Thursday, May 31, 2007

Aerosol in Contrails?

I hate to even give these guys a forum, but you can find a link to their conspiracy-minded lunatic ravings here. In short, they believe that the government has a secret program to poison or control the populace through aerosol dispersal of chemicals via airplane. They use photos like those found on this website as their "evidence."

Let me say unequivocally that there is no such program! Contrails are a natural phenomenon that occur when air at the right temperature and moisture content is passed through a jet engine. The advent of high-bypass turbojets (what you see on virtually all airliners these days) makes them even bigger. Within the contrails are signs they were produced by a large machine. This guy believes there are "cores" in the contrails. Those are caused by the engines themselves. High-bypass turbofans have two stages...the large fan stage that provides the vast majority of the thrust, and the smaller, but much hotter, core stage that provides the power to spin the fan stage. Both turn on the same axis with the N2 stage being interior to the N1 stage. With the right atmospheric conditions, the N2 stage (the smaller one) can create these secondary trails within the primary. There can also be a pattern of disruption from the wake turbulence from the wingtips. How they behave after creation has to do mostly with upper wind action. Every one of the pictures this guy shows can be explained. One thing's for sure...they really are neat pictures! But his conclusions are that of someone needing to wear an aluminum hat to protect himself from the aliens!

The specifics of any particular contrail has to do with the condition of the atmosphere in which the plane is flying. Thus this guy's "control photographs" are nothing more than a plane in different atmospheric conditions. I do know from time spent in NM that the skies there are often fabulously blue. There are also a multitude of jet airways that overlay the state. As a result, there are many days when the contrails are numerous and happen to stay around a while. There are other days when I fly when there are no contrails present. It's up to the atmosphere. Period. The altitudes at which you can expect contrails can actually be predicted. The military does this because a fighter certainly doesn't want a large white trail pointing the enemy to his plane! When in enemy territory, they will avoid the contrail altitudes in order to avoid easy detection.

And on top of that...we as pilots know our planes inside and out. This is necessary in order to deal with any malfunctions that occur. If there were actually something on our planes that would distribute this material into the air, we would know about it so we could deal with it in the event it malfunctioned. That would mean that there are tens of thousands of pilots who are all keeping their mouths shut. Oh...and then this device would have to be serviced, both in terms of regular maintenance and in terms of loading it with whatever this "chemical" is supposed to be. That would mean thousands upon thousands more people involved. It's getting really, really hard to keep a lid on such a "secret" program with that many people involved!

Sorry...enjoy the contrails in NM...but you have nothing to worry about but fluffy white water vapor!

Thursday, March 22, 2007

A Bad Day at JFK Ground Control....

Here is a link to a website that has a recording of a period of time at New York's JFK airport ground control. It's obviously a zoo, and the controller is barely keeping things straight. Remember this the next time you think your job is stressful!

Sunday, February 11, 2007

Avoiding Midairs

I had a commenter ask how we in the airline world avoid midair collisions. Given the number of planes in the air at any given time, that is certainly a valid question...and a valid concern! Obviously the result of one would ruin the day of a lot of people.

Except for a few remote places, airliners always operate under IFR (Instrument Flight Rules) and are under the direct observation and control of ATC (Air Traffic Control). They have very, very strict separation criteria and there are stiff penalties to be had for the controller should he allow that separation to be lost. We also fly at altitudes appropriate for our direction of flight. Eastbound flights are at odd altitudes; Westbound flights at even altitudes.

And when all else fails, airliners are equipped with Traffic Collision Avoidance Systems (TCAS). TCAS puts a protective "bubble of time" around the plane and monitors all other nearby traffic, predicting whether or not they will enter that bubble. If it appears they will, it alerts us to the traffic. If it becomes more probable, it actually commands a climb or a descent in order to avoid a collision. But even cooler is that if the offending aircraft is also TCAS equipped, my TCAS will coordinate with the TCAS on the offending plane so that both aircraft maneuver away from each other. These maneuvers are not abrupt; TCAS has undoubtedly already saved countless lives...and the passengers never even knew it!

Saturday, January 06, 2007


Depending on where you are flying, deicing can be a routine event. The FAA requires that planes not attempt to takeoff with anything adhering to the upper sides of the wings and tail (there is a minor exception for the underside of the wing) because it can significantly effect the ability of the wing to generate lift. The way this is accomplished is through the application of deicing fluid prior to departure.

Many larger airports in climates where deicing is a major event have setups where the plane taxis to a pad near the departure runway and is deiced with its engines running. That way, there is minimal time between the deicing and the takeoff. These pads are also usually designed to recover excess deicing fluid both for reuse (after reprocessing) and to prevent it from entering the surrounding environment through runoff.

Anything on the wing is initially taken off through the application of what is known as "Type I" fluid. This is a heated glycol/water mixture that is very effective at removing any contaminants from the wing. Unfortunately, though, it doesn't do much when it comes to further accumulation.

Enter "Type II" and "Type IV" fluids. Now these are very cool! Their viscosity is directly proportional to the speed of the air passing over them! This means that at slow wind speeds, this fluid is "sludgy" and sits on the wing. Any snow or ice accumulates on top of the fluid. At about 60 knots of speed during the takeoff roll, this "sludge" becomes "liquid" and shears off the wing, taking any accumulated ice and snow with it. This allows for much safer operations when there is significant snowfall.

So now you know a little more about what they are doing during the next blizzard in Denver!

Saturday, December 30, 2006

The Cascades in the Morning!

Departing out of Portland this morning, we had a spectacular view of the volcanic peaks of the Cascade range in the northwest United States. Below are several pictures I was able to snap.

When you fly, if you are not looking outside, you are missing out on many opportunities to see God's creation from a perspective you normally don't get. So... look outside!


The peak to the left is Mt. St. Helens, which erupted in the early 1980's. The peak on the right is Mt. Rainier, just southeast of Seattle. It doesn't look very big, but it's a long way away!

Mount Hood, just east of Portland, Oregon. Sadly, three climbers lost their lives on this mountain just a few weeks ago. Mt. Hood also hosts a ski area on a glacier...and many alpine racers from all over North America converge here in the summers to practice. Imagine skiing gates and dodging butterflies at the same time!

Saturday, December 16, 2006

Sunset over New York

Here are two pictures of a beautiful sunset as viewed from 38,000 over New York.

Enjoy...and praise God for the beauty of His creation!

Winglet Picture

I was able to get a great picture at the airport today that illustrates two different winglet configurations in a single shot. In the foreground is an Airbus A319 (about a third the size of the plane in the background!). You will note it's winglets are not very large, but they extend both upwards and downwards from the tip of the wing. In the background is a Boeing 747-400. It's winglets are huge and extend upwards at an angle. I'm sure there are aeronautical engineers out there who can expound upon the benefits of the different configurations, but suffice it to say that they increase the efficiency of the wing, which translates directly to fuel savings and increased range for the plane.

Friday, December 15, 2006

What's With the Winglets?

Since no one has asked a question recently, I thought I'd come up with my own.

Lately there has been a rash of modifications to planes, adding those large winglets. This isn't necessarily new. The 747-400 has had winglets since it was first produced as has the Airbus A320. So why are airlines suddenly spending considerable sums to equip their fleets with winglets? What do they do, other than look pretty cool?

As a wing moves through the air, the shape causes there to be higher pressure on the bottom than on the top. At the end of the wing that pressure escapes and tries to make it to the top. This causes small, horizontal tornadoes off the tip of each wing. These are known as "vortices." In high humidity conditions, you can sometimes see them. The thing about it is that, especially at slower speeds, these vortices cause a tremendous amount of drag, which in turn causes a much higher fuel consumption because the engines must compensate for the extra drag.

The addition of winglets interrupts the creation of these vortices. You can't stop them altogether, but you can reduce them...and any reduction in these tornadoes reduces the drag on the airplane...and any reduction in drag reduces the fuel consumption...and any reduction in fuel consumption reduces costs, and increases the range of the plane. A couple of airlines have added the winglets to 757's in order to increase their range to the point they can fly across the Atlantic.

I am going to try to get a couple of pictures of winglets to post for those who are still scratching their heads about what I am talking about.

Friday, December 01, 2006


In an earlier post, I noted that crop circles won out over Yosemite. Today I had the pleasure of flying right over Yosemite National Park and was able to get a beautiful shot that included both El Capitan and Half Dome. So I thought I'd post it here for you... and then you will understand my confusion at why the crop circles brought more interest on that previous flight!

1,000 MPH Closure

Here is a picture I took over Southern Colorado. We are at 39,000 feet and this USAir 757 is at 38,000 feet. Our closure rate is in the neighborhood of 1,000 miles per hour! Trust me when I say it is hard to keep the plane in the viewfinder of the camera!

Wednesday, November 15, 2006

Takes Your Breath Away!

I just had to post this picture as well, taken as we climbed out of Florida during sunrise. It almost makes it worth getting up at that horrendous hour! But it also makes for breathtaking amazement at the grandeur of God's creation!


Pilot Halo--The Answer

Here is a picture of a "pilot halo" taken a split-second before we descended into some clouds. The sun is directly behind us, so it focuses our shadow on the clouds in front of us. Then, for some reason beyond this particular pilot's ability to understand, the light refracts around the plane and places a circular rainbow around the shadow! ...thus the name "pilot halo." If the sun is on one side or the other and we are flying close enough to a deck of clouds, it will do the same, but from a profile angle... and you in the back would be able to see it as well!

Pilot Halo--The Question

There are those who think pilots' heads are already far too big for their hats! So now we're wearing halos???

It's not what you think... but you will have to wait until I can get a picture downloaded from my camera to see exactly what it is.

So...use your imagination, and see if you can figure out what I'm talking about.

Saturday, November 11, 2006

Ears and Pressure

One of my readers asked that I address the problem some people have with their ears when flying on airplanes. So...I'll try to oblige!

As anyone who actually listens to the flight attendant announcements knows, airplanes are pressurized. What that means is that the atmospheric pressure inside the airplane is kept at a level that human beings can tolerate. None of us would last very long at all if we were exposed to the pressure of 39,000 feet. It's not that there isn't enough oxygen there...the percentage is the same as at sea level. The problem is the partial pressure is so low that the oxygen molecules aren't pushed through the lung membranes into the bloodstream.

All that is beside the point of the question, though...

The planes are built to withstand a pressure difference between the inside and the outside of about 8 pounds per square inch. That translates to an altitude in the cabin of about 8,000 feet when the airplane is at 39,000 feet. So the most your body would have to endure is a pressure change from sea level to 8000 feet and back. Unfortunately, that's a lot...especially if your ears aren't clearing.

If your eustachian tubes and your ears are normal, and you don't have a cold, then the trip up and down is typically no big deal. But if you have any blockage of the eustachian tube, then you start to have a problem. Because of the way the tube is designed (it connects the inner ear to the throat, which equalizes the pressure between the outer and the inner ear), as you go up, the pressure on the inner ear increases relative to the outer ear. Even when the tube is constricted due to a cold, the pressure can escape. Think of it like a balloon and you are letting the pressure out. The problem comes when it is time to go down again. Now the pressure on the outer ear increases. With a normal tube, the pressure goes back into the inner ear as well, keeping them equal. But if there is any blockage, that pressure can't get back in...sort of like air trying to get back in the balloon by itself. That's where the pain occurs. In very serious cases, it can actually rupture the eardrum.

So what to do? (Keep in mind this isn't medical advice!!!)

Chewing gum sometimes helps in minor problems. Children crying actually helps as well. Pilots (and scuba divers) are taught to "valsalva." That means to hold your nose, close your mouth, and exhale strongly and forcefully. This forces the air through your eustachian tube and into the inner ear. When successful, you will feel the "pop" as well as the relief as the pressure is equalized. You will need to do this several times as the plane descends. If you can catch it before the pressure builds too high, it is far easier. One of the downsides is that a valsalva maneuver will also press some of the "guck" from your cold into the inner ear. You stand a much better chance of coming up with a subsequent ear infection.

Obviously a small child isn't going to be able to do the he has to just deal with the pain and cry, which might help. But if you understand what is going on, it helps you to have compassion on him during the descent and put up with the screaming (it's very, very painful).

Of course, if he's throwing a fit at any other time, then it's time to have compassion on the parent!!!

[P.S. (posted 12 Nov) There seems to be a misconception that smaller airplanes have a greater problem with ear difficulties than larger ones. Actually that's not the case. Both types of planes have similar pressurization ranges. A more reasonable generalization is older versus newer models of planes. As with everything else, newer planes have improved pressurization controllers, so the transition between the cabin pressure at altitude and the pressure at field elevation is smoother. Another reason this myth might persist is that most people fly on smaller planes far more than they fly on the larger ones, thus increasing their chances of having an ear issue when flying on a smaller plane.]