Aviation Incidents and Accidents

Posted by PITHOCRATES - March 12th, 2014

Technology 101

The Pilots of Aloha Airlines Flight 243 landed Safely after Fatigue Cracks caused Part of the Cabin to Disintegrate

The de Havilland Company introduced the jet airliner to the world.  The Comet.  A 4-engine jet airliner with a pressurized cabin that could carry 36 passengers.  It could fly at 40,000 feet at speeds close to 500 mph.  Just blowing the piston-engine competition away.  Until, that is, they started breaking up in flight.  A consequence of pressuring the cabin.  The inflating and deflating of the metal cabin fatiguing the metal of the cabin.  Until fatigue cracks appeared at stress points.  Cracks that extended from the cycles of pressurizing and depressurizing the cabin.  Until the cracks extended so much that the pressure inside the cabin blew through the cracks, disintegrating the plane in flight.

Japan is a nation of islands.  Connecting these islands together are airplanes.  They use jumbo jets like buses and commuter trains.  Packing them with 500+ passengers for short hops between the islands.  Putting far more pressurization cycles on these planes than typical long-haul 747 routes.  On August 12, 1985, Japan Airlines Flight 123 left Haneda Airport, Tokyo, for a routine flight to Osaka.  Shortly after takeoff as the cabin pressurized the rear pressure bulkhead failed (due to an improper repair splice of the pressure plate using a single row of rivets instead of a double row following a tail strike that damaged it).  The rapid force of the depressurization blew out through the tail section of the aircraft.  Causing great damage of the control surfaces.  And severing the lines in all four hydraulic systems.  Leaving the plane uncontrollable.  The crew switched their transponder to the emergency code 7700 and called in to declare an emergency.  But they could do little to save the plane.  The plane flew erratically and lost altitude until it crashed into a mountain.  Killing all but 4 of the 524 aboard.

Hawaii is similar to Japan.  They both have islands they interconnect with airplanes.  Putting a lot of pressurization cycles on these planes.  On April 28, 1988, Aloha Airlines Flight 243 left Hilo Airport bound for Honolulu.  Just as the Boeing 737 leveled off at 24,000 feet there was a loud explosive sound and a loud surge of air.  The pilots were thrown back in their seats in a violent and rapid decompression.  The flightdeck door was sucked away.  Looking behind them they could see the cabin ceiling in first class was no longer there (due to fatigue cracks radiating out from rivets that caused pressurized air to blow out, taking the ceiling and walls of the first class cabin with it).  They could see only blue sky.  They put on their oxygen masks and began an emergency descent.  The first officer switched the transponder to emergency code 7700.  The roar of air was so loud the pilots could barely hear each other as they shouted to each other or used the radio.  The flight controls were operable but not normal.  They even lost one of their two engines.  But the flight crew landed safely.  With the loss of only one life.  A flight attendant that was sucked out of the aircraft during the explosive decompression.

The Fact that 185 People survived the United Airlines 232 Crash is a Testament to the Extraordinary Skill of those Pilots

On June 12, 1972, American Airlines Flight 96 left Detroit Metropolitan Airport for Buffalo after arriving from Los Angeles.  The McDonnell Douglas DC-10 took on new living passengers in Detroit.  As well as one deceased passenger in a coffin.  Which was loaded in the rear cargo hold.  As the DC-10 approached 12,000 feet there was a loud explosive sound.  Then the flightdeck door was sucked away and the pilots were thrown back in their seats in an explosive decompression.  The aft cargo door (improperly latched—its design was later revised to prevent improperly latching in the future) had blown out as the cargo hold pressurized.  As it did the rapid decompression collapsed the floor above.  Into the control cabling.  The rudder was slammed fully left.  All three throttle levels slammed closed.  The elevator control was greatly inhibited.  The plane lost a lot of its flight controls but the pilots were able to bring the plane back to Detroit.  Using asymmetric thrust of the two wing-mounted engines and ailerons to compensate for the deflected rudder.  And both pilots pulling back hard on the yoke to move the elevator.  Due to the damage the approach was fast and low.  When they landed they applied reverse thrust to slow down the fast aircraft.  At that speed, though, the deflected rudder pulled them off the runway towards the terminal buildings.  By reapplying asymmetric thrust the pilot was able to straighten the aircraft out on the grass.  As the speed declined the rudder force decreased and the pilot was able to steer the plane back on the runway.  There was no loss of life.

On July 19, 1989, United Airlines Flight 232 took off from Stapleton International Airport in Denver for Chicago.  About an hour into the flight there was a loud bang from the rear of the plane.  The aircraft shuddered.  The instruments showed that the tail-mounted engine had failed.  As the crew responded to that the second officer saw something more alarming.  Hydraulic pressure and fluid quantity in the three hydraulic systems were falling (a fan disc in the tail-mounted engine disintegrating and exploded like shrapnel from an undetected manufacturing flaw, taking out the 3 hydraulic systems).  The flight crew soon discovered that they had lost all control of the airplane.  The plane was making a slight turn when the engine failed.  And the flight control surfaces were locked in that position.  The captain reduced power on the left engine to stop the plane from turning.  The two remaining engines became the only means of control they had.  Another DC-10 pilot traveling as a passenger came forward and offered his assistance.  He knelt on the floor behind the throttle levels and adjusted them continuously to regain control of the plane.  He tried to dampen the rising and falling of the plane (moving like a ship rolling on the ocean).  As well as turn the aircraft onto a course that would take them to an emergency landing at Sioux City.  They almost made it.  Unfortunately that rolling motion tipped the left wing down just before touchdown.  It struck the ground.  And caused the plane to roll and crash.  Killing 111 of the 296 aboard.  It was a remarkable feat of flying, though.  Which couldn’t be duplicated in the simulator given the same system failures.  As flight control by engine thrust alone cannot provide reliable flight control.  The fact that 185 people survived this crash is a testament to the extraordinary skill of those pilots.

On July 17, 1996, TWA Flight 800 took off from JFK Airport bound for Rome.  About 12 minutes into the flight the crew acknowledged air traffic control (ATC) instructions to climb to 15,000 feet.  It was the last anyone heard from TWA 800.  About 38 seconds later another airplane in the sky reported seeing an explosion and a fire ball falling into the water.  About where TWA 800 was.  ATC then tried to contact TWA 800.  “TWA800, Center…TWA eight zero zero, if you can hear Center, ident…TWA800, Center…TWA800, if you can hear Center, ident…TWA800, Center.”  There was no response.  The plane was there one minute and gone the next.  There was no distress call.  Nothing.  The crash investigation determined that an air-fuel mixture in the center fuel tank was heated by air conditioner units mounted below the tank, creating a high-pressure, explosive vapor in the tank that was ignited by an electrical spark.  The explosion broke the plane apart in flight killing all 230 aboard.

The Greatest Danger in Flying Today may be Pilots Trusting their Computers more than their Piloting Skills

On December 29, 1972, Eastern Airlines Flight 401 left JFK bound for Miami.  Flight 401 was a brand new Lockheed L-1011 TriStar.  One of the new wide-body jets to enter service along with the Boeing 747 and the McDonnell Douglas DC-10.  Not only was it big but it had the latest in automatic flight control systems.  As Flight 401 turned on final approach they lowered their landing gear.  When the three landing gear are down and locked for landing there are three green indicating lights displayed on the flightdeck on the first officer’s side.  On this night there were only 2 green lights.  Indicating that the nose wheel was not down.  So they contacted ATC with their problem and proceeded to circle the airport until they resolved the problem.  ATC told them to climb to 2000 feet.  The 1st officer flew the aircraft on the course around the airport.  The captain then tried to reach the indicating light to see if it was a burnt out lamp.  Then the flight engineer got involved.  As did the first officer after turning on the automatic altitude hold control.  Then another person on the flightdeck joined in.  That indicating lamp got everyone’s full attention.  Unable to determine if the lamp was burnt out the pilot instructed the flight engineer to climb down into the avionics bay below the flightdeck to visually confirm the nose gear was down and locked.  He reported that he couldn’t see it.  So the other guy on the flightdeck joined him.  During all of this someone bumped the yoke with enough pressure to release the automatic altitude hold but no one noticed.  The airplane began a gradual descent.  When they approached the ground a ground proximity warming went off and they checked their altitude.  Their altimeters didn’t agree with the autopilot setting.  Just as they were asking each other what was going on the aircraft crashed into the everglades.  Killing 101 of the 176 on board.

On June 1, 2009, Air France Flight 447 was en route from Rio de Janeiro to Paris.  This was a fly-by-wire Airbus A330 aircraft.  With side stick controllers (i.e., joysticks) instead of the traditional wheel and yoke controls.  The A330 had sophisticated automatic flight controls.  They practically flew the plane by themselves.  With pilots spending more of their time monitoring and inputting inputs to these systems than flying.  Flight 447 flew into some turbulence.  The autopilot disengaged.  The aircraft began to roll from the turbulence.  The pilot tried to null these out but over compensated.  At the same time he pitched the nose up abruptly, slowing the airplane and causing a stall warning as the excessive angle of attack slowed the plane from 274 knots to 52 knots.  The pilot got the rolling under control but due to the excessive angle of attack the plane was gaining a lot of altitude.  The pitot tube (a speed sensing device) began to ice up, reducing the size of the opening the air entered.  Changing the airflow into the tube.  Resulting in a speed indication that they were flying faster than they actually were.  The engines were running at 100% power but the nose was pitched up so much that the plane was losing speed and altitude.  There was no accurate air speed indication.  For pilot or autopilot.  The crew failed to follow appropriate procedures for problems with airspeed indication.  And did not understand how to recognize the approach of a stall.  Despite the high speed indicated the plane was actually stalling.   Which it did.  And fell from 38,000 feet in 3 and a half minutes.  Crashing into the ocean.  Killing all 228 on board.

It takes a lot to bring an airplane down from the sky.  And when it happens it is usually the last in a chain of events.  Where each individual event in the chain could not have brought the plane down.  But when taken together they can.  Most times pilots have a chance to save the aircraft.  Especially the stick and rudder pilots.  Who gained a lot of flying experience before the advanced autopilot systems of today.  And can feel what the airplane is doing through the touch of their hand on the yoke and through the seat of their pants.  They are tuned in to the engine noise and the environment around them.  Processing continuous sensations and sounds as well as studying their instruments and the airspace in front of them.  Because they flew the airplane.  Not the computers.  Allowing them to take immediate action instead of trying to figure out what was happening with the computers.  Losing precious time when additional seconds could trigger that last event in a chain of events that ends in the loss of the aircraft.  That’s why some of the best pilots come from this stick and rudder generation.  Such as Aloha Airlines Flight 243, American Airlines Flight 96 and United Airlines Flight 232.  Sometimes the event is so sudden or so catastrophic that there is nothing a pilot can do to save the aircraft.  Such as Japan Airlines Flight 123 and TWA Flight 800.  And sometimes pilots rely so much on automated systems that they let themselves get distracted from the business of flying.  Even the best stick and rudder pilots adjusting to new technology.  Such as Eastern Airlines Flight 401.  Or pilots brought up on the new technology.  Such as Air France Flight 447.  But these events are so rare that when a plane does fall out of the sky it is big news.  Because it rarely happens.  Planes have never been safer.  Which may now be the greatest danger in flying.  A false sense of security.  Which may allow a chain of events to end in a plane falling down from the sky.  As pilots rely more and more on computers to fly our airplanes they may step in too late to fix a problem.  Or not at all.  Trusting those computers more than their piloting skills.

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Carnegie, Rockefeller, Ford, Westinghouse, Boeing, Gates and Tariffs

Posted by PITHOCRATES - September 10th, 2013

History 101

Ford brought the Price of Cars down and Paid his Workers more without Tariff Protection

Andrew Carnegie grew a steel empire in the late 19th century.  With technological innovation.  He made the steel industry better.  Making steel better.  Less costly.  And more plentiful.  Carnegie’s steel built America’s skylines.  Allowing our buildings to reach the sky.  And Carnegie brought the price of steel down without tariff protection.

John D. Rockefeller saved the whales.  By making kerosene cheap and plentiful.  Replacing whale oil pretty much forever.  Then found a use for another refined petroleum product.  Something they once threw away.  Gasoline.  Which turned out to be a great automotive fuel.  It’s so great that we use it still today.  Rockefeller made gasoline so cheap and plentiful that he put the competition out of business.  He was making gasoline so cheap that his competition went to the government to break up Standard Oil.  So his competition didn’t have to sell at his low prices.  And Rockefeller made gasoline so inexpensive and so plentiful without tariff protection.

Henry Ford built cars on the first moving assembly line.  Greatly bringing the cost of the car down.  Auto factories have fixed costs that they recover in the price of the car.  The more cars a factory can make in a day allows them to distribute those fixed costs over more cars.  Bringing the cost of the car down.  Allowing Henry Ford to do the unprecedented and pay his workers $5 a day.  Allowing his workers to buy the cars they assembled.  And Ford brought the price of cars down and paid his workers more without tariff protection.

George Westinghouse decreased the Cost of Electric Power without Tariff Protection

George Westinghouse gave us AC power.  Thanks to his brilliant engineer.  Nikola Tesla.  Who battled his former employer, Thomas Edison, in the Current Wars.  Edison wanted to wire the country with his DC power.  Putting his DC generators throughout American cities.  While Westinghouse and Tesla wanted to build fewer plants and send their AC power over greater distances.  Greatly decreasing the cost of electric power.  Westinghouse won the Current Wars.  And Westinghouse did that without tariff protection.

After losing out on a military contract for a large military transport jet Boeing regrouped and took their failed design and converted it into a jet airliner.  The Boeing 747.  Which dominated long-haul routes.  Having the range to go almost anywhere without refueling.  And being able to pack so many people into a single airplane that the cost per person to fly was affordable to almost anyone that wanted to fly.  And Boeing did this without tariff protection.

Bill Gates became a billionaire thanks to his software.  Beginning with DOS.  Then Windows.  He dominated the PC operating system market.  And saw the potential of the Internet.  Bundling his browser program, Internet Explorer, with his operating system.  Giving it away for free.  Consumers loved it.  But his competition didn’t.  As they saw a fall in sales for their Internet browser programs.  With some of their past customers preferring to use the free Internet Explorer instead of buying another program.  Making IE the most popular Internet browser on the market.  And Gates did this without tariff protection.

Tariff Protection cost American Industries Years of Innovation and Cost Cutting Efficiencies

Carnegie Steel became U.S. Steel.  Which grew to be the nation’s largest steel company.  Carnegie had opposed unions to keep the cost of his steel down.  U.S. Steel had a contentious relationship with labor.  During the Great Depression U.S. Steel unionized.  But there was little love between labor and management.  There were a lot of strikes.  And a lot of costly union contracts.  Which raised the price of U.S. manufactured steel.  Opening the door for less costly foreign imports.  Which poured into the country.  Taking a lot of business away from domestic steel makers.  Making it more difficult to honor those costly union contracts.  Which led the U.S. steel producers to ask the government for tariff protection.  To raise the price of the imported steel so steel consumers would not have a less costly alternative.

During World War II FDR was printing so much money to pay for both the New Deal and the war the FDR administration was worried about inflation.  So they put ceilings on what employers could pay their employees.  With jobs paying the same it was difficult to attract the best employees.  Because you couldn’t offer more pay.  So General Motors started offering benefits.  Health care.  And pensions.  Agreeing to very generous union contracts.  Raising the price of cars.  Which wasn’t a problem until the imports hit our shores.  Then those union contracts became difficult to honor.  Which led the U.S. auto makers to ask the government for tariff protection.  To raise the price of those imported cars so Americans would not have a less costly alternative.

These two industries received their tariffs.  And other government protections.  Allowing them to continue with business as usual.  Even though business as usual no longer worked.  So while the foreign steel producers and auto makers advanced their industries to further increase quality and lower their costs the protected U.S. companies did not.  Because they didn’t have to.  For thanks to the government they didn’t have to please their customers.  As the government simply forced people to be their customers.  For awhile, at least.  The foreign products became better and better such that the tariff protection couldn’t make the higher quality imports costly enough to keep them less attractive than the inferior American goods.  With a lot of people even paying more for the better quality imports.  Losing years of innovation and cost cutting efficiencies due to their tariff protection these American industries that once dominated the world became shells of their former selves.  With General Motors and Chrysler having to ask the government for a bailout because of the health care and pension costs bankrupting them.  Something Carnegie, Rockefeller, Ford, Westinghouse, Boeing or Gates never had to ask.

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Air Transport vs. Rail Transport

Posted by PITHOCRATES - July 29th, 2013

Economics 101

Trains require an Enormous Amount of Infrastructure between Terminal Points whereas a Plane does Not

Trains and jets are big and expensive.  And take huge sums of money to move freight and passengers.  Each has their strength.  And each has their weakness.  Planes are great for transporting people.  While trains are best for moving heavy freight.  They both can and do transport both.  But pay a premium when they are not operating at their strength.

The big difference between these two modes of transportation is infrastructure.  Trains require an enormous amount of infrastructure between terminal points.  Whereas a plane doesn’t need anything between terminal points.  Because they fly in the air.  But because they fly in the air they need a lot of fuel to produce enough lift to break free from the earth’s gravity.  Trains, on the other hand, don’t have to battle gravity as much.  As they move across the ground on steel rails.  Which offer little resistance to steel wheels.  Allowing them to pull incredible weights cross country.  But to do that they need to build and maintain very expensive train tracks between point A and point B.

To illustrate the difference in costs each incurs moving both people and freight we’ll look at a hotshot freight train and a Boeing 747-8.  A hotshot freight gets the best motive power and hustles on the main lines across the country.  The Boeing 747-8 is the latest in the 747 family and includes both passenger and freighter versions.  The distance between Los Angeles (LA) and New York City (NYC) is approximately 2,800 miles.  So let’s look at the costs of each mode of transportation moving both people and freight between these two cities.

Railroads are so Efficient at moving Freight because One Locomotive can pull up to 5,000 Tons of Freight

There are many variables when it comes to the cost of building and maintaining railroad track.  So we’re going to guesstimate a lot of numbers.  And do a lot of number crunching.  An approximate number for the cost per mile of new track is $1.3 million.  That includes land, material and labor.  So the cost of the track between LA and NYC is $3.6 billion.  Assuming a 7-year depreciation schedule that comes to $1.4 million per day.  If it takes 3 days for a hotshot freight to travel from LA to NYC that’s $4.3 million for those three days.  Of course, main lines see a lot of traffic.  So let’s assume there are 8 trains a day for a total of 24 trains during that 3-day period.  This brings the depreciation expense for that trip from LA to NYC down to $178,082.

So that’s the capital cost of those train tracks between point A and point B.  Now the operating costs.  An approximate number for annual maintenance costs per mile of track is $300,000.  So the annual cost to maintain the track between LA and NYC is $840 million.  Crunching the numbers the rest of the way brings the maintenance cost for that 3-day trip to approximately $278,671.  Assuming a fuel consumption of 4 gallons per mile, a fuel cost of $3/gallon and a lashup of 3 locomotives the fuel cost for that 3-day trip is approximately $100,800.  Adding the capital cost, the maintenance expense and the fuel costs brings the total to $566,553.  With each locomotive being able to pull approximately 5,000 tons of freight for a total of 15,000 tons brings the cost per ton of freight shipped to $37.77.

Now let’s look at moving people by train.  People are a lot lighter than heavy freight.  So we can drop one locomotive in the lashup.  And burn about a gallon less per mile.  Bringing the fuel cost down from $100,800 to $50,400.  And the total cost to $516,153.  Assuming these locomotives pull 14 Amtrak Superliners (plus a dining car and a baggage car) that’s a total of 1,344 passengers (each Superliner has a 96 passenger maximum capacity).  Dividing the cost by the number of passengers gives us a cost of $384.04 per passenger.

Passenger Rail requires Massive Government Subsidies because of the Costs of Building and Maintaining Track

A Boeing 747-8 freighter can carry a maximum 147.9 tons of freight.  While consuming approximately 13.7 gallons of jet fuel per mile.  At 2,800 miles that trip from LA to NYC will consume about 38,403 gallons of jet fuel.  At $3/gallon that comes to a $115,210 total fuel cost.  Or $778.97 per ton.  Approximately 1,962% more than moving a ton of freight from LA to NYC by train.  Excluding the capital costs of locomotives, rolling stock, airplanes, terminal infrastructure/fees, etc.  Despite that massive cost of building and maintaining rail between point A and point B the massive tonnage a train can move compared to what a plane can carry makes the train the bargain when moving freight.  But it’s a different story when it comes to moving people.

The Boeing 747-8 carries approximately 467 people on a typical flight.  And burns approximately 6.84 gallons per mile.  Because people are a lot lighter than freight.  Crunching the numbers gives a cost per passenger of $123.11.  Approximately 212% less than what it costs a train to move a person.  Despite fuel costs being almost the same.  The difference is, of course, the additional $465,753 in costs for the track running between LA and NYC.  Which comes to $346.54 per passenger.  Or about 90% of the cost/passenger.  Which is why there are no private passenger railroads these days.  For if passenger rail isn’t heavily subsidized by the taxpayer the price of a ticket would be so great that no one would buy them.  Except the very rich train enthusiast.  Who is willing to pay 3 times the cost of flying and take about 12 times the time of flying.

There are private freight railroads.  Private passenger airlines.  And private air cargo companies.  Because they all can attract customers without government subsidies.  Passenger rail, on the other hand, can’t.  Because of the massive costs to build and maintain railroad tracks.  With high-speed rail being the most expensive track to build and maintain.  Making it the most cost inefficient way to move people.  Requiring massive government subsidies.  Either for the track infrastructure.  Or the electric power that powers high-speed rail.

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Kerosene, Jet Fuel, Lockheed Constellation, Boeing 707, Boeing 747-400, Newton’s Third Law of Motion, Turbojet and Fan Jet

Posted by PITHOCRATES - October 3rd, 2012

Technology 101

The only way to make Flying Available to the General Public is to put as many People as Possible on an Airplane

Refined petroleum products have made our lives better.  We have gasoline to drive wherever we want.  We have diesel fuel to transport things on ships and trains like petroleum oil, iron ore, coal, food, medicine, smartphones, coffee, tea, wine, scotch whisky, bourbon whiskey, beer, fresh fish, sushi, etc.  Pretty much everything we buy at a store or a restaurant got there on something powered by diesel fuel.  And sometimes kerosene.  If it must travel fast.  And if it does then it finds itself on a jet aircraft.

Today aviation has shrunk the world.  We can order a new smartphone sitting on a shelf in California and have it the next day in New York.  We can even travel to distant countries.  Some in the time of a typical working day.  Some a half a day or longer.  When but a 100 years earlier it took a couple of weeks to cross the Atlantic Ocean.  While 200 years ago it took a couple of months.  We can travel anywhere.  And get there quickly.  Thanks to the jumbo jet.  And not just the super-rich.  Pretty much anyone today can afford to buy a plane ticket to travel anywhere in the world.  And one thing makes this possible.  The jet engine.

Airplanes are expensive.  So are airports, air traffic control and jet fuel.  Airlines pay for all of these costs one passenger at a time.  Their largest cost is their fuel cost.  The longer the flight the greater the cost.  So the only way to make flying available to the general public is to put as many people as possible on an airplane.  Dividing the total flying cost by the number of passengers on the airplane.  This is why we fly on jumbo jets for these longer flights.  Because there are more people to split the total costs.  Lowering the cost per ticket.  Before the jet engine, though, it was a different story.

The Boeing 747-400 can take up to 660 Passengers some 7,260 Miles at a Speed of 567 MPH

One of the last intercontinental propeller-driven airplanes was the Lockheed Constellation.  A plane with four (4) Wright R-3350-DA3 Turbo Compound 18-cylinder supercharged radial engines putting out 3,250 horsepower each.  Which is a lot considering today’s typical 6-cyclinder automobile engine is lucky to get 300 horsepower.  No, the horsepower of one of these engines is about what one modern diesel-electric locomotive produces.  So these are big engines.  With a total power equal to about four locomotives lashed up.  Which is a lot of power.  And what does that power allow the Constellation do?  Not much by today’s standards.

In its day the Lockheed Constellation was a technological wonder.  It could take up to 109 passengers some 5,500 miles at a speed of 340 mph.  No bus or train could match this.  Not to mention it could fly over the water.  Then came the age of the jet.  The Boeing 707 being the first largely successful commercial jetliner.  Which could take up to 189 passengers some 6,160 miles at a speed of 607 mph.  That’s 73.4% more passengers, a 78.5% faster speed and a 14.1% longer range.  Which is an incredible improvement over the Constellation.  But nothing compared to the Boeing 747-400.  Which can take up to 660 passengers (506% more than the Constellation and 249% more than the 707) some 7,260 miles at a speed of 567 mph.

Now remember, fuel is the greatest cost of aviation.  So let’s assume that a intercontinental flight costs a total of $75,000 for each plane flying the same route.  Dividing that cost by the number of passengers you get a ticket price of approximately $688, $397 and $114 for the Constellation, the 707 and the 747-400, respectively.  So you can see the advantage of packing in as many passengers as possible into an airplane to lower the cost of flying.  Which is why the jumbo jets fly the longest routes that consume the most fuel.  And why we no longer fly propeller-driven aircraft except on short routes to airports with short runways.  These engines just don’t have the power to get a plane off the ground with enough people to reduce the cost of flying to a price most people could afford.  Only the jet engine has that kind of power.

The Fan Jet is basically a Turbojet with a Large Fan in front of the Compressor

Newton’s Third Law of Motion states that for every action there is an equal and opposite reaction.  Think of a balloon you just blew up and are holding closed.  If you release your hold air will exit the balloon in one direction.  And the balloon will move in the opposite direction.  This is how a jet engine moves an aircraft.  Hot exhaust gases exit the engine in one direction.  Pushing the jet engine in the opposite direction.  And because the jet engines move the plane moves.  With the force of the jet engines transferred via their connection points to the aircraft.  The greater the speed of the gas exiting the jet the faster it will push a plane forward.

The jet engine gets that power from the continuous cycle of the jet engine.  Air enters one end, gets compressed, enters a combustion chamber, mixes with fuel (kerosene), ignites, expands rapidly and exits the other end.  The hot (3,632 degree Fahrenheit) and expanding gases pass through and spin a turbine.  Then exit the engine.  The turbine is connected to the compressor at the front of the engine.  So the exhaust gases spin the compressor that sucks air into the engine.  As the air passes through the compressor it compresses and heats up.  Then it enters the combustion chamber and joins fuel that is injected and burned continuously.  Sort of like pouring gas on a burning fire.  Only enormous amounts of compressed air and kerosene are poured onto a burning fire.  As this air-fuel mixture burns it rapidly expands.  And exits the combustion chamber faster than the air entered it.  And shoots a hot stream of jet gas out the tail pipe.  Which produces the loud noise of these turbojets.  This fast jet of air cuts through the surrounding air.  Resulting in a shear effect.  Which the next generation of jet engines, the fan jet, greatly reduces.

The fan jet is basically a turbojet with one additional feature.  A large fan in front of the compressor.  These are the big engines you see on the jumbo jets.  They add another turbine inside the jet that spins the fan at the front of the engine.  Which feeds some air into the compressor of what is basically a turbojet.  But a lot of the air this fan sucks in bypasses the turbojet core.  And blows directly out the back of the fan at high speed.  In fact, this bypass air provides about 75% of the total thrust of the fan jet.  Acting more like a propeller than a jet.  And as an added benefit this bypass air surrounds the faster exhaust of the jet thereby lessening the shear effect.  Making these larger engines pretty quiet.  In fact a DC-9, an MD-80, a 707 or a 727 with standard turbojets are much louder than a 747 with 4 fan jets at full power.  They’re quieter.  And they can push a lot more people through the air at incredible speeds over great distances at a reasonable price per passenger than any other aircraft engine.

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Generator, Current, Voltage, Diesel Electric Locomotive, Traction Motors, Head-End Power, Jet, Refined Petroleum and Plug-in Hybrid

Posted by PITHOCRATES - June 6th, 2012

Technology 101

When the Engineer advances the Throttle to ‘Run 1’ there is a Surge of Current into the Traction Motors

Once when my father suffered a power outage at his home I helped him hook up his backup generator.  This was the first time he used it.  He had sized it to be large enough to run the air conditioner as Mom had health issues and didn’t breathe well in hot and humid weather.  This outage was in the middle of a hot, sweltering summer.  So they were eager to get the air conditioner running again.  Only one problem.  Although the generator was large enough to run the air conditioner, it was not large enough to start it.  The starting in-rush of current was too much for the generator.  The current surged and the voltage dropped as the generator was pushed beyond its operating limit.  Suffice it to say Mom suffered during that power outage.

Getting a diesel-electric locomotive moving is very similar.  The massive diesel engine turns a generator.  When the engineer advances the throttle to ‘Run 1’ (the first notch) there is a surge of current into the traction motors.  And a drop in voltage.  As the current moves through the rotor windings in the traction motors it creates an electrical field that fights with the stator electrical field.  Creating a tremendous amount of torque.  Which slowly begins to turn the wheels.  As the wheels begin to rotate less torque is required and the current decreases and voltage increases.  Then the engineer advances the throttle to ‘Run 2’ and the current to the traction motors increases again.  And the voltage falls again.  Until the train picks up more speed.  Then the current falls and the voltage rises.  And so on until the engineer advances the throttle all the way to ‘Run 8’ and the train is running at speed. 

The actual speed is controlled by the RPMs of the diesel engine and fuel flow to the cylinders. Which is what the engineer is doing by advancing the throttle.  In a passenger train there are additional power needs for the passenger cars.  Heating, cooling, lights, etc.  The locomotive typically provides this Head-End Power (HEP).  The General Electric Genesis Series I locomotive (the aerodynamic locomotive engines on the majority of Amtrak’s trains), for example, has a maximum of 800 kilowatts of HEP available.  But there is a tradeoff in traction power that moves the train towards its destination.  With a full HEP load a 4,250 horsepower rated engine can only produce 2,525 horsepower of traction power.  Or a decrease of about 41% in traction horsepower due to the heating, cooling, lighting, etc., requirements of the passenger cars.  But because passenger cars are so light they can still pull many of them with one engine.  Unlike their freight counterparts.  Where it can take a lashup of three engines or more to move a heavy freight train to its destination.  Without any HEP sapping traction horsepower.

There is so much Energy available in Refined Petroleum that we can carry Small Amounts that take us Great Distances

The largest cost of flying a passenger jet is jet fuel.  That’s why they make planes out of aluminum.  To make them light.  Airbus and Boeing are using ever more composite materials in their latest planes to reduce the weight further still.  New engine designs improve fuel economy.  Advances in engine design allow bigger and more powerful engines.  So 2 engines can do the work it took 4 engines to do a decade or more ago.  Fewer engines mean less weight.  And less fuel.  Making the plane lighter and more fuel efficient.  They measure all cargo and count people to determine the total weight of plane, cargo, passengers and fuel.  So the pilot can calculate the minimum amount of fuel to carry.  For the less fuel they carry the lighter the plane and the more fuel efficient it is.   During times of high fuel costs airlines charge extra for every extra pound you bring aboard.  To either dissuade you from bringing a lot of extra dead weight aboard.  Or to help pay the fuel cost for the extra weight when they can’t dissuade you.

It’s similar with cars.  To meet strict CAFE standards manufacturers have been aggressively trying to reduce the weight of their vehicles.  Using front-wheel drive on cars saved the excess weight of a drive shaft.  Unibody construction removed the heavy frame.  Aerodynamic designs reduced wind resistance.  Use of composite materials instead of metal reduced weight.  Shrinking the size of cars made them lighter.  Controlling the engine by a computer increased engine efficiencies and improved fuel economy.  Everywhere manufacturers can they have reduced the weight of cars and improved the efficiencies of the engine.  While still providing the creature comforts we enjoy in a car.  In particular heating and air conditioning.  All the while driving great distances on a weekend getaway to an amusement park.  Or a drive across the country on a summer vacation.  Or on a winter ski trip.

This is something trains, planes and automobiles share.  The ability to take you great distances in comfort.  And what makes this all possible?  One thing.  Refined petroleum.  There is so much energy available in refined petroleum that we can carry small amounts of it in our trains, planes and automobiles that will take us great distances.  Planes can fly halfway across the planet on one fill-up.  Trains can travel across numerous states on one fill-up.  A car can drive up to 6 hours or more doing 70 MPH on the interstate on one fill-up.  And keep you warm while doing it in the winter.  And cool in the summer.  For the engine cooling system transfers the wasted heat of the internal combustion engine to a heating core inside the passenger compartment to heat the car.  And another belt slung around an engine pulley drives an air conditioner compressor under the hood to cool the passenger compartment.  Thanks to that abundant energy in refined petroleum creating all the power under the hood we need.

The Opportunity Cost of the Plug-in Hybrid is giving up what the Car Originally gave us – Freedom 

And then there’s the plug-in hybrid car.  That shares some things in common with the train, plane and (gasoline-powered) automobile.  Only it doesn’t do anything as well.  Primarily because of the limited range of the battery.  Electric traction motors draw a lot of current.  But a battery’s storage capacity is limited.  Some batteries offer only about 20-30 miles of driving distance on a charge.  Which is great if you use a car for very, very short commutes.  But as few do manufacturers add a backup gasoline engine so the car can go almost as far as a gasoline-powered car.  It probably could go as far if it wasn’t for that heavy battery and generator it was dragging around with it.

This is but one of many tradeoffs required in a plug-in hybrid car.  Most of these cars are tiny to make them as light as possible.  For the lighter the car is the less current it takes to get it moving.  But adding a backup gasoline engine and generator only makes the car heavier.  Thus reducing its electric range.  Making it more like a conventional car for a trip longer than 20-30 miles.  Only one that gets a poorer fuel economy.  Because of the extra weight of the battery and generator.  Manufacturers have even addressed this problem by reducing the range of the car.  If people don’t drive more than 10 miles on a typical trip they don’t need such a large battery.  Which is ideal if you use your car to go no further than you normally walk.  A smaller battery means less weight due to the lesser storage capacity required to travel that lesser range.  Another tradeoff is the heating and cooling of the car.  Without a gasoline engine on all of the time these cars have to use electric heat.  And an electric motor to drive the air conditioner compressor.  (Some heating and cooling systems will operate when the car is plugged in to conserve battery charge for the initial climate adjustment).  So in the heat of summer and the cold of winter you can scratch off another 20% of your electric range (bringing that 20 miles down to 16 miles).  Not as bad as on a passenger locomotive.  But with its large tanks of diesel fuel that train can still take you across the country.

The opportunity cost of the plug-in hybrid is giving up what the car originally gave us.  Freedom.  To get out on the open road just to see where it would take us.  For if you drive a long commute or like to take long trips your hybrid is just going to be using the backup gasoline engine for most of that driving.  While dragging around a lot of excess weight.  To make up for some lost fuel economy some manufacturers use a gasoline engine with high compression.  Unfortunately, high compression engines require the more expensive premium (higher octane) gasoline.  Which costs more at the pump.  There eventually comes the point we should ask ourselves why bother?  Wouldn’t life and driving be so much simpler with a gasoline-powered car?  Get fuel economy with a range of over 300 miles?  Guess it all depends on what’s more important.  Being sensible.  Or showing others that you’re saving the planet.

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There Were Planes and There Were People

Posted by PITHOCRATES - September 12th, 2010

Yesterday was the anniversary of 9/11.  Today is the anniversary of the start of the conspiracy theories.

There were those who were adamant that it was an inside job.  That George W. Bush did it.  They said he was the brilliant mastermind behind the attacks.  When they weren’t calling him the incompetent in chief.  They pointed to the Pentagon attack.  An obvious missile attack.  There was no way a big plane like Boeing 757 could thread its way down to a streetlight-top altitude and hit the side of that building.  Maybe a cruise missile could, but not a commercial jet.  All right.  Let’s accept that theory.  Now answer me this.  Where is the plane?  Where are the passengers and crew?  Where are they today?

THE MIGHTY ARMS OF ATLAS

The engineers designed the Twin Towers to withstand the impact of an airplane.  To make it safe like the Empire State Building.  For when a plane struck the Empire State Building, it didn’t collapse.  But the Twin Towers did.  Proof that the Bush administration purposely blew up the Twin Towers.  And those commercial jetliners that hit the towers that day?  That was just a coincidence.  Or a clever ruse.  Perhaps military drones sent in to allay suspicion.  Or that Bush used unwitting terrorists as convenient patsies for his devilish schemes.  Just something that an evil genius would do.

The plane that crashed into the Empire State Building was a World War II medium bomber (B-25) with a cruising speed of about 230 mph.  The B-25 had a maximum speed of about 275 mph and had a range of about 1,300 miles.  It weighed just under 20,000 pounds empty.  It carried approximately 670 gallons of fuel when fully fueled.   The Boeing 767, on the other hand, has the following stats:  typical cruising speed: 530 mph; maximum takeoff weight: 450,000 pounds; maximum range: 5,625 nautical miles; maximum fuel capacity: 23,980 gallons.

The B-25 was a gorgeous, fast and lethal plane.  For its time.  But it pales in comparison to the 767.  The weight and speed of a 767 hitting a building could not be anything but cataclysmic.  But the Twin Towers withstood those impacts.  They absorbed tremendous amounts of kinetic energy.  Far more than the designers ever envisioned.  And yet the mighty arms of Atlas still reached skyward.  But that kinetic energy did its damage.  It compromised the fire proofing on the structural steel.  And there was all that fuel.  And fire.  A scenario no designer ever contemplated.

The Twin Towers had an ingenious open-floor plan.  Instead of having big columns in the office spaces, the sides of the building carried the load.  The floors were ‘hung’ from this structural steel.  The floors provided the rigidity of the towers while the exterior walls carried the weight.  With the fireproofing compromised, though, the steel spanning the floors heated up in that inferno.  It began to soften.  And sag.  This compromised the structural integrity.  The steel members could move.  Attachment points strained.  And failed.  A floor collapsed.  This increased instability.  More movement.  More stress.  More failures.  More floors collapsed.  One on top of another.  And then walls came tumbling down.

It was all that jet fuel.  It could sustain a fire to burn long enough and hot enough to soften structural steel (which is why structural steel is fireproofed).  That’s what brought the Twin Towers down.  Not George W. Bush.

THEY FOUGHT BACK

Of course, there’s not much the conspirators can say about the 4th plane.  Because of cell phones.  After the hijacking, passengers talked to family/others.  They learned that hijacked commercial jetliners attacked the Twin Towers and the Pentagon.  The passengers and crew on this hijacked jetliner knew what was going to happen.  They were going to die.  So they became the first to go on the offensive in the War on Terror.  They won the first skirmish in this new war.  A battle they entered likely knowing they would not survive.  But they swallowed their fear.  And acted.  Ordinary people doing extraordinary things.  God rest their souls.

There are a lot of conspiracy theories out there.  What you don’t hear a lot of is conspiracy motives.  I mean, if George W. Bush did this, why?  So he could have a successful war?  Like LBJ?  Did he also plan and execute the first World Trade Center bombing?  The Tanzanian Embassy bombing?  The Kenyan Embassy bombing?  The Khobar Towers bombing?  The USS Cole attack?  Did he create this anti-American sentiment as a clever ruse so one day he could become president and go to war?  This incompetent in chief? 

KNOW YOUR ENEMIES

Or can it be that America has real enemies?  People who resent and envy our life of plenty and freedom?  People in closed societies.  With an illiterate populace.  Who only know what their leaders tell them.  And their leaders lie.  The Soviet Union was such a society (well, a similar society, for they were literate.  But they only read propaganda so the end result was the same).  When a Soviet spy saw how it really was in the decadent West, he or she said screw this and defected.

If we’re speaking of motives, we should be asking what our enemies’ motives are.  For if we do, we don’t have to come up with any wild-ass conspiracy theories.  With them, if it walks, acts and quacks like a duck, it’s a duck.  They hate us.  They want to kill us.  So they try to kill us.  Whenever they get the chance.  It’s pretty straightforward.  Why, even George W. Bush could see this.  And that’s why the bad guys feared him.  He not only dug in his heels, he fought back.  With grim determination.  Unlike his predecessor.  Or his successor.

www.PITHOCRATES.com

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