How does a three engine plane fly?

Question

Do two of the engine turbines spin one direction and the third spins the other direction? Wouldn't this make the thrust uneven? Apparently it doesn't, but I still wonder how it works....

Answer 1

Three-engine airplanes fly exactly the same way as single-engine, twin-engine, and four-engine airplanes.

If it is a propeller driven airplane, the pilot uses the rudder (NOT the "flaps") to correct for asymmetric thrust on takeoff when the power setting is at maximum. Asymmetric thrust is not a problem with jet engines.

There are slight twists built into most airplanes to compensate for oddities in the thrust layout, but these forces are very slight, and are easily compensated for.

For lots of information including pictures and diagrams, try an internet search on "basic aerodynamics."

A few very advanced jet engines are two-spindle designs, but the great majority of jet engines used in commercial airplanes have a single spool inside.

For lots of information, including pictures and diagrams, try an internet search on "jet engine design."

For my vote, the Boeing 727 is still the easiest airliner to fly that was ever built--three engines and all! I flew one before moving up to the 747.

Answer 2

the same way a 2 engine plane flies.

Answer 3

The old Ford Tri-Motor was one of the first three-engined planes to be successful, and was used for many years in the 1930's and 40's. The modern three-engine jets, like the Ford, have the third engine in line with the body of the plane. This makes the thrust perfectly balanced. There could be an imbalance in the torque if all three engines' blades or turbine fans rotate in the same direction, but this can be compensated fairly easily because of the great difference in mass between the engine blades/fans and the aircraft itself. Such compensation would be done with the wing flaps.

As an illustration of torque balancing, consider the helicopter. The imbalance in torque caused by the blades rotating in one direction (which tends to cause the 'copter body to rotate in the opposite direction) is counterbalanced by a small set of blades in the fan at the rear of the aircraft. It can do this because of two things: the mass of the 'copter is far greater than that of the blades, and placing it at the rear/tail of the 'copter gives it a great deal of leverage, making it more effective.

Answer 4

If you're talking about turbojet or turbofan engines, the direction of rotation has little if any effect. The thrust from the exhaust nozzles are not spinning even though the turbine and fan shafts are. They all rotate in the same direction.

Answer 5

The thrust of an engine is not dependent on the direction of engine's spin.

Besides (pilots, correct me if I am wrong) I believe all jet engines (of the same airplane) turn in the same direction.

Answer 6

Its still about the same amount of thrust on both sides, no matter which way the engines are spinning. The airplane might have a little bit of a left or right turning tendency, but nothing that would make the airplane unable to fly.Even when all the engines one side of an airplane fail, the pilot can still fly it down to a landing.

Answer 7

Well if you're talking about a jet engine, there's no torque to speak of. Well there is SOME obviously generated by the rotating compressors, but none that affects the aircraft's flight characteristics. Torque for prop aircraft is created by centriputal force/gyroscopic effect of the propellers; in rotary engine aircraft, where the engine itself rotated that mass created a gyro effect. Contra-rotating propellers were a relative rarity until after WW2 (though the P38 was a notable exception).

Answer 8

All the engines turn in the same direction. There is no variation in direction.

Answer 9

Jet engines have two spools inside that rotate in opposite directions and speeds.