Archive for June, 2008

The Sky Is Blue

Posted in Uncategorized on June 28, 2008 by luckyjet

When I Became King for a Week

Posted in Uncategorized on June 24, 2008 by luckyjet

Day One: Changed the name of the Gulf Of Mexico to the Gulf Of Texas. Mexico complained a little but I told them they could rename the Gulf of California.

Day Two: Mexico still pissy about the “Gulf” thing, made some nasty remark about California being part of Mexico anyway. Then they sent another message about Texas being part of Mexico too. Told them to fuck off and speak better spanish. National speed limit changed to 50mph

Day Three: Truckers very unhappy. I.P.O. stock for my new railroad system goes way up.

Day four: Plan to use trains to carry loads of “debris”  and mud from New Orleans and the gulf of Texas to Arizona and return with loads of rock until flooding will never happen again is ridiculed by the press.

Day Five:”Methane Mountain” plan to use trainloads of poop from New York to make a mountain for gas fuel near the West Texas towns of Midland and Odessa hailed as genius. It turns out that New York poop smells better than Midland did before anyway.

Day Six: Truckers getting pissier by the day. Train stocks and airlines are doing well. Airline industry nationalized just for fun. Pilots really pissed off.

Day seven: Plan to eliminate airport security randomly for just a few minutes a day is hammered by the press. Oil exports stopped. OPEC is stunned, people be freakin. Pilots all go on strike. The airlines couldn’t afford fuel anyway. People riding the poo train for free.

Day Eight: Expected riots for grocerys, none happened. Seems everybody took a shit train to mexico and climbed the fence and headed south.

Maybe now I can rest, King is a hard job

Oh Yea, I almost forgot … Happy Landings.

What Makes It Go

Posted in Uncategorized on June 22, 2008 by luckyjet

Jet engines of one sort or another have been around since about 1942. The design has evolved considerably since the Luftwaffe was whizzing around amazing everybody but the basics are the same. Actually, only the very basics are the same. I’ll try to explain that part.

Only the core of a  modern jet engine has anything to do with fuel or combustion and all the machinery that makes so much noise and smoke. Most of the power comes from the fan part of the engine that never even gets the air hot.

The fan you see through the front of the engine is a giant propeller, it just has a lot of blades. This is where the name “Fan-Jet” or “Turbo-Fan” comes from. Older jet engines didn’t have the fan part and were just called “Turbo-jets”. On a windy day while the airplane is parked you can see the fan turning in the wind, even backwards if there is a tailwind. It makes a clacking sound, this is from the fan blades flopping around in their mounts and dragging against the outer edges. They are supposed to do that.

The fan is really efficient at moving a huge volume of air at relatively slow speed. This is important at low altitude where there is a lot of dense air to move. The turbo-jet core of a fan jet engine moves a small volume of air at super sonic speed. This is efficient only at high altitude. For this reason modern fan engines are much quieter and fuel efficient than the turbo-jets of 1960, especially at low altitude.

To understand a jet engine visualize a magic “stuff”.  Let’s call it air. Air is is really compressible. Squeezy, like a foam rubber sponge. Since we can’t see it in the first place this isn’t readily noticeable, and a little difficult to imagine.

The front part of a jet engine has a series of rotating discs of blades. Between each set of rotating blades is another set of blades that do not turn.  The rotating blades are mounted on a hollow drive-shaft.

Air coming in the front is compressed into a fluid with a very high oxygen content. Think of the air leaving the back of the compressor section as a volatile, unstable liquid. It would look like water if you could see it.

After the compressor is the burner section. Here fuel is metered through little injectors and mixed with the volatile compressed air liquid stuff. The resulting chemical reaction  is kind of amazing. Rapid expansion of the fuel/air mixture causes exhaust to jet out the back of the burner section like a rocket. Actually, it is a rocket. And a jet too. 

Here is the  pay off part. On the way out of the engine the exhaust gas turns another set of blades called “turbines” which also have stationary blades between them. The turbine blades are attached to … the same dang drive shaft that the compressor blades are driven by. Ain’t that just cooler than sheep dip! One section of the thing drives the other!  Wow.

Remember how I said the drive-shaft is hollow? The big fan on the front is attached to a separate drive-shaft rotating  inside the main one and is driven by a second set of turbines after the first set.

There is no ignition system used once the engine is started. The reaction of the fuel and compressed air is enough to keep the thing going. As a precaution during icing conditions or heavy rain, igniters are turned on that should help relight the engine if it should “un-start”.

The speed of the fan and core are allowed to be different and variable through this arrangement. This is why they often make that rung rung rung rung aaarung aarung  sound during cruise flight. It seems to work out just fine as far as the pilots can tell.

We control the power of the engine by limiting the amount of fuel available to it. On takeoff the CFM-56 engine of about 28,000 pounds of thrust uses more than 400 pounds of fuel per minute. Cruise power requires only about 50 pounds of fuel per minute per engine.

At average weights a flight will burn about 1,000 gallons the first hour, 800 gallons the second hour, and only about 150 gallons from cruise altitude to landing (with no delays).  We normally use pounds for fuel calculations since it is the mass of the fuel that the engines care about. A lighter fuel like ethanol would require many more gallons per hour but about the same number of pounds.

Since the compressor section produces an abundance of compressed air some of can be bled off and used to provide air for the cabin pressurization and wing or engine de-icing. It seems that if you have an abundance of compressed air it is fairly easy to heat or cool about anything.  The bleed air from the compressor is hot just because it has been compressed. 

The method of using hot air ( about 200 degrees F) to create cold air for cabin cooling is worthy of a article of its own. Most pilots don’t really understand it but they really don’t need to know why a system works if they know how to work the system. 

When the engines are used to help slow the plane on the ground the reverse thrust is created by ducting some of the thrust toward the front. This is done with sleeves that slide back and partially close off the exit of air from the engine and direct it forward. The engine doesn’t really start turning backwards, the air just gets blown forward.

Each engine drives fairly massive DC generator through an automatic transmission that runs at  constant speed. These provide enough electrical power for a few houses.

The bigger Boeings have engines as big around as the fuselage (body) of a 737. These are some really big air movers but the design is essentially the same.

The air doesn’t seem to mind too much what compresses it and moves along.

Happy landings

Clean Happy Work Enviornment

Posted in Airplanes n Stuff with tags on June 20, 2008 by luckyjet

How do you picture what’s behind the door while you are enjoying or enduring air travel as the case may be?

People generally seem to imagine the cockpit as a well designed, ergonomic, clean, comfortable, environment.  It ain’t. At least not in America.  Maybe in France or in one of those airbusters, but  not in the Boeing cockpit as it is fairly rustic. This doesn’t vary much from one airline to another.

Sharp corners are everywhere, dust is everywhere, things look clean only at first glance. Knobs and switches that get used a lot are usually really dirty. There is a special kind of crud that is part Mechanic hand grease, pilot booger and passenger lint that gets into every corner. And there are a lot of little corners. All of the knobs are designed for maximum finger traction and have little ridges. These couldn’t be more effective for gathering crud if they were designed for the purpose.

 

Airline Pilots are apparently sloppy people as a rule. Coffee, juice and Coke gets spilled and splashed all over everything. This provides a base layer for more lint and boogers. Pilots think nothing of sneezing all over the instrument panel and leaving snot everywhere. At night it doesn’t really show, but in intense daylight …….. everything shows.    I prefer to fly in the dark.

The sheepskin seat covers are great. Especially if nobody other than you ever sits in the seat. The problem is that on a hot day when someone else has been in the seat all day it gets kind of damp. I don’t find it invigorating to hop in and sit down on a dead sheep damp with somebody  else’s butt sweat.  Maybe I’m overly sensitive about this but it just isn’t my thing.

A good offset for the damp seat is the massive amount of paper they give us for each flight with the flight plan and weather printed on it. This makes a pretty good seat cover for the seat cover.

 The lint that collects in the cockpit changes color from Summer to Winter months. I think this is because passenger clothing is fuzzier during the winter.  Airplane boogers are even a different color in the winter too.

One of the very best things about the job is the view. It can also be one of the most challenging things about the job at sunrise and sunset since the only effective protection against intense sunlight at high altitude is a map or checklist card stuck in the window. 

There has been a subtle battle between aircraft design engineers, pilots, and the FAA (formerly the CAA) for the last eighty years or so in which the engineers try to provide an effective sun shade within government guidelines and the pilots find something else to use that actually works. Pilots are about a zillion thousand times more likely to get a bad case of exploding sunshine eyeball than anybody else. Engineers could just barely get people to the moon and back much less design an effective sun shade that isn’t illegal. The FAA has thier own ideas on how big a sun visor should be, but they all work in an office.

This is all nothing more than idle bitching, what I really wanted to tell you about is the view from my office. 

Twenty Miles Away

The windows are huge and I don’t have to lean over to see out. From about eight miles high the horizon is distinctly curved. A full moon is so bright I really do need sun glasses at night, and It’s easy to see five states as long as you aren’t in the middle of Texas.  It is also easy to see that a line of severe storms produces constant lightning.  On a clear night with a heavy undercast and no moon, leaning back in the seat I can see straight up.  Take it from me there are at least a zillion, zillion stars. 

2 or 3 States

The airlines are missing a huge opportunity to make money by not having an observation bubble in the top of the airplane and charging a dollar a minute to look outside.

Thank you all for your patience, I haven’t posted anything in a few weeks.  Enjoy the pictures.

 Happy landings.