability to fly safely, or you're taking medication that would affect it (like strong cold medicine, painkillers, etc.), you're not legal to fly with or without a medical certificate.

If you get into an accident due to a medical factor (remember: this hasn't happened at all with the Sport Pilot category), it will still be your fault, just as it is today. This bill would make that even more clear, because you won't even have the excuse "I just got a medical certificate last year and I was fine then!" to try to fall back on. One suggestion that AOPA made when petitioning the FAA to make this change years ago was to require an annual (I'd prefer biennial) online class about how you can determine your fitness to fly. I'd support that, and I'd roll it into the biennial flight review requirements to make it simple.

Why did this bill get introduced?

AOPA and EAA, the two major grassroots aviation organizations, have been trying to get the FAA to extend sport-like privileges to private pilots flying small aircraft for several years. The FAA has passive-aggressively been stalling and claiming lack of data ever since. It has been becoming clearer and clearer that the FAA is unwilling to make any move without a cattle prod. This bill is that cattle prod, and considering that this bill goes way past the small changes the alphabet groups were asking for, it's a pretty high-voltage prod at that.

I'm no beltway insider, but I wouldn't be surprised if the reason the bill goes far past what they were asking for is so that when it gets negotiated down, the end result will be effectively sport pilot privileges. Asking for more gives the FAA room to save face by narrowing it to just that while giving AOPA/EAA/Joe Pilot what they really wanted anyway. The secret to good negotiation is letting everyone be able to get up from the table feeling like their side won, and this bill gives ample room for that.

The proposed bill:

A BILL
To direct the Administrator of the Federal Aviation Administration to issue or revise regulations with respect to the medical certification of certain small aircraft pilots, and for other purposes.

Be it enacted by the Senate and House of Representatives of the United States of America in Congress assembled,

SECTION 1. SHORT TITLE.

This Act may be cited as the ‘‘General Aviation Pilot Protection Act of 2013’’.

SEC. 2. MEDICAL CERTIFICATION OF CERTAIN SMALL AIRCRAFT PILOTS.

(a) IN GENERAL.—Not later than 180 days after the date of enactment of this Act, the Administrator of the Federal Aviation Administration shall issue or revise medical certification regulations to ensure that an individual may operate as pilot in command of a covered aircraft without regard to any medical certification or proof of health requirement otherwise applicable under Federal law if—

(1) the individual possesses a valid State driver’s license and complies with any medical requirement associated with that license;
(2) the individual is transporting not more than 5 passengers;
(3) the individual is operating under visual flight rules; and
(4) the relevant flight, including each portion thereof, is not carried out—

(A) for compensation, including that no passenger or property on the flight is being carried for compensation;
(B) at an altitude that is more than 14,000 feet above mean sea level;
(C) outside the United States, unless authorized by the country in which the flight is conducted; or
(D) at a speed exceeding 250 knots.

(b) COVERED AIRCRAFT DEFINED.—In this section, the term "covered aircraft" means an aircraft that—
(1) is not authorized under Federal law to carry more than 6 occupants; and
(2) has a maximum certificated takeoff weight of not more than 6000 pounds.

SEC. 3. REPORT.
Not later than 5 years after the date of enactment of this Act, the Administrator of the Federal Aviation Administration shall submit to Congress a report that describes the impact that the regulations issued or revised under section 2 have had, including statistics with respect to changes in small aircraft activity and safety incidents.

Friday, December 6, 2013

Why you don't have to learn spins

Ron Rapp had a post a couple of days ago on mandating spin training. That's not unusual; in fact, it's so common that every time I come across yet another call for mandatory spin training I immediately think, "Ugh... This again?" The only reason I'm picking on this one is because his post was picked up by AOPA's newsletter and the topic has been in my "Big List O' Posts to Write Someday" file for a while now. Today's as good a someday as any.

Don't get me wrong about Ron; his posts are usually pretty good, and I even linked to his account of ATP's training program in a previous post of mine. Although in this case, he claims that it might have prevented 20 accidents last year. That's based on an oversimplistic search of accident records with no real thought as to whether those spin incidents would have realistically recoverable. I'd be willing to bet an expensive steak dinner that 0 of those 20 would be. In fact, I'm almost 40 years old, and I'd be willing to bet that in my entire lifetime, there aren't 20 pilots who would have been saved by mandating spin training.

Want to see what the typical unintentional spin event looks like? Check out this video and tell me if you think bringing back mandatory spin training would have saved the day:



The answer is no.

There are tons of people who think that pilots who trained waaaaaay back in the days of mandatory spin training are better off than the young whippersnappers who didn't. (I put six "a"s in way because the FAA realized six decades ago that spin training is counterproductive.) These are reminiscent of the "back in my day, when a pitcher got hit by a ball that knocked all his teeth out, he'd go right on pitching both sides of the doubleheader" stories that make Grampa famous. That's very nice, but nowadays we teach pitchers to duck, and that works even better.

We don't teach spins to initial students for the same reason we don't teach Russian Roulette in gun safety classes. The reason most often given for requiring spin training is that pilots should know how to handle it just in case they accidentally end up in one. That is like requiring Russian Roulette lessons "just in case" someone ends up pointing a gun at their own temple. Wouldn't it be a lot more effective just to teach people not to aim guns at themselves in the first place?

No stall = no spin. No putting a gun to your head = no chance of accidentally making yourself four inches shorter.

Not being uncoordinated in a stall = still no spin. Not putting two bullets in the gun = still no chance of accidentally making yourself four inches shorter.

 I can count the number of times I have entered an unintentional spin on one hand. For that matter, I can count it on no hands, because it has never happened. Why? Because I've never unintentionally stalled an airplane, either. No stall, no spin. Have I mentioned that last bit before?

Even when intentionally stalling, I have never ended up in a spin. Why? Because I use the rudder pedals. No uncoordination, no spin.

No spin, no spin recovery.

Are you starting to see a pattern here? A pattern of "no spin"? With no spin to recover from, no spin recovery technique is necessary. Train pilots not to get into situations that may lead them in to possible spin situations in the first place instead of how to get out of one. A pilot that got that far behind the airplane isn't likely to suddenly become Superpilot and unbury himself or herself just because they went up years ago and did a few spins. Especially when they're 400-600 feet AGL making a base-to-final turn or a poorly-executed climbout.

The FAA had good reason to drop the spin requirement. It wasn't because they were getting "soft", it was because the numbers just didn't add up to support keeping it. If the FAA thought that spin training was effective, they wouldn't have been shy about keeping it in. They crunched the numbers, figured out how many people were dying in spin training accidents during initial training, figured out how many spin accidents could have been recovered from, and ended up figuring out that more people were dying from the training itself than would have been saved by it. That's why the FAA doesn't require it, not because pilots suddenly became a bunch of spin sissies.

That said, I had to do spin training to become a CFI. That's not a bad idea. First, all CFI applicants are at least commercial pilots. That means they're not brand new students who are overwhelmed just trying to keep the airplane straight and level and within a couple hundred feet of the right altitude, so there is some mental storage space available to learn something from the experience. Second, student pilots, who haven't yet developed good rudder skills (that's why they're students, after all), are likely to get themselves—and by extension the instructor—into some spin-like states.

To this day, I feel that the spin training I had was some of the most valuable time I've had in my logbook. That's because I agree with Ron that a large part of the value of spin training is not the spins themselves but getting over the fear of the unknown. It pushed me out of my complacency zone and forward into a new zone where I was more confident in both my own abilities and the aircraft's.

Would it have been as valuable to me at 26 hours as it was at 260? Not a chance. Spin training does teach you many extremely valuable lessons, but they are also subtle ones; ones subtle enough that you need a decent level of skill before they'll have any value.

Should you take spin training? Absolutely! Should you have to take spin training as part of initial training? Absolutely not! I highly, highly recommend that once you've started to get a good handle on flying and you're starting to feel comfortable as a real Pilot In Command, go out and do some spin work with a good instructor. It will make you a better pilot; on that Ron and I do agree.

Thursday, November 28, 2013

Happy Thanksgiving

Thanksgiving day is a time when we have a chance to get together with friends and family and be thankful for the gifts we have received, both tangible and intangible, throughout the year.

The day before Thanksgiving is the busiest travel day of the year, and since many people fly themselves to spend time with family and friends on trips they wouldn't have been able to fit into a busy schedule otherwise, we should be grateful for the wonder of flight. To that end, check out this Bloom County from 1984 where Opus gives his rendition of John Gillespie Magee Junior's "High Flight" and appreciate that pilots can do something that a penguin can't.

Thank you, readers, for making another year of Keyboard and Rudder worthwhile. The best of the holiday to you and yours.

Thursday, November 21, 2013

How does a plane land at the wrong airport?

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A good friend sent me a story from CNN about a 747 that landed at the wrong airport last night and asked how it could happen. The short answer is that it's not as hard as it seems, especially under the circumstances.

For a while now, when teaching about situational awareness, I have used the example of this C-17 Globemaster crew that landed at Peter O. Knight airport in Tampa instead of MacDill Air Force Base where they had intended:


Thanks to the 747 crew, I have a second example of how easy it is to chase the wrong patch of concrete. Keep in mind that both of these examples happened to professional crews using modern equipment and avionics. (Update: USA today has a short rundown of how many times this has happened in just the last 10 years.)

When I started to read the story my friend sent me, I originally thought, "Oh, they must have landed at Mid-Continent instead thinking it was McConnell AFB. Both of them have long parallel runways heading in the same direction." I've been to Mid-Continent (center-left underneath the "WICHITA" below) and I remember when I was looking at the sectional chart during my flight planning I made a mental note as to how much McConnell looks like Mid-Continent and to double-check I was pointed at the right one once I got there.

Chart from vfrmap.com
Both of these incidents had several things in common:
  1. crew going to a military, towered field lands at a non-towered field
  2. runways in similar configuration
  3. you actually heard about it happening
Regarding (1), until I had a chance to spend a lot of time in a control tower taking students for visits to one, I wondered how the person in the tower wouldn't have gotten a wee bit concerned about why the plane's altitude was so much lower than one would expect if they were landing at the correct airport. After seeing how they operate and getting a better understanding of their place within the system, I can see how such a thing could be missed.

Tower controllers have lots of other things they're doing at the same time. The usual depiction of controllers as people staring at a radar screen unblinkingly with nothing else in front of them is only true of either center controllers or approach controllers. You've seen these time after time, including in the funny but underappreciated movie Pushing Tin with John Cusack, Billy Bob Thornton, and Angelina Jolie:



That stereotypical image isn't even remotely true of tower controllers because their job isn't to get aircraft from Point A to Point B. The aircraft has already made it almost to Point B and their job is to sequence them in line with other aircraft that may already be landing (or waiting to take off), and it's up to the pilot to actually land it. They might notice if the aircraft's blip (called a data block) drops off the radar early, but in this case they were in an area where radar coverage goes all the way to the ground (as the dotted magenta line surrounding AAO, the airport the 747 crew landed at, shows above). If the aircraft is in distress or the pilot tells the tower controller on initial contact that they're a student pilot, the controller will watch the display very closely, but for a routine flight flown by a highly experienced crew (no one just hops into one of the front seats of a 747 without thousands and thousands of hours) in the middle of the night with no other traffic around, its very easy to see why this wouldn't be noticed. After all, controllers can't fly the airplane, and they expect the people who are to do the job right.

Regarding (2), the only thing that surprised me about the C-17 in Tampa is that it hadn't happened even earlier or more often. Peter O. Knight looks much like a miniature version of MacDill, and it is directly in line for final with one of MacDill's runways. This is very similar to an environment the 747 crew was put in, as you can see by this sectional chart excerpt:

Chart from vfrmap.com

In the Wichita chart excerpt above, I drew a cyan line connecting the two to emphasize how both runways go in the same direction and line up with the flight path of the 747 almost perfectly. At any time, but especially at night, these airports wouldn't look all that different from one another. Since I don't have the time to hop in the plane and fly the 700+ miles to take a good, real picture, here's a view of what the arrangement looks like at night in Microsoft Flight Simulator X from an altitude and distance they were likely to be at:

Click image to embiggen.

There's the airport they landed at, from 4,000 feet and 10 miles out, which is my best educated guess at where they were. (Update 11/22: I dug up the flight's track log on FlightAware and that was one outstanding guess. That's pretty close to where they were at one point.) Did you notice the darker patch in the background? Yeah, they probably didn't either. That's because they were in the right vicinity, the heading was about right, the altitude was about right, and there was an airport right about where one should be. With that in mind, once the pilot flying saw the airport, his mind locked on to it and he concentrated only on flying safely down to it. Once the airport is in sight, even GPS or the FMS gets ignored, because the point of navigation systems is to get you to the point where you have the airport in sight.

The concentration required on approach forces the mind into a sort of tunnel vision. This isn't something that more training would fix, and it's not something only a "stupid" pilot would do: this is a basic, unavoidable fact of human nature and the human brain. Screening out distractions and focusing solely on the task at hand is an excellent skill and one of the things that makes a good pilot a good pilot. Unfortunately, in this case, one of the "distractions" was the airport he actually meant to land at.

I've had flight students take me to the wrong county before, even when there is no other airport within 20 miles. That's because I sprung an "emergency" diversion on them right in the middle of their nicely-planned cross-country flight, they focused on an airport that they thought was the one I told them to divert to, and concentrated on flying to the airport they saw. It wouldn't be hard to go to the wrong one when there are 4 airports within 10 miles that all look a lot alike, as is the case with the 747 crew here.

Regarding (3), this doesn't happen every day or every month, but it does happen plenty of times that you don't hear about. Many general aviation pilots have picked the wrong airport, and small regional airliners have done the same on several occasions. The difference with them is that because they're much smaller aircraft, they simply blush, taxi back to the ample runway, and take off again without anyone ever being the wiser. (Except in the case of the regional airliners, because the onboard ACARS or similar system automatically reports landing and takeoff events to the airline office, so those pilots might get a bit of a raised eyebrow from the company without making headlines.)

Another friend pointed out this incident from NASA's Callback bulletin from October 2004 called "Lost, Alone, and in the Dark" that you probably didn't hear about because it didn't make the news:
I preflighted the plane for a return flight to [another airport in Wisconsin]. The lighting on the instrument panel seemed faint, but the airport ramp was well lit. I adjusted the rheostat on the panel and departed. Once aloft, I could not easily read the instruments. Relying only on the compass, I became lost. I could not read the clock and lost track of time. After searching for an airport to put the plane down, I saw one with a runway open. I saw a plane approaching and, maintaining a safe distance, followed it in and landed. I took the first taxiway off the runway and shut down. I had not declared an emergency and was not in contact with the tower. It was O'Hare.

In the end, the Air Force concluded its investigation of the C-17 incident by stating the cause as pilot fatigue. While it will be quite some time before the facts of this current incident come out, I suspect that in the end the final cause will boil down to a simple matter of human imperfection. It's easy to second-guess and Monday morning QB, but in reality good pilots are always trying to learn from the mistakes of others (you can't live long enough to make all of them yourself) without copping an attitude of, "That would never happen to me." That's a lesson that—like so may others—transfers well from the cockpit to everyday life.

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 FAASafety Team representative and Master-level participant in the FAA's WINGS program. 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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Tuesday, November 19, 2013

Storm Kings from Mars

Review of Lee Sandlin's Storm Kings: The Untold History of America's First Tornado Chasers

METARs, TAFs, and other sources of aviation weather give the heights of cloud bases, but they do not give any information about what kind of clouds they are. The sole exception that you're likely to see is CB—cumulonimbus. After all, thunderstorms are important to know about because you don't want to fly into one. However, there is another exception, one that you're unlikely to see in your average everyday flying: FC—funnel cloud. Lee Sandlin's book is all over these and the people who study them, chase them, and obsess about them.

Ben Franklin is known for many things, and one of the images that probably comes to mind when you think of the name is the painting of him performing the famous key on a kite experiment. What you may not have known is that the author of Poor Richard's Almanack was also the author of studies on tornadoes and waterspouts, making him one of the founders of what would eventually become the modern science (and Weather Channel overdramatization) of storm chasing.

From one of Franklin's studies called "Water-spouts and Whirlwinds".
Photo from NOAA's Photo Library at http://www.flickr.com/photos/noaaphotolib/
Sandlin moves deftly from Franklin to other major players in the birth of storm chasing (and, for that matter, weather prediction in general) such as James Espy, William Redfield, John Finley, Cleveland Abbe, E. J. Fawbush, Robert Miller, Ted Fujita, and others. He does not pretend that science is an impartial, unstoppable march where the success of ideas is solely due to the strength of the data that back them, but gets into the personalities, and the conflicts between those personalities, that gave shape to the early studies and debates.

Along the way, he takes us on visits to the trails of destruction left by tornadoes, which were then known as "wind roads" as they cut passages through the thickly-wooded lands of the early United States. Until the invention of the airplane, research on these was only able to be done slowly by painstakingly walking them and taking notes on the arrangement of debris. Ted Fujita (the "F" in "EF-5 tornado") was able to make much of the progress that he made by utilizing Cessna planes to fly him along these trails.

Sandlin gives us an account of the Peshtigo firestorm which spawned tornadoes of flame, incinerating villages and killing more people than any other fire in U.S. history. (The fire made the public relations blunder of happening on the same day as the Great Chicago Fire, which is why it's likely you've never heard of it despite its apocalyptic style.)

He drops in on Tinker Air Force Base and relates the story of the first successful prediction of a tornado, takes us to the Weather Bureau when it fit in a single unremarkable building, and recounts the damage done by several different tornadoes of historical proportions, and does almost all of it so well, with such good tie-in, that it's almost as much of a page-turner as a fiction novel would be.

In fact, the only real complaint is that once we go on this tour through a few centuries of storm-chasing history, he closes up shop and turns off the lights as soon as we get to the present day storm chasers. I can't fault him overly much for this for two reasons. First, there are several books already on the market about modern storm chasing, many of them written by the chasers themselves. Second, the book, by its very title, is intended to be a history of storm chasing, which means its subject matter excludes the present. True to form, almost the only mention made of modern storm chasing is in a rather short epilogue.

Summary: A fast read that is surprisingly entertaining for a history book. If you buy it through the link below, you help support Keyboard & Rudder at no cost to you:

What Sandlin left out was that tornadoes also happen on Mars. They even leave their own "wind roads", though theirs are through the dusty surface of the red planet instead of fallen trees. Check out the two images below for proof of extraterrestrial tornadoes:
The arrow is pointing at a Martian dust devil.
See http://hirise.lpl.arizona.edu/PSP_004285_1375 for more information.




The black squiggles are Martian "wind roads" created by dust devils as they wandered the surface, kicked up dust, and faded away.
See http://hirise.lpl.arizona.edu/ESP_013538_1230 for more information.

Friday, November 15, 2013

Man Dead After Falling Out of Airplane

A man in South Florida is feared to be dead after the door opened in the Piper Malibu he was flying in as a passenger on Thursday. Makes for great copy and an even better headline, but would it really happen? Not on your life (or his).

Despite what the movies would have you believe, even in the extremely rare cases when an entire section of fuselage rips off an airliner at over 30,000 feet, everyone inside doesn't get sucked out a big hole. In the even more rare cases that someone does get "sucked out", it is always someone like a flight attendant or other unlucky soul who happened to be standing up, unbuckled, right next to the opening.

This "sucking" only continues until the pressure inside the fuselage (which is much higher, since the people inside tend to consider enough oxygen to breathe as included in the price of the ticket) equalizes with the pressure outside. If the hole is large enough for a person to go through, this equalization will take place in a matter of seconds. After that, all that loud noise and wind will be from air outside the aircraft coming in just like the wind does when you roll down the windows in your car. (That's assuming your car has 10-foot windows and is going 500 MPH.) Take comfort in the knowledge that in almost all cases of pressurization problems, the loss of cabin pressure is slow and is caused by either a stuck valve in the system itself or a gap that opened up somewhere in between the pressurized and unpressurized parts of the aircraft that is small enough that even a @#$% snake on a @#$% plane couldn't squeeze through.

The reason I put "sucking" in scare quotes above is because the air inside the plane isn't being "sucked" out. In reality, what is happening is that the higher-pressure air inside is flowing violently outside to where the pressure is much lower. It's exactly the same principle as what happens when you blow up a balloon then instead of tying the end, you let the air come out, making a noise that sounds like a session of Congress. If you let the air come out long enough, eventually all of it will be gone and it will stop flowing.

Now that I've spent three paragraphs explaining what happens in airliners, I'll get to the Piper Malibu referred to in the news story by saying that it has almost nothing in common with an airliner. Even if the entire top of the aircraft fell off, its service ceiling is about 10,000 feet lower than an airliner's typical cruising altitude so the difference in pressure between inside and outside is much lower, the cabin is much, much smaller so there's less air to "suck", and it goes less than half as fast. In addition, it has a "Door Unlatched" annunciator light in the cockpit, so the pilot wouldn't be able to take off with the door ajar without knowing it. (I mention that because the pilot reported that he had an open door.)

Will an airplane fly with a door open? You bet it will. In fact, I've had doors unlatch on me in flight dozens of times; it's just one of those things that happens occasionally. Most of them are designed—just like the doors on your car—so that if they do accidentally come unlatched the air flowing past the fuselage will keep them pressed mostly closed. The plane itself doesn't care, and it will keep on flying happily along with almost no noticeable difference other than a higher-than-normal level of cockpit noise and a nice cooling breeze along the forehead (in Cirrus and Piper aircraft).

In fact, this is such a common occurrence in Piper Seminoles that when I took my CFII checkride, I semi-jokingly included in my pre-takeoff briefing to the examiner: "Once the door pops open on the takeoff roll, I will bring both throttles to idle, contact tower to let them know we are aborting the takeoff, exit at Taxiway E, secure the door once we are clear of the runway, and ask to taxi back for takeoff again." Can you guess what happened one minute later? (To be fair, this doesn't happen all the time. I only said it because I knew that a quirk of the particular aircraft I was in that day was that its door latch was like Jay Leno: old, worn out, and desperately in need of replacement.)

When a student is getting close to solo in a Cirrus, I will intentionally pop the door open in the traffic pattern to see how they react. If they continue around the pattern, land, and then address the door, I know they are doing just fine. The first priority of an aviator is always, always, always, no matter what happens, always fly the plane.

An open door isn't even an emergency, but most manufacturers have a procedure to handle it just in case. This usually boils down to a simple matter of slowing to about 80 knots, opening a window, and closing the door again. It is considered such a minor matter than some manufacturers actually put the "Door open in flight" checklist in the "Normal Procedures" section of the manual. Piper is not one of those, but they do have a checklist for it. The first few lines of it are simply:

If both upper and side latches are open, the door will trail slightly open and airspeeds will be reduced slightly.

To close the door in flight.
Slow airplane to 82 KIAS.
Cabin vents ... close
Storm window ... open

Many aircraft will fly perfectly well even if a door is removed. Skydivers do that all the time, and I flew a Cessna 182 with the right door taken off when I dropped the famous Golden Knight turned motivational speaker Dana Bowman on one of his jumps in 2012. I could hardly tell a difference, other than with the weight of the right seat and door gone, the plane actually performed a bit better.

I'm not going to speculate on what actually happened in that Piper Malibu. That's for the investigators to figure out. All I'm here to do is to tell you what won't happen in an airplane: you won't fall out of one if you fly. So go out and enjoy it!

Thursday, November 14, 2013

House, you are cleared for takeoff

Several years ago, someone came up with the neat idea of taking a retired Boeing 747 out of the boneyard and making it into a house. A few closed highways later (747 wings don't exactly fit on the back of an F-150 pickup truck), and the house is now complete.

The results are more imaginative than just plopping an aircraft down on a lot, taking out the seats, putting in new carpet, and calling it done. Instead, this is a house that is made out of 747 parts, not just a 747 that was made into a house.

Architecturally, it is interesting in its own right, but what I find most interesting about it is actually being able to see the shape of the airfoil at the wing root. Since wings taper at the end, getting thinner and changing into a more flattened shape, and then hiding the rest of the aeronautical design in winglets at the tip, it is hard to see that the same Bernoulli-inspired design that you see in the generic textbook airfoil is also at the heart of the 747's wing.

Sometimes it's easy to forget that the same principles that apply to a little Cessna 172 also apply to a huge Boeing 747, but the pictures of this house make it blatantly obvious that they do. Physics is physics, and you can see that for yourself here with one of the coolest examples around at Houzz Tour: A Salvaged Airplane Becomes a Soaring Hillside Home.

Thursday, November 7, 2013

An Incredible Forecast from an Incredible Storm

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It was one year ago that Hurricane Sandy impacted the East Coast of the United States. Its incredible size allowed it to cause more damage than the average hurricane. Unlike many storms, whose effects are felt in a relatively more compact area, Hurricane Sandy unleashed her winds and precipitation over multiple states at the same time.

In fact, while New Jersey and New York were bracing for their direct hit, Hurricane Sandy was kicking up strong winds and rain all the way to Cleveland, Ohio. These winds and clouds caused some relatively minor (compared to NY/NJ) damage around the area and gave me a stretch of several days off from flying due to Terminal Area Forecasts (TAFs) such as this:

It's cold, rainy, and the winds are gusting to almost 50 knots. Let's not fly today.
I've had a few posts recently where I go into how to use a TAF and how not to. But what if you're still not sure what all that "secret code" means? Well, why don't we review how to read a TAF by decoding one you won't forget?

This screenshot is the combined METAR and TAF output from aviationweather.gov's lookup service. Where I fly, I usually pull up the forecasts for the two closest airports that have them to get a bigger, more accurate idea of what the weather is going to do, which is why this contains both KCLE (Cleveland-Hopkins) and KMFD (Mansfield-Lahm).

First the METAR:
KCLE 300251Z 34036G48KT 6SM +RA BR OVC014 06/04 A2951
I'll truncate the stuff beginning with RMK because while it's information that's "nice to know", it's not "need to know". I want to focus on the meat of the METAR without bogging you down in details.

KCLE: (Cleveland-Hopkins International Airport)
300251Z: Look at it as 30/0251Z - The 30th day of the month (October) at 2:51 a.m. Greenwich Mean Time (Zulu)

34036G48KT: Look at it as 340/36/G48 with a KT to remind you that it's knots. In other words, winds are from 340 (northwest; this is a true direction not magnetic, since this is a text report) at 36 knots with gusts (G) to 48 knots. That's 41-55 MPH. The light sport aircraft I was teaching in at the time would take off without moving in a wind like this.

6SM: The SM conveniently reminds you that this is something in statute miles. About the only thing ever given in aviation that isn't in nautical miles is visibility. Therefore, visibility 6 miles.

+RA: heavy (+) RAin

BR: mist. The reason it's not "MI" is because everybody hates Michigan so much that they'd rather use an abbreviation for the French word "brume", which means "mist".

OVC014: skies are OVerCast beginning at 1400 feet above ground level.

06/04: temperature 6° Celsius (43° Fahrenheit), dew point 4° C (39° F). The two numbers being so close usually means there will be some low clouds. That's kind of anti-climactic, since we just saw that the sky was totally covered in clouds (overcast) at only 1400 AGL.

A2951: Altimeter setting (i.e., the barometric pressure) 29.51" Hg. That's really low, especially considering Hurricane Sandy's center is hundreds of miles away.

Combining all these little facts into something useful, we can see that on the night of October 29-30, 2012, in Cleveland the weather was very chilly under solid clouds, and it was so windy that cats and small dogs were being blown away, then falling back to the ground as heavy rain. It's got to get better sometime, right?

That's where the TAF comes in. And then says, "Umm, no, actually."

KCLE 300253Z 3003/3106 35030G50KT P6SM -RA OVC015
   TEMPO 3003/3005 3SM RA SCT008 OVC015
   FM300500 34030G50KT 3SM RA BR OVC006
   FM301400 34025G40KT 4SM -RA BR OVC006
   FM302300 30018G30KT 5SM -RA BR OVC006

TAFs and METARs use similar terminology and format, so if you understand one, you understand about 80% of the other.

KCLE: (Cleveland-Hopkins International Airport)

300253Z: The date and time of a METAR are when the observation was taken. The date and time of a TAF are in the same format (in this case, the 30th day of the month at 2:53 a.m. Greenwich Mean Time) but are when the forecast was released.

3003/3106: Valid from the 30th at 3:00 a.m. Z to the 31st at 6:00 a.m. Z

35030G50KT: When this forecast was issued, the winds were from 350 (north) at 30 knots gusting to 50 knots.

P6SM: visibility is Plus (i.e., greater than) 6 statute miles

-RA: light (-) RAin

OVC015: skies are OVerCast beginning at 1500 feet above the ground

TEMPOrarily, from the 30th at 3:00 a.m. Z for the next two hours, it's going to get even worse. The visibility is going to decrease to only 3 statute miles, some scattered clouds are going to drop down around 800 feet above the ground and then it's going to be solid clouds starting at 1500 feet above the ground.

FRom the 30th at 5:00 a.m. Z, the winds are going to keep on blowing, the rain is going to become moderate instead of light, and it's going to stay cloudy, with the clouds coming down to 600 feet above the ground.

FRom the 30th at 2:00 p.m. Z, the wind is going to stay strong although slightly weaker, the visibility is still going to be cruddy but slightly better, and the rain is going to slightly but not completely let up.

FRom the 30th at 11:00 p.m. Z, ditto the preceding paragraph.

Condensing that forecast into something useful like we did with the METAR, we can see that the whole day is going to blow. Literally. To help you see just how much it blows, here are the surface analysis and weather depiction charts for that time:

Surface analysis for October 30, 2012 at 0300z. Hurricane Sandy stands out as the big L with the closely-spaced isobars surrounding it.

Weather depiction chart for October 30, 2012 at 0400z.