The Doppler Effect and Malaysian Flight 370

Posted by PITHOCRATES - March 26th, 2014

Technology 101

A Swan Pushes Waves Together in front of it and Pulls Waves Apart behind it as it Paddles across Water

Throw a stone in the water and what do you see?  Little circular ripples in the water moving away from and centered on where the stone broke the surface of the water.  These are waves.  Energy.  They are more intense the closer they are to the point of disturbance.  And become less intense the further they are from the point of disturbance.  So you’ll see larger circular ripples in the water closer to where the stone hit the water.  And smaller circular ripples at increasing radii from the point of impact.

You’ll see these little circular waves, too, when something else disturbs the surface of the water.  Like a swan.  Or a duck.  As they paddle their feet they move forward in the water.  Pushing the water out ahead them.  If you look closely you’ll see ripples bunched up in front of them.  And ripples spaced further apart behind them.  This is because of their movement towards the previous ripple.

These waves ripple through the water at the same speed (assuming the swan or duck is paddling at a constant speed).  So each ripple will travel the same distance at the same speed from the paddling bird.  But as the bird moves forward each subsequent wave in that direction is starting its journey at a point further along in that direction.  So one wave may have gotten to a point (let’s call it Point A) in the water 3 inches ahead of where the bird created it.  Since creating that wave the bird continued to paddle.  And created another wave.  This one created only 2 inches from Point A.  And then the bird created another wave at only 1 inch from Point A.  So subsequent waves are ‘catching up’ to previous waves.  Thus bunching the waves up in front of the bird.  While the bird is pushing these waves closer together the bird is traveling away from the waves behind it.  Stretching those waves further apart from each other.

A Guitar makes Sound by Vibrating the Soundboard in the Body of the Guitar

If you’ve ever played a guitar or watched someone play the guitar you’ve probably noticed how the sound changes depending on where the player fingers the string on the fingerboard (or fretboard).  If the player presses down on the string closer to the body of the guitar the note sounds higher.  If the player presses down on the string further away from the body of the guitar the note sounds lower.  Why?  Frequency.

A guitar makes sound by vibrating the soundboard in the body of the guitar.  The faster it vibrates the higher pitch the sound.  The slower it vibrates the lower pitch the sound.  The string vibrates back and forth a number of times each second.  The more it moves back and forth in one second the higher the frequency and the higher the pitch.  The fewer times it does the lower the frequency and the lower the pitch.  Thinner strings vibrate faster than thicker strings.  Shorter strings vibrate faster than longer strings.  So a typical guitar has 6 strings of various thickness stretched from the soundboard across the fingerboard.

The vibrating soundboard creates sound waves that move through the air.  Similar to a rock breaking the surface of the water.  As a guitar player fingers different notes on the fingerboard the soundboard vibrates at different frequencies.  Making music.  If you’re attending a small concert where a soloist is playing, say, Spanish Dance No. 2: Oriental by Enrique Granados you would hear the same beautiful music wherever you were sitting in the room.  The sound waves would be radiating throughout the room like the ripples created when a rock breaks the surface of the water.  However, if the soloist was moving like a swan through the water it would be a different story.

Using the Doppler Effect they determined Malaysian Airlines Flight 370 traveled the Southern Route

Ever listen to the sounds of cars and trucks traveling down a highway?  Maybe while visiting your aunt and uncle who live on a highway out in the country?  Did you notice that they had a higher-pitched sound when they approached you than when after they had passed you by?  The next time something noisy passes you by listen.  Especially if they’re blowing their horn.  It’ll go from a higher-pitched sound to a lower-pitched sound just as it passes you.  Why?  Think of the waves a swan makes gliding through the water.  Bunching waves closer together in front of it.  And stretching them further apart behind it.  The same thing happens with sound waves.  Austrian physicist Christian Doppler noted this in 1842.  Something we now call the Doppler Effect.

If a train is travelling down the track while blowing its horn it sounds the same aboard the train from the moment the engineer starts blowing it until he or she stops.  Just as the sound of a soloist playing Spanish Dance No. 2: Oriental sounds the same wherever you are in the room.  Because the distance between the source of the sound and the listener of the sound does not change.  But if you were standing stationary near the railroad track as the train traveled past you the frequency of the horn changes.  Because as it is approaching you it is pushing sound waves closer together.  Creating a higher frequency (or a higher-pitched sound).  As the train passes it is stretching those sound waves further apart.  Creating a lower frequency (or a lower-pitched sound).  This is the Doppler Effect.

When Malaysian Airlines Flight 370 shut off its transponder and ACARS (Aircraft Communications Addressing and Reporting System) stopped broadcasting the plane vanished.  But a satellite communicating with the airplane still ‘pinged’ the aircraft every hour of its remaining flight time.  And electronic handshake.  The satellite says, “Are you still there?”  And the plane responds, “Yes I am.”  No data was transmitted.  Only a sent and received signal.  Just a pulse of a constant frequency.  A ping.  But from those pings they could measure the time it took to send and receive those pings.  Which they could calculate distances between the satellite and the plane from.  Giving us the northern and southern possible routes as it traveled in an arc around the satellite.  But which way it went on that arc was a mystery.  Until they analyzed the frequencies of those pings.  And they detected a slight change in the frequencies.  Using the Doppler Effect they determined which side of the plane was bunching up the sound waves and what side of it was stretching them out.  And concluded the plane was traveling on the southern route.  Which is why all search efforts are now in the south Indian Ocean southeast from Australia.  Because, according to Christian Doppler, that’s the direction the plane flew.

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On the Flightdeck during Aviation Disasters

Posted by PITHOCRATES - March 19th, 2014

Technology 101

USAir Flight 427 on Approach to Pittsburgh flew through Wake Vortex and Lost Control

Malaysian Airlines Flight 370 search is still ongoing.  We’re seemingly no closer to understanding what happened than before.  There has been a lot of speculation.  And rebuttals to that speculation.  With many people saying things like why didn’t the crew radio?  Why didn’t they report a problem?  While others are saying that it is proof for their speculative theory.  That they were either under duress, had no time or were in on it and, therefore, went silent.  So what is it like on the flightdeck when something happens to an aircraft?  Well, because of past CVR (cockpit voice recorder) transcripts from previous accidents, we can get an idea.

On September 8, 1994, USAir Flight 427 flew into the wake vortex (little tornados trailing from a large plane’s wingtip) of a Delta Airlines Boeing 727 ahead of it.  This sideways tornado disrupted the airflow over the control surfaces of the USAir 737.  Disrupting it from level flight, causing it to roll left.  The autopilot tried to correct the roll as the 737 passed through the wake vortex core.  Causing more disruption of the airflow over the control surfaces.  The first officer then tried to stabilize the plane.  Control of the aircraft continued to deteriorate.  We pick up the CVR transcript just before this event (see 8 September 1994 – USAir 427).  CAUTION: The following recounts the final moments of Flight 427 and some may find it disturbing.

CAM-1 = Captain
CAM-2 = First Officer
CAM-3 = Cockpit Area Mike (cabin sounds and flight attendants)
RDO-1 = Radio Communications (Captain)
APP: Pittsburgh Approach

APP: USAir 427, turn left heading one zero zero. Traffic will be one to two o’clock, six miles, northbound Jetstream climbing out of thirty-three for five thousand.
RDO-1: We’re looking for the traffic, turning to one zero zero, USAir 427.
CAM-3: [Sound in engines increasing rpms]
CAM-2: Oh, yeah. I see the Jetstream.
CAM-1: Sheez…
CAM-2: zuh?
CAM-3: [Sound of thump; sound like ‘clickety-click’; again the thumping sound, but quieter than before]
CAM-1: Whoa … hang on.
CAM-3: [Sound of increasing rpms in engines; sound of clickety-click; sound of trim wheel turning at autopilot trim speed; sound similar to pilot grunting; sound of wailing horn similar to autopilot disconnect warning]
CAM-1: Hang on.
CAM-2: Oh, Shit.
CAM-1: Hang on. What the hell is this?
CAM-3: [Sound of stick shaker; sound of altitude alert]
CAM-3: Traffic. Traffic.
CAM-1: What the…
CAM-2: Oh…
CAM-1: Oh God, Oh God…
APP: USAir…
RDO-1: 427, emergency!
CAM-2: [Sound of scream]
CAM-1: Pull…
CAM-2: Oh…
CAM-1: Pull… pull…
CAM-2: God…
CAM-1: [Sound of screaming]
CAM-2: No… END OF TAPE.

At 19:03:01 in the flight there was a full left rudder deflection.  The plane yawed (twisted like a weathervane) to the left.  A second later it rolled 30 degrees left.  This caused the aircraft to pitch down.  Where it continued to roll.  The plane rolled upside down and pitched further nose-down.  The pilots never recovered.  The plane flew nearly straight into the ground at 261kts.  The crash investigated focused on the rudder.  Boeing redesigned it.  Pilots since have received more training on rudder inputs.  And flight data recorders now record additional rudder data.  This incident shows how fast a plane can go from normal flight to a crash.  The captain had time to radio one warning.  But within seconds from the beginning of the event the plane crashed.  Illustrating how little time pilots have to identify problems and correct them.

An In-Flight Deployment of a Thrust Reverser breaks up Lauda Air Flight 004

A plane wants to fly.  It is inherently stable.  As long as enough air flows over its wings.  Jet engines provide thrust that push an airplane’s wings through the air.  The curved surfaces of the wings interacting with the air passing over it creates lift.  As long as a plane’s jet engines push the wing through the air a plane will fly.  On May 26, 1991, something happened to Lauda Air Flight 004 to disrupt the smooth flow of air over the Boeing 767’s wings.  Something that isn’t supposed to happen during flight.  But only when a plane lands.  Reverse thrust.  As a plane lands the pilot reverses the thrust on the jet engines to slow the airplane.  Unfortunately for Flight 004, one of its jet engines deployed its thrust reverser while the plane was at about 31,000 feet.  We pick up the CVR transcript just as they receive a warning indication that the reverse thruster could deploy (see 26 May 1991 – Lauda 004).  CAUTION: The following recounts the final moments of Flight 004 and some may find it disturbing.

23.21:21 – [Warning light indicated]

23.21:21 FO: Shit.

23.21:24 CA: That keeps, that’s come on.

23.22:28 FO: So we passed transition altitude one-zero-one-three

23.22:30 CA: OK.

23.23:57 CA: What’s it say in there about that, just ah…

23.24:00 FO: (reading from quick reference handbook) Additional system failures may cause in-flight deployment. Expect normal reverse operation after landing.

23.24:11 CA: OK.

23.24:12 CA: Just, ah, let’s see.

23.24:36 CA: OK.

23.25:19 FO: Shall I ask the ground staff?

23.25:22 CA: What’s that?

23.25:23 FO: Shall I ask the technical men?

23.25:26 CA: Ah, you can tell ’em it, just it’s, it’s, it’s, just ah, no, ah, it’s probably ah wa… ah moisture or something ’cause it’s not just, oh, it’s coming on and off.

23.25:39 FO: Yeah.

23.25:40 CA: But, ah, you know it’s a … it doesn’t really, it’s just an advisory thing, I don’t ah …

23.25:55 CA: Could be some moisture in there or somethin’.

23.26:03 FO: Think you need a little bit of rudder trim to the left.

23.26:06 CA: What’s that?

23.26:08 FO: You need a little bit of rudder trim to the left.

23.26:10 CA: OK.

23.26:12 CA: OK.

23.26:50 FO: (starts adding up figures in German)

23.30:09 FO: (stops adding figures)

23.30:37 FO: Ah, reverser’s deployed.

23.30:39 – [sound of snap]

23.30:41 CA: Jesus Christ!

23.30:44 – [sound of four caution tones]

23.30:47 – [sound of siren warning starts]

23.30:48 – [sound of siren warning stops]

23.30:52 – [sound of siren warning starts and continues until the recording ends]

23.30:53 CA: Here, wait a minute!

23.30:58 CA: Damn it!

23.31:05 – [sound of bang]

[End of Recording]

The 767 Emergency/Malfunction Checklist stated that upon receiving the warning indicator ADDITIONAL system faults MAY cause an in-flight deployment of the thrust reverser.  But that one warning indication was NOT expected to cause any problem with the thrust reversers in stopping the plane after landing.  At that point it was not an emergency.  So they radioed no emergency.  About 10 minutes later the thrust reverser on the left engine deployed in flight.  When it did the left engine pulled the left wing back as the right engine pushed the right wing forward.  Disrupting the airflow over the left wing.  Causing it to stall.  And the twisting force around the yaw axis created such great stresses on the airframe that the aircraft broke up in the air.  The event happened so fast from thrust reverser deployment to the crash (less than 30 seconds) the crew had no time to radio an emergency before crashing.

Fire in the Cargo Hold brought down ValuJet Flight 592

One of the most dangerous things in aviation is fire.  Fire can fill the plane with smoke.  It can incapacitate the crew.  It can burn through electric wiring.  It can burn through control cables.  And it can burn through structural components.  A plane flying at altitude must land immediately on the detection of fire/smoke.  Because they can’t pull over and get out of the plane.  They have to get the plane on the ground.  And the longer it takes to do that the more damage the fire can do.  On May 11, 1996, ValuJet Flight 592 took off from Miami International Airport.  Shortly into the flight they detected smoke inside the McDonnell Douglas DC-9.  We pick up the CVR transcript just before they detected fire aboard (see 11 May 1996 – ValuJet 591).  CAUTION: The following recounts the final moments of Flight 592 and some may find it disturbing.

CAM — Cockpit area microphone voice or sound source
RDO — Radio transmissions from Critter 592
ALL — Sound source heard on all channels
INT — Transmissions over aircraft interphone system
Tower — Radio transmission from Miami tower or approach
UNK — Radio transmission received from unidentified source
PA — Transmission made over aircraft public address system
-1 — Voice identified as Pilot-in-Command (PIC)
-2 — Voice identified as Co-Pilot
-3 — Voice identified as senior female flight attendant
-? — Voice unidentified
* — Unintelligible word
@ — Non pertinent word
# — Expletive
% — Break in continuity
( ) — Questionable insertion
[ ] — Editorial insertion
… — Pause

14:09:36 PA-2 flight attendants, departure check please.

14:09:44 CAM-1 we’re *** turbulence

14:09:02 CAM [sound of click]

14:10:03 CAM [sound of chirp heard on cockpit area microphone channel with simultaneous beep on public address/interphone channel]

14:10:07 CAM-1 what was that?

14:10:08 CAM-2 I don’t know.

14:10:12 CAM-1 *** (’bout to lose a bus?)

14:10:15 CAM-1 we got some electrical problem.

14:10:17 CAM-2 yeah.

14:10:18 CAM-2 that battery charger’s kickin’ in. ooh, we gotta.

14:10:20 CAM-1 we’re losing everything.

14:10:21 Tower Critter five-nine-two, contact Miami center on one-thirty-two-forty-five, so long.

14:10:22 CAM-1 we need, we need to go back to Miami.

14:10:23 CAM [sounds of shouting from passenger cabin]

14:10:25 CAM-? fire, fire, fire, fire [from female voices in cabin]

14:10:27 CAM-? we’re on fire, we’re on fire. [from male voice]

14:10:28 CAM [sound of tone similar to landing gear warning horn for three seconds]

14:10:29 Tower Critter five-ninety-two contact Miami center, one-thirty-two-forty-five.

14:10:30 CAM-1 ** to Miami.

14:10:32 RDO-2 Uh, five-ninety-two needs immediate return to Miami.

14:10:35 Tower Critter five-ninety-two, uh, roger, turn left heading two-seven-zero.  Descend and maintain seven-thousand.

14:10:36 CAM [sounds of shouting from passenger cabin subsides]

14:10:39 RDO-2 Two-seven-zero, seven-thousand, five-ninety-two.

14:10:41 Tower What kind of problem are you havin’?

14:10:42 CAM [sound of horn]

14:10:44 CAM-1 fire

14:10:46 RDO-2 Uh, smoke in the cockp … smoke in the cabin.

14:10:47 Tower Roger.

14:10:49 CAM-1 what altitude?

14:10:49 CAM-2 seven thousand.

14:10:52 CAM [sound similar to cockpit door moving]

14:10:57 CAM [sound of six chimes similar to cabin service interphone]

14:10:58 CAM-3 OK, we need oxygen, we can’t get oxygen back here.

14:11:00 INT [sound similar to microphone being keyed only on Interphone channel]

14:11:02 CAM-3 *ba*, is there a way we could test them? [sound of clearing her voice]

14:11:07 Tower Critter five-ninety-two, when able to turn left heading two-five-zero.  Descend and maintain five-thousand.

14:11:08 CAM [sound of chimes similar to cabin service interphone]

14:11:10 CAM [sounds of shouting from passenger cabin]

14:11:11 RDO-2 Two-five-zero seven-thousand.

14:11:12 CAM-3 completely on fire.

14:11:14 CAM [sounds of shouting from passenger cabin subsides]

14:11:19 CAM-2 outta nine.

14:11:19 CAM [sound of intermittant horn]

14:11:21 CAM [sound similar to loud rushing air]

14:11:38 CAM-2 Critter five-ninety-two, we need the, uh, closest airport available …

14:11:42 Tower Critter five-ninety-two, they’re going to be standing by for you. You can plan runway one two to dolpin now.

14:11:45 one minute and twelve second interruption in CVR recording]

14:11:46 RDO-? Need radar vectors.

14:11:49 Tower critter five ninety two turn left heading one four zero 14:11:52

RDO-? one four zero

14:12:57 CAM [sound of tone similar to power interruption to CVR]

14:12:57 CAM [sound similar to loud rushing air]

14:12:57 ALL [sound of repeating tones similar to CVR self test signal start and continue]

14:12:58 Tower critter five ninety two contact miami approach on corrections no you you just keep my frequency

14:13:11 CAM [interruption of unknown duration in CVR recording]

14:13:15 CAM [sounds of repeating tones similar to recorder self-test signal starts and continues, rushing air.]

14:13:18 Tower critter five ninety two you can uh turn left heading one zero zero and join the runway one two localizer at miami

14:13:25: End of CVR recording.

14:13:27 Tower critter five ninety two descend and maintain three thousand

14:13:43 Tower critter five ninety two opa locka airports aout ah twelve o’clock at fifteen miles

[End of Recording]

The cargo hold of this DC-9 was airtight.  This was its fire protection.  Because any fire would quickly consume any oxygen in the hold and burn itself out.  But also loaded in Flight 592’s hold were some oxygen generators.  The things that produce oxygen for passengers to breathe through masks that fall down during a loss of pressurization.  These produce oxygen through a chemical reaction that produces an enormous amount of heat.  These were hazardous equipment that were forbidden to be transported on the DC-9.  Some confusion in labeling led some to believe they were ’empty’ canisters when they were actually ‘expired’.  The crash investigation concluded that one of these were jostled on the ground and activated.  It produced an oxygen rich environment in the cargo hold.  And enough heat to start a smoldering fire.  Which soon turned into a raging inferno that burned through the cabin floor.  And through the flightdeck floor.  Either burning through all flight controls.  Or incapacitating the crew.  Sending the plane into a nose dive into the everglades in less than 4 minutes from the first sign of trouble.

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Malaysian Airlines Flight 370

Posted by PITHOCRATES - March 16th, 2014

Week in Review

There are a lot of airplanes in the air at any given time.  And, remarkably, over 99% of those planes reach their destinations safely.  So when one doesn’t it’s big news.  Such as Malaysian Airlines Flight 370.  A plane that has been missing since March 8, 2014.  Ten days as of this writing.  And still no one knows what happened.  There’s been a lot of speculation.  From pilot suicide to fire to electrical failure to catastrophic mechanical failure to a high jacking to piracy.  Some have even suggested that it may have been a trial run by terrorists to test a new terror plot.  To see the problems they may encounter.  And to see what the response would be.  If it wasn’t it might as well had been.  As all the speculators have given a wealth of information that terrorists might have gained had it been a trial run.

So what do we know?  Concretely?  The plane and the people aboard are missing.  Which is the only absolute we know.  Now what plausible assumptions can we make?  The plane crashed and we haven’t found it yet.  Or the plane was stolen.  For some future use.  If it crashed it is imperative to find it should there be an unknown issue with the Boeing 777.  An incredibly safe airliner to date.  And very popular with the airlines for their long-haul routes.  So if there is an unknown issue we need to know because there are so many of these flying.

Perhaps the more disturbing assumption is that it was stolen.  Because it is an intercontinental jetliner.  North Korea has missiles that can reach the United States.  Saddam Hussein had scud missiles that could reach Israel.  Iran has a nuclear program.  But may not have long-range missile technology.  A 777 provides long-range capability.  And if it was stolen it would be hard to blame any state for what may happen if that plane was used for some nefarious purpose.  As there would be no flight plan filed tracing it back to a departing airport.  Which is even a greater incentive to find it.  As a lot of people are talking about this possibility one would assume that great attention is being placed on runways long enough for a refueled 777 to take off from.  Which would be longer than one needed to land a 777 low on fuel.  And one could also assume that airborne radar is being used to try and catch anyone trying to fly at night below radar coverage.  Giving ample warning to scramble fighter jets to intercept the threat.  And shooting it down if necessary.  So even if it turns out that the airplane was stolen it would be very difficult to use that airplane for nefarious purposes.  But not impossible.

There would be a lot less speculation had that transponder remained turned on.  For if we can ‘see’ the airplane we know where it is.  A rather simple device that tells air traffic control everything they need to know about an airplane.  Which is important considering how many airplanes are in the sky at any one time.  Just to get an idea of how many you can watch a visualization of all air traffic over European airspace (see Watch an Entire Day of Air Traffic in One Astonishing Visualization by Kyle VanHemert posted 3/14/2014 on Wired).  So perhaps ‘hardening’ the transponder is the first thing we should be doing.  Something that can probably be done for little cost.  Say adding a rechargeable battery to the transponder that is only accessible from outside the aircraft.  So it is inaccessible during flight.  If the transponder is switched off and it transfers to battery it could broadcast the high jacking code.  While providing the plane’s location.  If the plane has a catastrophic breakup in flight the transponder could be in a hardened shell that keeps broadcasting during and after this event on battery power.  It may add some weight.  And some cost.  But if it can provide an aircraft’s location after an event it may prevent some of the uncertainty in future events like there is with Malaysian Airlines Flight 370.

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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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Autopilots and Lawyers take Flying Time away from Pilots, Increase Stalls

Posted by PITHOCRATES - November 3rd, 2013

Week in Review

Flying has never been safer.  Air craft incidents make the news because they are so rare.  Such as two planes clipping wings on the tarmac.  And any crash is on the news 24 hours a day.  Because they are so rare that statistically they just don’t happen.  But as rare as they are they still happen.  And planes fall out of the sky (see Crash investigator urges stall training for pilots by Bart Jansen posted 10/30/2013 on USA Today).

A federal crash investigator urged a conference of aviation safety officials Tuesday to better train pilots to avoid stubborn problems such as stalls.

Earl Weener, a member of the National Transportation Safety Board, recalled four separate fatal crashes over the past two decades that he said involved stalls, with pilots basically pulling the plane’s nose up too much until the aircraft fell to the ground.

“The question in my mind is why did the crew continue to pull back on the elevator all the way to the ground,” Weener told about 300 people attending the Flight Safety Foundation’s International Aviation Safety Summit, rather than leveling off to regain power and speed.

Lack of training is feared to be one culprit…

A NASA study of voluntary reporting by pilots found stalls 28% of the time while cruising at high altitude, Weener said. And an airline database study by the International Air Transport Association found 27% of stalls occurred while cruising, he said.

But a survey found only 26% of airlines trained for high-altitude stalls – even though 71% of stalls occur when the autopilot is typically engaged, Weener said.

Lack of training?  With 71% of stalls happening while flying on autopilot try lack of flying.

Most accidents today are pilot error.  Is it because we have bad pilots?  No.  It’s because we’re not letting them fly.  In the risk-averse world we live in today we try to avoid all risk.  We have autopilot systems that are so sophisticated that they can fly a plane without a pilot aboard.  In our litigious society airlines feel machines will make fewer mistakes than people.  So they have the machines fly the plane most of the time.  While pilots monitor the systems.  Entering set-points into the flight computers.  While the computers fly the plane.  And when there is a problem pilots try to get the flight computers working.  Instead of taking the controls themselves.

Before pilots turned flying over to the machines they flew the planes.  They felt the planes.  They listened to the planes.  And flew by the seat of their pants.  If there was an odd vibration they felt it.  If there was an engine problem they heard it.  And if the plane stalled they felt it in the pit of their stomach.  And instinctively pushed forward on the column and applied full power. 

Today, because of lawyers, airlines want pilots to fix the autopilot.  Not take the controls.  So the machines can start flying again as soon as possible.  As they feel they are less likely to make a mistake than a pilot doing some real flying.  Unfortunately, a machine will only fly as well as a human can tell it to fly.  By entering those set-points.  And if the human makes a mistake at data entry the computer will assume that the human didn’t make a mistake.  And follow those instructions exactly.  Even if the plane flies into the ground.  Or stalls and falls out of the sky.

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Aircraft De-Icing Systems

Posted by PITHOCRATES - October 23rd, 2013

Technology 101

A build-up of Ice on Airfoils causes a Reduction of Lift and a Loss of Stability

In the classic movie Airport (1970) after the guy pulled the trigger on his briefcase bomb the plane suffered a massive decompression.  When Dean Martin got back to the cockpit he told the flight engineer to give them all the heat they had.  Because it’s very cold flying above 10,000 feet without pressurization.  That’s why World War II flight crews wore a lot of heavy clothing and thick mittens in their bombers.  As well as oxygen masks as the air was too thin to breathe.  The B-17 even had open windows for the waste gunners.  Making it very cold inside the plane.  Because the air is very, very cold at altitude.

There is another problem at altitude.  Because of these very frigid temperatures.  Water droplets in the air will freeze to any surface they come into contact with.  They can reduce engine power for both propeller and jet engines.  They can freeze on ports used for instrumentation and give inaccurate readings of vital aircraft data (such as engine pressure ratio, aircraft speed, etc.).  And they can freeze on airfoils (wings, rudder, tail fin, etc.).  Disturbing the airflow on these surfaces.  Causing a reduction of lift and a loss of stability.

Ice and airplanes are two things that don’t go together.  As ice forms on a wing it disturbs the airflow over the surface of the wing.  Increasing drag.  And reducing lift.  Causing the plane to lose speed.  And altitude.  If the ice continues to form on the wing eventually it will stall the wing.  And if the wing stalls (i.e., produces no lift) the plane will simply fall out of the sky.  In the early days of aviation pilots were highly skilled in flying their planes where there were no icing conditions.  Flying over, under or around masses of air containing water droplets in subfreezing temperatures.  Today we have anti-icing systems.

The most common Anti-Icing System on Commercial Jets is a Bleed Air System

One of the most common anti-icing systems on turboprop aircraft is the use of inflatable boots over the leading edge of the wing.  Basically a rubber surface that they can pump air into.  When there is no ice on the wing the boot lies flat on the leading edge without interrupting the airflow.  When ice forms on the leading edge of the wing the boot inflates and expands.  Cracking the ice that formed over it.  Which falls away from the wing.

Commercial jets have larger airfoils.  And require a larger anti-icing system.  The most common being a pneumatic manifold system that ducts hot air to areas subject to icing.  Which works thanks to a property of gas.  If you compress a gas you increase its temperature.  That’s how a diesel engine can work without sparkplugs.  The compressed air-fuel mixture gets so hot it ignites.  This property comes in handy on a jet plane as there is a readily available source of compressed air.  The jet engines.

As the air enters the jet it goes through a series of fast-spinning rotors.  As the air moves through the engine these rotors push this air into smaller and smaller spaces.  Compressing it.  Through a low-pressure compressor.  And then through a high-pressure compressor.  At which time the air temperature can be in excess of 500 degrees Fahrenheit.  It is in the high-pressure compressor that we ‘bleed’ off some of this hot and pressurized air.  We call this a bleed air system.  The air then enters a manifold which ducts it to at-risk icing areas.  From the engine cowling to the wings to the instrumentation ports.  Using the hot air to raise temperatures in these areas above the freezing temperature of water.  Thus preventing the formation of ice.

The Drawback of a Bleed Air System is Reduced Engine Efficiency

The bleed air system does more than just anti-icing.  It also pressurizes the cabin.  As well as keeps it warm.  Which is why we don’t have to dress like a crewmember on a World War II bomber when we fly.  It also powers the air conditioning system.  And the hydraulic system.  It provides the pressure for the water system.  And it even starts the jet engines.  With the source of pressurized bleed air coming from the auxiliary power unit mounted in the tail.  Or from an external ground unit.  Once the jets are running they disconnect from the auxiliary source and run on the bleed air from the engines.

There is one drawback of a bleed air system.  It bleeds air from the jet engine.  Thus reducing the efficiency of the engine.  And a less efficient engine burns more fuel.  Raising the cost of flying.  With high fuel costs and low margins airlines do everything within their power to reduce the consumption of fuel.  Which is why pilots don’t top off their fuel tanks.  They’d like to.  But extra fuel is extra weight which increases fuel consumption.  So they only take on enough fuel to get to their destination with enough reserve to go to an alternate airport.  Even though it seems risky few planes run out of fuel in flight.  Allowing the airlines to stay in business without having to raise ticket prices beyond what most people can afford.

To help airlines squeeze out more costs Boeing designed their 787 Dreamliner to be as light as possible by using more composite material and less metal.  Making it lighter.  They are also using a more efficient engine.  Engines without a bleed air system.  In fact, they eliminated the pneumatic system on the 787.  Converting the pneumatic components to electric.  Such as using electric heating elements for anti-icing.  Thus eliminating the weight of the bleed air manifold and duct system.  As well as increasing engine efficiency.  Because all engine energy goes to making thrust.  Which reduces fuel consumption.  The key to profitability and survival in the airline industry.

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Allegiant Air the most Profitable Airline despite being the least Fuel-Efficient

Posted by PITHOCRATES - September 21st, 2013

Week in Review

When people fly on vacation they’re about to spend a lot of money.  And a big cost is airfare.  Which they will try to book in advance to lock in some low prices.  This is what people think about when they are about to fly on vacation.  Not carbon emissions (see America’s greenest airlines by N.B. posted 9/17/2013 on The Economist).

IN THEORY, fuel efficiency should be a win-win proposition for airlines. Burning less fuel is better for the environment and the carriers’ bottom lines—fuel is generally their biggest single cost. That’s why one finding from a recent fuel-efficiency study is so surprising. In a new report (pdf), the International Council on Clean Transportation (ICCT) found that Allegiant Air, the most profitable airline on domestic American routes between 2009 and 2011, was also the least fuel-efficient airline during 2010.

…The upshot is obvious: according to the researchers, the financial benefits of fuel efficiency have not been enough to force convergence—”Fuel prices alone may not be a sufficient driver of in-service efficiency across all airlines…. Fixed equipment costs, maintenance costs, labour agreements, and network structure can all sometimes exert countervailing pressures against the tendency for high fuel prices to drive efficiency improvements.”

So if the bottom line cannot force airlines to be more fuel efficient, what can? The researchers suggest that airlines can start by making more data available to the public…Cars come with fuel-efficiency ratings, and appliances come with energy-efficiency stickers. Maybe flights should include that kind of data, too, so that concerned passengers can make an informed choice.

Allegiant Air is a low-cost no-frills airline that caters to people going on vacation.  And when you’re on vacation you are taking a break from worrying.  About the bills.  The job.  Even the environment.  You may drive a Prius back at home.  But for two 4-hour flights a year (to and from your vacation spot) you’re just not going to worry about carbon emissions.  Because you’re on vacation.

Allegiant Air flies predominantly MD-80s that sit about 166 people.  An MD-80 is basically a stretched out DC-9.  These have two tail-mounted turbojet engines.  The least fuel-efficient engines on planes.  But these turbojet engines are small and can attach to the fuselage at the tail.  Allowing it to use shorter landing gear.  These planes sit lower to the ground and can be serviced with the smaller jet-ways you see at smaller airports.  Where Allegiant Air flies out of nonstop to their vacation destinations.  People like not having to make a connecting flight.  And will gladly dump a few extra tons of carbon into the atmosphere for this convenience.

The Allegiant Air business model includes other things to help keep costs down.  They are nonunion.  They also fly only a few flights a week at each airport.  Allowing a smaller crew to service and maintain their fleet.  These labor savings greatly offset the poorer fuel efficiency of their engines.  The airlines that have unions (pilots, flight attendants, maintenance, etc.) all share something in common.  Recurring bankruptcies.  Which Allegiant Air doesn’t have.  Despite their higher fuel costs.

Fuel costs are an airlines greatest cost.  Especially for the long-haul routes.  Which burn a lot more fuel per flight than the typical Allegiant Air flight.  Which is why the fuel-efficient Boeing 787 is so attractive to them.  As they need to squeeze every dime out of their fuel costs as they can.  To offset their high union labor costs.  Those very costs that return a lot of airlines to bankruptcy.

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Trucks, Trains, Ships and Planes

Posted by PITHOCRATES - August 21st, 2013

Technology 101

Big Over-the-Road Tractor Trailer Trucks have Big Wheels so they can have Big Brakes

If you buy a big boat chances are you have a truck or a big SUV to pull it.  For rarely do you see a small car pulling a large boat.  Have you ever wondered why?  A small car can easily pull a large boat on a level (or a near level) surface.  That’s not the problem.  The problem is stopping once it gets moving.  For that is a lot of mass.  Creating a lot of kinetic energy (one half of the mass times velocity squared).  Which is dissipated as heat as brake shoes or pads rub against the wheels.  This is why you need a big truck or SUV to pull a boat.  So you can stop it once it gets moving.

Big trucks and big SUVs have big wheels and big brakes.  Large areas where brake pads/shoes press against a rotating wheel.  All of which is heavy duty equipment.  That can grab onto to those wheels and slow them down.  Converting that kinetic energy into heat.  This is why the big over-the-road tractor trailer trucks have big wheels.  So they can have big enough brakes to stop that huge mass once it gets moving.  Without the brakes turning white hot and melting.  Properly equipped trucks can carry great loads.  Moving freight safely across our highways and byways.  But there is a limit to what they can carry.  Too much weight spread between too few axles will pound the road apart.  Which is why the state police weighs our trucks.  To make sure they have enough axles supporting the load they’re carrying.  So they don’t break up our roads.  And that they can safely stop.

It’s a little different with trains.  All train cars have a fixed number of axles.  But you will notice the size of the cars differ.  Big oversized boxcars carry a lot of freight.  But it’s more big than heavy.  Heavy freight, on the other hand, like coal, you will see in smaller cars.  So the weight they carry doesn’t exceed the permissible weight/axle.  If you ever sat at a railroad crossing as a train passed you’ve probably noticed that the rail moves as the train travels across.  Watch a section of rail the next time you’re stopped by a train.  And you will see the rail sink a little beneath the axle as it passes over.

If a Ship is Watertight and Properly Balanced it can be covered in Green Water and Rise back to the Surface

So the various sizes of train cars (i.e., rolling stock) keeps each car from being overloaded.  Unlike a truck.  Steel haulers and gravel trains (i.e., dump trucks) have numerous axles beneath the load they’re carrying.  But these axles are retractable.  For the more wheels in contact with the road the more fuel is needed to overcome the friction between the tires and the road.  And the more tires in contact with the road the more tire wear there is.  Tires and fuel are expensive.  So truckers like to have as few tires in contact with the road as possible.  When they’re running empty they will have as many of these wheels retracted up as possible.  Something you can’t do with a train.

That said, a train’s weight is critical for the safe operation of a train.  In particular, stopping a train.  The longer a train is the more distance it takes to stop.  It is hard to overload a particular car in the string of cars (i.e., consist) but the total weight tells engineers how fast they can go.  How much they must slow down for curves.  How much distance they need to bring a train to a stop.  And how many handbrakes to set to keep the train from rolling away after the pressure bleeds out of the train line (i.e., the air brakes).  You do this right and it’s safe sailing over the rails.  Ships, on the other hand, have other concerns when it comes to weight.

Ships float.  Because of buoyancy.  The weight of the load presses down on the water while the surface of the water presses back against the ship.  But where you place that weight in a ship makes a big difference.  For a ship needs to maintain a certain amount of freeboard.  The distance between the surface of the water and the deck.  Waves toss ships up and down.  At best you just want water spray splashing onto your deck.  At worst you get solid water (i.e., green water).  If a ship is watertight and properly balanced it can be covered in green water and rise back to the surface.  But if a ship is loaded improperly and lists to one side or is low in the bow it reduces freeboard.  Increases green water.  And makes it less likely to be able to safely weather bad seas.  The SS Edmund Fitzgerald sank in 1975 while crossing Lake Superior in one of the worst storms ever.  She was taking on water.  Increasing her weight and lowering her into the water.  Losing freeboard.  Had increasing amounts of green water across her deck.  To the point that a couple of monster waves crashed over her and submerged her and she never returned to the surface.  It happened so fast that the crew was unable to give out a distress signal.  And as she disappeared below the surface her engine was still turning the propeller.  Driving her into the bottom of the lake.  Breaking the ship in two.  And the torque of the spinning propeller twisting the stern upside down.

Airplanes are the only Mode of Transportation that has two Systems to Carry their Load

One of the worst maritime disasters on the Great Lakes was the sinking of the SS Eastland.  Resulting in the largest loss of life in a shipwreck on the Great Lakes.  In total 844 passengers and crew died.  Was this in a storm like the SS Edmund Fitzgerald?  No.  The SS Eastland was tied to the dock on the Chicago River.  The passengers all went over to one side of the ship.  And the mass of people on one side of the ship caused the ship to capsize.  While tied to the dock.  On the Chicago River.  Because of this shift in weight.  Which can have catastrophic results.  As it can on airplanes.  There’s a sad YouTube video of a cargo 747 taking off.  You then see the nose go up and the plane fall out of the sky.  Probably because the weight slid backwards in the plane.  Shifting the center of gravity.  Causing the nose of the plane to pitch up.  Which disrupted the airflow over the wings.  Causing them to stall.  And with no lift the plane just fell out of the sky.

Airplanes are unique in one way.  They are the only mode of transportation that has two systems to carry their weight.  On the ground the landing gear carries the load.  In the air the wings carry the load.  Which makes taking off and landing the most dangerous parts of flying.  Because a plane has to accelerate rapidly down the runway so the wings begin producing lift.  Once they do the weight of the aircraft begins to transfer from the landing gear to the wings.  Allowing greater speeds.  However, if something goes wrong that interferes with the wings producing lift the wings will be unable to carry the weight of the plane.  And it will fall out of the sky.  Back onto the landing gear.  But once the plane leaves the runway there is nothing the landing gear can gently settle on.  And with no altitude to turn or to glide back to a runway the plane will fall out of the sky wherever it is.  Often with catastrophic results.

A plane has a lot of mass.  And a lot of velocity.  Giving it great kinetic energy.  It takes long runways to travel fast enough to transfer the weight of the aircraft from the landing gear to the wings.  And it takes a long, shallow approach to land an airplane.  So the wheels touch down gently while slowly picking up the weight of the aircraft as the wings lose lift.  And it takes a long runway to slow the plane down to a stop.  Using reverse thrusters to convert that kinetic energy into heat.  Sometimes even running out of runway before bringing the plane to a stop.  No other mode of transportation has this additional complication of travelling.  Transferring the weight from one system to another.  The most dangerous part of flying.  Yet despite this very dangerous transformation flying is the safest mode of traveling.  Because the majority of flying is up in the air in miles of emptiness.  Where if something happens a skilled pilot has time to regain control of the aircraft.  And bring it down safely.

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Elon Musk’s Hyperloop is Probably as Good an Idea as High-Speed Rail

Posted by PITHOCRATES - August 18th, 2013

Week in Review

We transport heavy freight over land by train.  And transport people over land by plane.  Have you ever wondered why we do this?  Especially you train enthusiasts who would love to travel by train more often?  Here’s why.  Cost.  Railroads are incredibly expensive to build, maintain and operate.  Because there is rail infrastructure from point A to point B.  And at their terminus points.    Whereas planes fly through the air between point A and point B.  Without the need for infrastructure.  Except at their terminus points.  Making railroading far more expensive than flying.

If planes are so much cheaper to operate than trains then why don’t we use planes to transport all our freight?  Here’s why.  Price.  Trains charge by the ton of freight they transport.  And they can carry a lot of tons.  An enormous amount of tons.  Which makes the per-ton price relatively inexpensive.  A plane can carry nowhere near the amount of freight a train can carry.  It’s not even close.  Which makes the per-ton price to ship by plane very, very expensive.  So only high priority freight that has to be somewhere fast will travel by plane.  Heavy bulk items all travel by train.

We may be having an obesity problem but in the grand scheme of things people are very light.  But take up a lot of volume for their given weight.  The space their body physically occupies.  And the greater space around them containing the air they must breathe.  That holds the food and drink they must consume.  And the toilets they need to relieve themselves.  Now let’s look at a 747-400 with 450 passengers on board.  Let’s say the average weight of everyone comes to 195 pounds.  So the total flying weight of the people comes to 87,750 pounds.  Assuming flying costs for one trip at $125,000 that comes to $1.42 per pound.  If we add 15% for overhead and profit we get a $1.64 per-pound ticket price.  So a 275-pound man must pay $451 to fly.  While a 120-pound woman must pay $197 to fly.  Of course we don’t charge people by the pound to fly.  At least, not yet.  No, we charge per person.  So the per-person price is $224, where the lighter people subsidize the price of the heavier people.

The 747-400 is one of the most successful airplanes in the world because it can pack so many people on board.  Reducing the per-person cost.  Now let’s look at that same cost being distributed over only 28 passengers.  When we do the per-person cost comes to $4,464.  Adding 15% for overhead and markup brings the per-person price to $5,134.  A price so high that few people could afford to pay for it.  Or would choose to pay for it.  And this is why we transport people by plane.  That can carry a lot of people.  And we transport heavy freight by train.  That can carry a lot of tons.  And why this idea will probably not work (see Elon Musk Is Dead Wrong About The Cost Of The Hyperloop: In Reality It Would Be $100 Billion by Jim Edwards posted 8/16/2013 on Business Insider).

Tesla CEO Elon Musk’s plan for a space-age Hyperloop transport system between Los Angeles and San Francisco would cost only $7.5 billion, he said in the plans he published recently…

But the New York Times did us all a favor by calculating the true cost of the Hyperloop: It’s going to be ~$100 billion…

The Hyperloop is a pressurized tube system in which passenger cars zoom around on an air cushion, at up to 800 miles an hour.

There is no greater infrastructure cost between point A and point B than there is for high-speed rail.  Because these rails have to be dedicated rails.  With no grade crossings.  All other traffic either tunnels underneath or bridges overhead.  These tracks are electrified.  Adding more infrastructure than just the tracks.  All of which has to be maintained to exacting standards to allow high-speed trains to travel safely.  Which is why high-speed rail is the most costly form of transportation.  Why there are no private high-speed rail lines as only taxpayer subsidies can pay for these.  And for all these costs these trains just don’t transport a lot of people.  Making high-speed rail the most inefficient way to transport people.

The Hyperloop will be more costly than high-speed rail as this is an elevated tube system of exacting standards.  Requiring great costs to build, maintain and operate.  While transporting so few people per trip (28 per capsule).  Not to mention high-speed travel is very dangerous.  Unless it is up in the air separated by miles of open air.  But on the ground?  When a high-speed train crashes it is pretty catastrophic.  And it can tear up the infrastructure it travels on.  Shutting the line down.  So traveling 800 miles an hour inside a narrow tube is probably not the safest thing to do.

Of course the biggest fear in a system like this is some politician will pass legislation to build it.  Because of all the taxpayer-subsidized union jobs it will create.  As they are constantly trying to build high-speed rail for the same reasons.  For the politics.  Not because it’s a good idea.  For any idea requiring taxpayer subsidies is rarely a good idea.

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One Passenger Airline charging by the Passenger’s Weight may offer new Funding Idea for Obamacare

Posted by PITHOCRATES - April 7th, 2013

Week in Review

When the price of oil soars it doesn’t affect the railroads that much.  Because fuel costs are not their greatest cost.  Maintaining that massive infrastructure is.  For wherever a train travels there has to be track.  It’s different for the airlines.  The only infrastructure they have is at the airports.  And the traffic control centers that keep order in the sky.  Once a plane is off the ground it doesn’t need anything but fuel in its tanks to go somewhere.  And because the flying infrastructure is so much less than the railroad infrastructure fuel costs are a much larger cost.  In fact, it’s their greatest cost of flying.  So when fuel costs rise ticket prices rise along with them.  And they start charging more bag fees.  As well as any other fee they can charge you to offset these soaring fuel costs.

Boeing made their 787, the Dreamliner, exceptionally light.  To reduce flying costs.  They used a lot of composite materials.  Two large engines because they’re lighter than 4 smaller engines.  They even used a new lithium-ion battery system to start up their auxiliary power unit.  And made it fly-by-wire to eliminate the hydraulic system that normally operates the control surfaces.  They did all of these things to fight the biggest enemy they have in flying.  Weight.  For the greater the weight the more fuel they burn.  And the less profitable they are.

Freight airlines charge their customers by the weight of the freight they wish to ship.  Because there is a direct correlation between the weight of their freight and the amount of fuel they have to burn to carry that freight.  In fact, all shippers charge by the weight.  Because in transportation weight is everything.  But there is one mode of transportation that we don’t charge by the weight.  Passenger air travel.  Until now, that is (see A tax on overweight airline passengers: a brutal airline policy by Robin Abcarian posted 4/3/2013 on the Los Angeles Times).

When teensy-weensy Samoa Airlines debuted its pay-by-the-kilo policy in January, I doubt it expected to set off an international controversy about fat discrimination.

But that’s what happened when news seeped out this week after the airline’s chief executive, Chris Langton, told ABC News radio in Australia that the system is not only fair but destined to catch on.

“Doesn’t matter whether you’re carrying freight or people,” explained Langton. “We’ve amalgamated the two and worked out a figure per kilo.”

Samoa Air, he added, has always weighed the human and non-human cargo it carries. “As any airline operator knows, they don’t run on seats, they run on weight,” said Langton. “There’s no doubt in my mind this is the concept of the future because anybody who travels has felt they’ve paid for half the passenger that’s sitting next to them…”

“Samoa Air, Introducing a world first: ‘Pay only for what you weigh’! We at Samoa Air are keeping airfares fair, by charging our passengers only for what they weigh. You are the master of your Air’fair’, you decide how much (or little) your ticket will cost. No more exorbitant excess baggage fees, or being charged for baggage you may not carry. Your weight plus your baggage items, is what you pay for. Simple. The Sky’s the Limit..!”

One bright note to this policy: Families with small children, who often feel persecuted when they travel, stand to benefit most from this policy. Since Samoa no longer charges by the seat, it will cost them a lot less to fly than it did before.

The appeal of this policy depends on your perspective.  If you’re of average weight sitting next to someone spilling over their seat into yours it may bother you knowing that you each paid the same price for a seat and resent the person encroaching on your seat.  But if you paid per the weight you bring onto the airplane then that person paid for the right to spill over into your seat.  Which they no doubt will do without worrying about how you feel.  As they paid more for their ticket than you paid for yours.  So the person who weighs less will get a discount to suffer the encroachment.  While the person who weighs more will have to pay a premium for the privilege to encroach.

Under the current system the people who weigh less subsidize the ticket prices of those who weigh more.  It’s not fair.  But it does save people the embarrassment of getting onto a scale when purchasing a ticket.  So should all airlines charge like all other modes of transportation?  Or should they continue to subsidize the obese?  Should we be fair?  Or should we be kind?

Chances are that government would step in and prevent airlines from charging by the weight.  Calling it a hate crime.  Even while they are waging a war on the obese themselves. Telling us what size soda we can buy.  And regulating many other aspects of our lives.  Especially now with Obamacare.  Because the obese are burdening our health care system with their health problems the government now has the right to regulate our lives.  And they have no problem calling us fat and obese.  But a private airline starts charging by the weight of the passenger?  Just don’t see how the government will allow that.  For it’s one thing for them to bully us.  But they won’t let these private businesses hurt people’s feelings by being fair.  So the people who are not overweight will continue to subsidize the flying cost of those who are overweight.

Until the government determines obese people are causing an unfair burden on society.  The obese have more health issues.  Which will consume more limited health care resources.  Also, flying these heavier people around will burn more fuel.  Putting more carbon emissions into the air.  Causing more breathing problems for everyone else.  As well as killing the planet with more global warming.  So while the airlines may not want to weigh people when selling them a ticket because of the potential backlash, the government won’t have a problem.  To cut the high cost of health care and to save the planet from global warming caused by carbon emissions they may even introduce a ‘fat’ tax.  Like any other sin tax.  To encourage people to choose to be healthier.  And to punish those who choose not to.  If they can force us to buy health insurance what can stop them from accessing a ‘fat’ tax?  Especially when they do have the right to tax us.

This is where national health care can take us.  When they begin paying the bill for health care they will have the right to do almost anything if they can identify it as a heath care issue.  Because it’s in the national interest.  They’ve painted bulls-eyes on the backs of smokers.  And drinkers.  With tobacco and alcohol taxes.  And you know they would love to tax us for being fat.  Perhaps even having our doctors file our weight with the IRS.  So they can bump our tax rates based on how obese we are.  If the tax dollars pay for health care they will say they have that right.  As the obese consume an unfair amount of those limited tax dollars.  Anything is possible with an out of control growing federal government faced with trillion dollar deficits.  Especially when they can call it a health care issue.

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