Let's Play the Plane Spotting Game! Yay!

Okay so I figured maybe I'd pick something in aviation that you can use every time you're sitting at your gate looking out the window (that is if you're me). I love plane spotting, which involves looking for both aircraft types and liveries. Tonight I thought I'd show you how to tell the difference between the bigger Boeing jets, the important and most common airplanes you'll see.

B747-100, SP, 200,300,400,800

The 747 is probably the easiest plane to spot. You just need to look for the forward double-deck "hump" and 4 pod engines. It's the only aircraft anywhere in the world that has those two defining features. Now to distinguish between the types:

B747-100,200,300,400 -> These models all look the same from the outside and just involve mechanical and electrical upgrades, ie not airframe or engine modifications that are really noticeable from far away.

B747 SP -> This is an extremely rare aircraft and I have never seen it. It is not flown by any airline that enters the U.S. currently. Essentially, the fuselage behind the hump is shortened inorder to allow the aircraft to have better range and be able to fly out of shorter runways.

B747-800 -> This plane hasn't been delivered yet but will just have an extended double deck as well as fuselage.

B777-200,200ER,200LR,300,300ER

Telling the difference between the variants isn't important since they just involve different MTOWs and ranges and not structural modifications that are externally obvious.

Ok, the 777 can be difficult to distinguish between the 767 and some Airbuses. First of all, the 777 is the largest twin engine aircraft on the market. But from a distance, its size can be difficult to pinpoint. My way to identify it are those big beautiful GE90s. Its two engines are the largest, most powerful turbofans ever made. You'll notice in the picture, that its engines are nearly 2/3 the entire diameter of the fuselage of the aircraft, a feature unique to the 777. This'll be more evident after looking at the other planes.

B767,etc

Just as the B777, the variants are unimportant for non-intense airplane nerds.

Although the 767 came first, it just looks a smaller version of the 777 since they are both widebodies. You can tell its smaller by the distance from the cockpit windows to the bottom of the fuselage. The nose is also a bit more rounded. But the better give away it is comparatively smaller engines to the 777. So look for the same relative shape as the 777 but a significantly smaller engine.

B757, etc

Variants once again are not important.

The 757 is a bit of an odd ball. If an airplane could be, it is lanky. Since it is boeing's largest narrowbody, its fuselage is quite narrow but long, has a large tail and horizontal stabilizers, and long landing gear. But the way I usually notice it is its nose. It has an asymmetric nose, with a long down-sloping top section with the cockpit windows and an almost non-existing bottom slope. It kind of looks like an Amtrack locomotive. If you see it from straight on, its size and narrow fuselage will quite clearly give it away.

B737,100,200,800/NG,etc...

Ok, there are really only two variants that are important, the old versions and new versions. The differences are only noticeable in the engines.

First of all, the 737 is Boeing's smallest narrowbody (although it is not nearly as small the CRJs and ERJs). It is short but has a relatively symmetric nose unlike the 757. To me what stands out is how low it is to the ground. It kinda reminds me of a Corgi, a rotund Corgi. In fact its so low to the ground, that the engine cowlings aren't circular, but are cut off at the bottom to prevent the engines from striking the ground when the wing flexes on touch down.

The reason it is so low is because its an old enough design that it was originally designed with turbojets instead of turbofans, which are far more tubular and narrow as shown here:

And this is also how you spot older versions, as in pre-NG (next generation) 737s, by the long, tubular engines instead of wider, shorter turbofans.

Now here I have just shown the differences between the Boeing aircraft. The real challenge is telling the differences between some Airbuses and Boeings which fulfill the same size and range specifications. And just incase you didn't know, a widebody has two aisles inside, a narrowbody one.

On the Beach at Night Alone

I'm sorry dear but I haven't been able to find a Whitman poem about the home yet. But here's one I found that I liked:

On the Beach at Night Alone

By Walt Whitman

On the beach at night alone,
As the old mother sways her to and fro singing her husky song,
As I watch the bright stars shining, I think a thought of the clef
of the universes and of the future.

A vast similitude interlocks all,
All spheres, grown, ungrown, small, large, suns, moons, planets,
All distances of place however wide,
All distances of time, all inanimate forms,
All souls, all living bodies though they be ever so different, or in
different worlds,
All gaseous, watery, vegetable, mineral processes, the fishes, the brutes,
All nations, colors, barbarisms, civilizations, languages,
All identities that have existed or may exist on this globe, or any globe,
All lives and deaths, all of the past, present, future,
This vast similitude spans them, and always has spann'd,
And shall forever span them and compactly hold and enclose them.

Spirit Whose Work is Done

Spirit Whose Work is Done (1865)

By Walt Whitman

SPIRIT whose work is done! spirit of dreadful hours!
Ere, departing, fade from my eyes your forests of bayonets;
Spirit of gloomiest fears and doubts, (yet onward ever unfaltering pressing;)
Spirit of many a solemn day, and many a savage scene! Electric spirit!
That with muttering voice, through the war now closed, like a tireless phantom flitted,	5
Rousing the land with breath of flame, while you beat and beat the drum;
—Now, as the sound of the drum, hollow and harsh to the last, reverberates round me;
As your ranks, your immortal ranks, return, return from the battles;
While the muskets of the young men yet lean over their shoulders;
While I look on the bayonets bristling over their shoulders;	10
While those slanted bayonets, whole forests of them, appearing in the distance, approach and pass on, returning homeward,
Moving with steady motion, swaying to and fro, to the right and left,
Evenly, lightly rising and falling, as the steps keep time;
—Spirit of hours I knew, all hectic red one day, but pale as death next day;
Touch my mouth, ere you depart—press my lips close!	15
Leave me your pulses of rage! bequeath them to me! fill me with currents convulsive!
Let them scorch and blister out of my chants, when you are gone;
Let them identify you to the future, in these songs.

Game Theory

Since you chose Game Theory I guess I'll give a little summary of what it is. To be honest, I barely understand the specifics of Game Theory, so I can't give you much more than a glossing over of what it is and perhaps an example of a "game". Game Theory is a mathematical science, and considering my trouble with advanced math, I can't go into the analytical details either.

Game Theory is a mathematical science generally used in economics to predict outcomes that depend upon human behavior. More specifically, game theory looks at different games, or situations in which a person must make a decision that affects both themselves and another person or persons. Using certain guidelines and assumptions, various theorems in game theory can predict what is the most likely outcome, mathematically. This systematic analysis of behavior and decision making is very useful for creating economic models, although it is certainly a hit-and-miss science when applied to the real world. The new field of behavioral economics (as opposed to classic, keynasian, etc which we looked at with Mr. Hunt) uses a lot of Game Theory.

Instead of fumbling around trying to explain more of Game Theory in general terms, I thought I'd just give the most classic example of a "game" or situation: The Prisoner's Dilemma.

'Tanya and Cinque have been arrested for robbing the Hibernia Savings Bank and placed in separate isolation cells. Both care much more about their personal freedom than about the welfare of their accomplice. A clever prosecutor makes the following offer to each. “You may choose to confess or remain silent. If you confess and your accomplice remains silent I will drop all charges against you and use your testimony to ensure that your accomplice does serious time. Likewise, if your accomplice confesses while you remain silent, they will go free while you do the time. If you both confess I get two convictions, but I'll see to it that you both get early parole. If you both remain silent, I'll have to settle for token sentences on firearms possession charges. If you wish to confess, you must leave a note with the jailer before my return tomorrow morning.”'

In non-mathematical terms, the question is what will each prisoner decide and why. As a quick side note, this is a "zero-sum game" which means that a subject can only do better at the expense of someone else. This simple incarnation of Game Theory is all that I know about right now. Anyway, many "games" involve whether cooperation between the two individuals will result in better situations for both, and then if the two will cooperate in the end. Using the simple Prisoners' Dilemma, we can easily deduce that the best results for both prisoners would be yielded by neither betraying the other. But the inherent quality of the prisoners is that they are solely interested in securing their own freedom. As a result, according to Game Theory, both prisoners will confess by applying rational decision-making, resulting in greater sentences than if they had cooperated. Why exact that is is far better explained by wikipedia:

"In this game, as in all game theory, the only concern of each individual player (prisoner) is maximizing his or her own payoff, without any concern for the other player's payoff. The unique equilibrium for this game is a Pareto-suboptimal solution, that is, rational choice leads the two players to both play defect, even though each player's individual reward would be greater if they both played cooperatively.
In the classic form of this game, cooperating is strictly dominated by defecting, so that the only possible equilibrium for the game is for all players to defect. No matter what the other player does, one player will always gain a greater payoff by playing defect. Since in any situation playing defect is more beneficial than cooperating, all rational players will play defect, all things being equal."

An "equilibrium" I believe is simply an expected, repeated result for the game. Additionally, a "Pareto-suboptimal solution" means that it is a situation wherein one can only experience betterment (usually meaning in economic wealth terms) through the worsening of another. I have to stop here because my dad needs to use the computer. There was one more thing I was going to talk about, so I guess I'll have to post it separately later. I hope this made some sense.

Where O Where Could That Fishy Be?

So Ally I thought maybe I should post some different topics for you to choose from for my next post:

In Aviation:
Turbojet vs. Turbofan
A Summary of Airfoils and Flight Surfaces

In Economics:
Classic Economic Paradoxes
China and the U.S.

Game Theory

In History:
Common Misconceptions in the Study of World War II
The Origins of the Post-WWII Boom (this one's kind of a mix of econ and history)

Any one of these is fine.

Im sure youll be angry when you learn that you have to choose ;)

The Future of ATC

I thought that instead of continuing on the same tangent for a while on engines, I'd throw in something different.

One of the most exciting and crucial new technologies that is currently undergoing testing is an aircraft communication system called ADS-B. ADS-B stands for Automatic Dependent Surveillance-Broadcast. As the name implies, it automatically allows each plane with the system to continuously communicate with both other aircraft and Air Traffic Control (ATC). The implementation of ADS-B has the potential to both increase safety in commercial aviation while lessening airline financial losses.

How does ADS-B differ from the current ATC system?

The way the ATC system works now, pilots are almost entirely dependent on the guidance of overworked air traffic controllers in order to maintain proper spacing between their aircraft and others in the airspace or on route. Although most aircraft have collision avoidance systems, which combine on aircraft radar and plane-to-plane line-of-sight communication, the old TCASs (Traffic Collision Avoidance Systems) are basic and can only be used for guidance in the event of a imminent collision with another aircraft. Otherwise pilots have to blindly follow the instructions of the air traffic controllers unless they visually spot a potential conflict, which is FAR harder said than done considering how quickly the aircraft are traveling.

ADS-B on the other hand will allow pilots to clearly see where all other aircraft are in relation to them on a cockpit display. Instead of relying on expensive radar systems, ADS-B is a network of various communication devices including in plane hardware, GPS, and ground stations. The aircraft calculates it position using GPS, and then broadcasts it to all other nearby aircraft, either directly by line-of-sight or relayed through ground stations (which also feed into ATC). This way, pilots will be able to perform evasive maneuvers far before visual contact (if the aircraft is operating under visual flight rules or "VFR") or prior to ATC intervention (in both VFR and instrument conditions "IFR").



How will ADS-B increase safety?

The most dangerous portion of a flight is when the aircraft is in the vicinity of an airport. The shear number of aircraft operating around the world's main airports at any one time is staggering. ADS-B allows pilots to get a better picture of their surroundings than if solely communicating with ATC Ground, Tower, Departure, and Approach Controls. The best example of the potential of ADS-B is solving the problems with runway incursions.

Runway Incursions occur far more frequently than you would think. A runway incursion quite simply is when an aircraft moves or lands on a runway without permission by ATC or one where another aircraft is already operating. Most commercial runway incursions occur in low visibility, where either the pilot doesn't realize he has entered the runway, the ground controller doesn't realize another plane is already landing or taking off on the runway, or a pilot misidentifies a runway when landing. Surprising only a few of the largest airports have a system for monitoring the position of aircraft on the ground since radar isn't effective on ground level. So the majority of controllers rely on visually watching aircraft (through the super advanced technology of binoculars) or by position reports and very wide spacing in IFR conditions.

ADS-B will allow both pilots and controllers to know where each aircraft is on the ground, and through surface movement management software (SURF IA*), merge aircraft positions with taxiways and runways. ADS-B with SURF IA automatically tells the pilot when he enters a runway where another aircraft is already on approach. SURF IA can also inform the pilot if he's lined up with the wrong runway among other functions. Since the deadliest aircraft accident of all time occur when two 747s collided on a runway in fog, the implementation of a system that shows both pilots and controllers exactly where everyone is and what their probable intentions are is greatly welcomed by the aviation community. Tests on a U.S. Airways Airbus A330 with ADS-B and SURF IA hardware and software funded by the FAA has already shown the potential for the systems.

How will ADS-B increase airline revenues?

The primary reason is spacing between aircraft. The FAA has already stated that with the implementation of ADS-B, it will allow aircraft to fly closer together. This means planes will be able to take-off and land more quickly, thus spending less time burning fuel on the ground or in the air waiting for clearance to take-off or land. This means fewer delays, which are extremely costly for airlines. More aircraft will also be able to fly on the most efficient routes between destinations at one time. For example, between London's Heathrow and New York's JRK, there is one route and altitude which for most aircraft allows for the most fuel efficiency. But due to the large spacing required both horizontally and vertically, only a certain number of planes can be on this route at one time. With ADS-B more aircraft can be tolerated on that route, lessening the need for airlines to send their aircraft on less efficient paths.

These advantages also work in favor of passengers, since there will be fewer delays in the event of IFR conditions as well as allow for more frequent flights between popular destinations.

The Implementation of ADS-B

The FAA is planning to slowly phase in ADS-B in the next ten years, while simultaneously decommissioning the now antiquated radar systems across the country. ADS-B is expensive for both federally controlled airports and the airlines, who have to pay for the hardware to be installed in each aircraft. As a result, much of the program is dependent on FAA funding allowed by Congress, so the timetables for the full implementation of ADS-B are very flexible knowing the nature of Congress. If federal funding drops, airlines will have little incentive to take the short term financial losses on buying the systems, since the long term benefits will appear less likely. Also, international flights will still require the old systems and require pilots to understand the old radar vectoring, spacing, radar, and TCAS rules due to small likelihood the rest of the world will buy into the U.S.'s new ADS-B national network systems any time "soon".

Nevertheless, ADS-B and its associated systems such as SURF IA have a great potential to increase both the safety margin and revenues for the airlines, while simultaneously making traveling a more enjoyable experience for the average passenger.

*SURF IA is not a general acronym, but the name of a software system jointly developed by the avionics divisions of ACSS and Honeywell. I just used it as an acronym since as of now, it is the only software undergoing FAA testing that fulfills the role of surface movement management utilizing ADS-B technologies.

Jet Engines

In general, as wiki says, a jet engine "discharges a fast moving jet of fluid to generate thrust in accordance with Newton's laws of motion" (the 3rd law is for every action there is an equal and opposite reaction). Before we can get into the different types, I figure we should look at how exactly a jet engine works. A normal jet engine takes in a small quantity of fast moving air, compresses it, adds fuel, and ignites the fuel/air mixture, thus expelling the expanding gases out of the back of the turbine. Here's a simple diagram:


Another key aspect of the engine shown in the diagram is the rear turbine. A large portion of the efficiency of the engine is due to the expanding gases rotating the rear turbines as they exit the engine. The turbine in turn drives the compressors and fans (if the engine is a turbofan). This means that after the initial starting of the engine, nothing but the ignition of the fuel/air mixture and it passing out the back is causing the compressors and turbine to spin. In this diagram, you can more clearly see the various stages of the jet engine and how they are mechanically linked. The fan in front of the low-pressure compressor is not a feature on the basic turbojet which we are looking at. We will look at turbofasn when I go over the different types of jet engines.



One of the greatest advantages of jet engines is their simplicity and thus they are designed to be as simple as possible (or at least they were). This can be clearly seen in how the low-pressure and high-pressure compressors are linked to their respective turbines. The low-pressure compressor rotates at a slower speed, so it is driven by turbine that is rotating more slowly due to its larger diameter, thus decreasing the pressure of the air that passes through it. Then the high-pressure compressor is driven faster by a smaller diameter turbine. The differences in speed between the two compressors could be created by gearing, such as with the gears on a bicycle, but this would invite added opportunity for failures since in general, the more moving parts, the greater the probably something will fail. This fundamental principle is the reason why jet engines are so reliable when compared to reciprocating engines (such as in prop planes or cars). While jet engines operate at very high temperatures and RPMs, the stresses are not so great as with rocket engines, where the volatility of the fuels (such as liquid oxygen and nitrogen)and the extreme temperatures are so great as to invite failure despite their simplicity.

As a quick side note, the newest developments in jet engines are actually increasing their complexity in an effort to increase fuel efficiency, such as the use of gearing that I previously stated was generally avoided in the past. But with today's advanced understanding of thermodynamics and material sciences, engineers can add more complexity without increasing the probability of an engine failure too much. I might expand on this some time later.

I figure I should stop here. Certainly everything I've mentioned can be greatly elaborated on. Jet engines are very simple machines and usually I feel like people overthink how they work. That said, while the principles are simple, we can spend endless posts looking at the details about how they are put together, the different types, etc. Probably we'll just look at the types and finish there. That is unless you have other questions. I suppose we'll see.