Federal Regulators find no Problem with Tesla Battery Design after one Burst into Flames this Month

Posted by PITHOCRATES - October 27th, 2013

Week in Review

The Boeing 787 Dreamliner is a state-of-the-art fuel-efficient intercontinental jetliner.  Something that made airlines dealing with razor-thin margins and rising fuel prices stand up and take notice.  This was an airplane that they wanted.  And how did they squeeze these fuel savings out of the Dreamliner?  Well, they used more composite materials than before.  Reducing the amount of heavier metals.  And they eliminated some other ‘heavy’ metal in a way that increased engine efficiency.  By eliminating pneumatic systems and replacing them with electric systems.  Which eliminated the bleed air system that bled efficiency from the jet engines.  And removing all the metal ductwork that piped that hot pressurized air throughout the aircraft.  Such as to the anti-icing systems in the wings.  Which they replaced with electric heaters.

The Boeing 787 is the most electric plane in commercial aviation.  It uses an enormous amount of electric power.  Which requires powerful backup batteries.  Lithium-ion batteries.  That have a very high energy density.  Created from powerful chemical reactions.  Requiring complex controllers to regulate the power, temperature and pressure in the batteries to try and prevent a ‘thermal runaway’.  Especially during charging.  Which happened a few times.  Starting a fire or two.  Prompting the FAA to action.  And grounding the entire 787 Dreamliner fleet because of these high energy density batteries.

Electric cars also use these high energy density batteries.  And some of them have caught fire.  But federal regulators aren’t taking any electric cars off of the street (see Tesla dodges full investigation after fiery crash by Charles Riley posted 10/25/2013 on CNNMoney).

Federal regulators have decided not to open an official investigation into the crash of a Tesla Model S earlier this month that resulted in a fire in the electric car’s battery section.

The National Highway Traffic Safety Administration said that while it continually reviews vehicle complaints, the crash had not led to the discovery of any safety faults…

Auto blog Jalopnik posted photos and videos of the Seattle-area accident in early October, showing an electric Tesla Model S engulfed in flames…

Musk’s 560-word post explained the accident in his usual painstaking detail. He said the cause of the accident appeared to be a piece of metal that fell off of a semi-trailer and struck the Model S.

A fire then erupted in the car’s front battery section, but was contained to that area, the CEO wrote. No flames entered the passenger compartment.

Musk also tried to reassure his readers. “There should be absolutely zero doubt that it is safer to power a car with a battery than a large tank of highly flammable liquid,” he wrote.

Well, one thing about our roads.  They are clean as a whistle.  So although there was a piece of metal once there will never be another piece of metal on our roads.  So there is no need to add some heavy metal under the Tesla to protect the battery from pieces of metal thrown up from the road.  Increasing the weight of the electric car.  Decreasing its range.  Further discouraging people from buying them.

If that piece of metal had hit a gas tank it may have dented it.  It may have even caused it to leak.  But it wouldn’t have burst into flames.  As the millions of cars driving on our metal-strewn roads testify to every day.  Gasoline stored in a tank slung underneath a car is pretty safe.  For it’s not what we combust in our engine.  No.  First we must aerosolize the liquid into a vapor.  Mix it with oxygen.  Compress it (greatly increasing its temperature).  Then ignite it with an electric spark.  And only then will it explode.  For an explosion needs heat and pressure.  Which isn’t present in a gas tank under normal conditions.  But they do exist in lithium-ion batteries under normal conditions.  Which is why they explode.  And burst into flames.



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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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Stock Options

Posted by PITHOCRATES - April 29th, 2013

Economics 101

It takes a Lot of Time to Design, Develop and Bring to Market a Radical New Aircraft

The number one cost airlines have is fuel.  So anything that can reduce fuel consumption can cut an airline’s costs.  Aircraft manufacturers are aware of this.  And want to incorporate new fuel-saving technology into their aircraft.  Because that’s what airlines want.  And if you can give the airlines what they want they will buy your aircraft.  But sometimes new technology can be a little temperamental.  Everything doesn’t work as expected.  And sometimes problems that come up can take a long time to engineer through.  Like it did for the Boeing 787 Dream liner.

Boeing did everything they could think of to squeeze every last ounce of weight from the 787.  One thing they did is well known.  Thanks to a problem with it that caused the grounding of the entire 787 fleet.  The lithium-ion battery.  But that’s not the only weight-saving innovation of the 787.  They added Dual Electronic Flight Bags in the cockpit.  So pilots don’t have to bring bulky and heavy books aboard.  They went from conventional pneumatic architecture to more-electric architecture.  Eliminating the engine bleed air system and associated pneumatic system components.  Reducing weight and improving efficiency.  Which reduced fuel consumption.  They used simple trailing edge flaps.  Not slotted flaps.  Letting them use smaller flap track fairings (those canoe-shaped things underneath the trailing edge of the wings that operated the flaps).  Reducing drag.  And fuel consumption.  They used bigger engines with higher bypass ratios (the amount of air pulled into the fan disk but NOT used for combustion).  Increasing engine efficiency.  Reducing fuel consumption.  The use of composite materials decreased weight.  And the use of one-piece barrel sections eliminated additional joints, fasteners and splice plates.  Reducing weight.  And fuel consumption.

These and other innovations result in a fuel savings of 20% over similarly sized aircraft.  This is huge.  Which is why airlines are ordering this airplane.  But such a radical change in aircraft design comes with a lot of risks.  As the problem with the lithium-ion battery has shown.  And it takes a lot of time to design, develop and bring to market a new aircraft.  Especially one that is radically different from other airplanes.  So the decision to put the aircraft company on this course was a very risky decision.  And one that took a lot of guts.  Because so many things can go wrong.  Leading to cost overruns.  Which can delay promised delivery dates.  And Boeing had their share of those bringing the 787 to market.  Which they have worked through.  Will it be worth it?  As long as airlines want to save on fuel costs, yes.  And no problems arise that they can’t overcome.

Stock Options get Risk-Averse and Cautious CEOs to be Bold and Take Risks

These are big decisions.  Decisions that lead to great successes.  Or great failures.  Some so bad that they can bankrupt a company.  Someone has to be responsible for these decisions.  That one person sitting at the top of the corporation.  The CEO.  It is the CEO who has the ultimate say on the direction of the corporation.  And with this one decision all the resources of the corporation are marshaled together to take the corporation in this new direction.  Incurring great costs that will be on the books for years.  Making it hard to change course until these great investments pay off.  If they pay off.

These are the things CEOs have to deal with.  Not just at Boeing.  But throughout corporate America.  CEOs have to make these singular decisions that can have consequences for years to come.  Where it may take years to see if that one decision actually pays off.  There are few CEOs in the labor force.  So few can imagine the stress these people work under.  And in that pool of CEOs there are only a few that have the Midas touch.   Who can consistently take great risks while making all the right decisions.  Board members desperately want these CEOs.  Offering very generous compensation packages to lure them in.  And to keep them once they have them.  This crème de la crème of CEOs may make the big bucks.  But in exchange for that fat paycheck they do something few others can.  They make shareholders rich.  And they love making these owners rich.  For they love the thrill of the job.  Relishing that high-stress environment.  Where every little decision has great consequences.  Thriving under the kind of pressure that would leave most others whimpering in their beds.  Curled up in the fetal position.  In a pool of their own tears.

But not every corporation can get one of the crème de la crème.  They may have a great CEO.  But one that suffers from a major CEO character flaw.  Being averse to taking big risks.  Who instead wants to be a little more conservative.  And a little more cautious.  Shareholders don’t like overly cautious CEOs.  Because the people getting rich are doing it by breaking away from the pack.  By doing something different.  Abandoning convention.  Trying something bold.  And new.  Bringing something brand new to market that no one knows anything about.  But once they learn about it they can’t live without it.  This is what shareholders want.  Not cautious and conservative.  So to light a fire under these CEOs they came up with a new way to compensate them.  To appeal to their greed.  By letting them get rich if they can make that next great thing that sends the stock price soaring.  And the key to their greed is the stock option.

Stock Options provide a Powerful Incentive to bring Great New Things to Market

The CEO that creates the next big thing everyone will want to buy will send sales revenue soaring.  And with great sales revenue comes great profits.  Increasing the value of the company.  Which, in turn, makes the stock price soar.  This is what shareholders want.  A soaring stock price.  So to encourage the CEO to give them what they want they tie the CEO’s interest to their interests.  By giving the CEO stock options.  Making the sky the limit.  For the more the CEO increases the stock price the greater the CEO’s compensation.  Thus encouraging the CEO to try something bold and new.

A stock option is a right to buy a share of stock at a fixed price in the future.  Say the current stock price is $70/share.  The board of directors gives the CEO the option to buy, say, 500,000 shares of stock at $80/share up until some date in the future.  Creating a strong incentive for the CEO to raise the stock price.  The greater the CEO raises the price above $80 the greater his or her compensation.   Let’s say the CEO was bold and took a great risk.  And it pays off.  Sending the stock price soaring to $110/share.  When the CEO exercises those options he or she will buy 500,000 shares of stock from the company at $80/share.  The company gets $40 million in new capital to help finance further growth.  And the CEO will sell those 500,000 shares at the current market price of $110/share.  Pocketing $15 million.  And the shareholders, of course, get what they want.  A higher stock price.  Everyone wins.

Now let’s say that nothing spectacular happens.  And the stock price only rises to $75/share.  Because it’s below the ‘strike price’ the CEO will let these options expire.  The CEO profits nothing from these options.  But doesn’t lose anything either.  But what happens when the stock price falls because of that bold, new direction?  Causing the corporation to lose value.  As well as the shareholders.  But the CEO?  Again, the CEO will let those options expire.  And will lose no money.  Which is one of the benefits of stock options.  It got those risk-averse and cautious CEOs to take those big risks that got shareholders rich.  As there is no downside risk for the CEO.  Which is both good and bad.  On the one hand it encourages risk taking.  But on the other it encourages risk-taking.  Some CEOs will take excessive risks as they have nothing to lose.  Some will even cook the books to boost the stock price so they can exercise those options.  So it’s not a perfect system.  But they do provide a powerful incentive to bring great new things to market.  Which is what shareholders want.  And will take great risks themselves to get it.



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Boeing 787 Dreamliner, Fuel Costs, Electric Systems, Auxiliary Power Unit and Lithium-Ion Batteries

Posted by PITHOCRATES - January 23rd, 2013

Technology 101

Auxiliary Devices reduce the Power Output of the Engine available to Drive a Car Forward

If you’re middle age (or old) you may remember looking under the hood of a car.  When you could see things.  In the days of rear-wheel drive cars and big engines.  The front of the engine had a power takeoff pulley attached to the crank shaft.  The thing the pistons spun when it converted reciprocal motion into rotational motion.  Wrapped around that pulley were a lot of belts.  Sometimes three or more.  They transferred the rotational motion of the crankshaft to auxiliary devices.

These devices included the water pump that pumped engine coolant to remove the heat of combustion.  An alternator to generate electric power.  A power steering pump to make steering easier.  An air pump to inject air into the exhaust system to help complete the combustion process to reduce emissions.  (An electronic air pump has since replaced this belt-driven device.)  And an air conditioner compressor.  All of these devices reduce the power output of the engine available to drive the car forward.  Requiring more fuel.

Today’s cars have a lot more stuff under the hood.  Engines are often mounted transversely.  And the multiple belts have been replaced with one serpentine belt that winds around all of these auxiliary devices.  And engines are smaller.  With on board computers that maximize the power output of smaller engines.  That drive lighter cars.  But one thing hasn’t changed.  When you turn on the air conditioning you can still hear the engine labor under the additional load.  While burning more fuel.

The Boeing 787 Dreamliner can do what other Planes can do while Burning less Fuel

In the airline industry the greatest cost is fuel.  So anything that allows airlines to burn less fuel greatly interests the airlines.  And it’s why pilots do careful calculations to determine how much fuel to carry.  That is, to determine the absolute minimum amount of fuel to carry.  If it were up to pilots they’d top off the fuel tanks.  But if they did that the airlines could not operate profitably.  Because you have to burn fuel to carry fuel.  And the more fuel you carry the more you have to burn.  Increasing your fuel costs to the point an airline loses money.  Especially if you’re landing with a lot of fuel in your tanks.  So pilots load less fuel than they would want.  Because to get a paycheck their company has to operate at a profit.  But it doesn’t stop there.  Not for aircraft designers.

Designers have been using more plastic in airplanes.  Because plastic is lighter than metal.  So engines can burn less fuel.  These composite materials are also stronger than metal.  So less of them can replace equivalent metal components.  So engines can burn less fuel.  Airlines have also been charging more for carry-on luggage.  In part to help offset their rising fuel costs.  And in part to encourage people to carry less onto the airplane.  So engines can burn less fuel.  Then Boeing raised the bar on burning less fuel.

The Boeing 787 Dreamliner is a remarkable design.  Remarkable because it delivers what airlines want most.  An airplane that can do what other planes can do.  But does it while burning less fuel.  Boeing has used more composite material than any other manufacturer.  Making the 787 the lightest in its class.  And lighter things allow engines to burn less fuel.  But Boeing did more than just make the airplane lighter.  They used electric systems to replace hydraulic and pneumatic systems normally found on an airplane.

The 787 Dreamliner uses Lithium-Ion Batteries to start their Auxiliary Power Unit

Hydraulic and pneumatic systems bleed power from the aircraft engines.  As the engines drive pumps and compressors for these systems.  By converting these to electric systems more of the power of the engines goes to producing thrust.  Which means they burn less fuel to fly to their destination.  They even replaced the pneumatic starters (that spin the engines during starting) with a combination electric starter/generator.  Saving weight.  And reducing the complexity.  By replacing two parts (pneumatic starter and electric generator) with one (combination starter/generator).

To start the aircraft engines they first start the auxiliary power unit (APU).  The APU is typically mounted near the tail of the aircraft.  The APU provides power, lights, heating, air conditioning, etc., when the main engines aren’t running.  Some provide back up power (electric and pneumatic) should the main engines fail in flight.  The APU also drives an air compressor to provide the pneumatic power to spin the main engines for starting.  Going to all electric systems (except for the engine anti-ice system) removes the air compressor from the APU.  Reducing the weight.  And they further reduced the weight by making another change.  To the battery that starts the APU.

The 787 uses lithium-ion batteries.  Which can provide the same power larger batteries of different technologies can provide.  As lithium-ion batteries has a very high energy density.  But with great energy density comes great heat.  Some of these batteries have actually caught fire.  In electric cars.  Laptop computers.  Cell phones.  Even in Boeing 787 Dreamliners.  They’re not sure why.  And they’ve grounded the fleet until they figure out why.  It may be because they are overcharging.  Or that there are internal shorts causing a thermal runaway (releasing all the stored energy at one time).  Or the caustic electrolyte is leaking and causing a fire.  Until they determine what the problem is the 787 will remain grounded.  Making it very difficult to enjoy the cost savings of that remarkable design.



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Lithium Ion Battery Fires ground entire Boeing 787 Dreamliner Fleet

Posted by PITHOCRATES - January 20th, 2013

Week in Review

The big drawback for electric cars is range.  For after a battery powers all the electrical systems (heating, cooling, lights, etc.) what charge is left is for going places.  And if that place is more than 30 miles away few people will feel comfortable taking a chance that they will have enough charge to drive there and back.  Unless that trip is to work where the car can recharge for 8-9 hours while at work.

Range anxiety is the greatest drawback to an all-electric car.  For if you run out of charge there is only one way to get your car home.  With a tow truck.  For you can’t walk to a gas station and ask for a can of charge to pour into the battery.  Charging needs an electrical source.  And time.  So the Holy Grail of the all-electric car industry is a battery that can hold a lot of charge.  But is small and does not weigh a lot.  And can be recharged in a very short time.  Right now that Holy Grail is the lithium ion battery.

But there is a cost for this Holy Grail.  There is a lot of chemistry to do this.  Chemistry that can produce a lot of heat.  Catch fire.  And explode.  Which has happened in some electric cars.  As well as in some airplanes (see Bad Batteries Seen as Best Case for 787 Overcoming Past by Susanna Ray, Alan Levin & Peter Robison posted 1/18/2013 on Bloomberg).

Other aircraft bleed air off the engines for a pneumatic system to power a variety of critical functions, such as air conditioning. That diverts power from the engines that they could otherwise use for thrust, and means they use more fuel.

With an electrical system for the jet’s other needs, the engines become much more efficient. The 787 uses five times as much electricity as the 767, enough to power 400 homes. To jump- start a so-called auxiliary power unit that’s used on the ground and as a backup in case all the plane’s generators failed, Boeing decided on a lithium-ion battery because it holds more energy and can be quickly recharged, Mike Sinnett, the 787 project engineer, said in a briefing last week.

Those capabilities also make lithium-ion cells more flammable than other battery technology, and they can create sparks and high heat if not properly discharged. Chemicals inside the battery are also flammable and hard to extinguish because they contain their own source of oxygen, Sinnett said.

A couple of battery fires have grounded all Boeing 787 Dreamliners.  The last commercial jetliner to receive such an order was the McDonnell Douglas DC-10.   Which happened after an engine came off while taking off at O’Hare International Airport in Chicago.  Due to a maintenance error in changing out the left engine and pylon.  Causing the plane to crash.  After investigation they found the slats did not mechanically latch into position.  When the engine ripped out the hydraulic lines the slats retracted and the wing stalled.  The plane slowly banked to the left and fell out of the sky.  Killing all on board.  The DC-10s were grounded worldwide until the hydraulic lines were better protected and the slats latched to prevent them from retracting on the loss of hydraulic pressure.  Now no 787s have crashed.  But few things are deadlier to an airborne aircraft than a fire.  For there is nothing pilots can do other than to continue to fly towards an airport while the plane is consumed by fire.

Stored chemical oxygen generators in the hull of ValuJet Flight 592 were stored improperly.  They were activated.  Producing oxygen by a chemical reaction that generated a lot of heat.  The heat started a fire and the oxygen fueled it.  Once the pilots were aware of the fire they turned to the nearest airport.  But the fire consumed the airplane and fell out of the sky before they could land.  Killing all on board.

Fire on an airplane rarely ends well.  Which explains the grounding of the entire 787 fleet.  Because these lithium ion batteries run very hot when they make electricity.  And they can generate oxygen.  Which is the last thing you want on an aircraft.  However, both Airbus and Boeing are using them because they are the Holy Grail of batteries.  They’re small and light and can hold a lot of charge and nothing can recharge as fast as they can.  Which is why they are the choice for all-electric cars.  Even though some of them have caught fire.  This is the tradeoff.  Smaller and lighter batteries are smaller and lighter for a reason.  Because of powerful chemical reactions that can go wrong.  So to be safe you should park your electric car outside and away from your house.  In case it catches fire you’ll only lose your car.  And not your garage or house.  Or you can stick to the gasoline-powered car and not worry about battery fires.  Or range.



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