Monday, February 18, 2013

Things you might see on a jet (not counting gremlins on the wing)

citation xEveryone is familiar with the basic parts of an airplane. Wings, tail and fuselage are easily recognizable as are propellers and jet engines. A modern jet aircraft contains many other parts that are not so well known.


flapsFlaps are a moveable section on the rear of the wing that are used for both takeoff and landing. They droop down to change the shape of the wing. This allows the airplane to fly slower without approaching its stall speed. Flaps can be found on many small general aviation aircraft as well as the largest transport airplanes.

flaps2Underside of the flaps showing the runners which guide them into place. Flaps can be moved to several different positions. Landings are usually made with full flaps and takeoffs are made with a partial flap setting.


slatsSlats are similar to flaps, but are found on the leading edge of the wing. They are typically found only on larger high performance jet aircraft. Like flaps, slats allow the airplane to fly slower without stalling. They are used primarily for takeoff and landing and are retracted during cruise flight.

slats3Forward view of the slats. The slats run along the leading edge of the wing and are normally deployed for takeoff and landing. The inboard section of the wing is not movable.

slats2This is a view of the underside of the deployed slat. The slat can be heated with air from the engines to prevent ice buildup. This is accomplished through the duct in the foreground.


wingletWinglets are curved up devices on the wingtips of many new jet aircraft. They reduce drag by helping to reduce the turbulent air left as the wing generates lift. Winglets also have the effect of adding length to the wing without requiring additional strengthening. This additional lift translates into fuel savings and longer flight ranges.

Static wicks

wicksStatic wicks are protruding wire-like devices that stick out from the trailing edge of the wing. They help to dissipate the static electricity that builds up on an airplane as it flies. The wicks also help to protect the airplane from the electricity of a lightning strike.

Spoilers and speed brakes

spoilerSpoilers and speed brakes are rectangular plates on the upper surface of the wing. As their name suggests, they spoil the lift being produced by the wing. Spoilers are used to slow the airplane quickly and can be deployed both in the air and on the ground.

Pitot tubes

2013-02-03 12.40.47A pitot tube provides the airplane’s instruments with information that allows the plane’s airspeed to be calculated. The tube takes a sample of the ram air pressure and compares it to the static pressure of undisturbed air. The difference is the plane’s speed through the air.

Pitot tubes can be mounted on the fuselage or the wing, but on most jet aircraft they are mounted on the nose section of the fuselage. Most jets have three pitot tubes, one for each air data system (one for each pilot plus a standby).

AOA and Temperature probes

angle of attackOther probes on the airplane include sensors for angle of attack and temperature. The upper sensor is the angle of attack probe, which determines the difference between the where the wing is pointed and the air moving over the wing. This is important because exceeding the critical angle of attack causes the wing to stall or stop producing lift.

Temperature probes are used to determine the outside air temperature. Temperature is used by the air data computers to determine speeds and performance. It also helps the pilots to determine when it is necessary to activate the airplane’s anti-ice systems.


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