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External Measuring Devices On Aircraft

Tue Apr 13, 2004 9:59 pm

Can someone please give a word of explanation over the metal probe-like instruments seen sticking out of most aircraft fuselage at the front. They look like boomerangs sticking out. What are they called and what exactly are they measuring?
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RE: External Measuring Devices On Aircraft

Tue Apr 13, 2004 10:12 pm

It's called a Pitot tube and is used for measuring the airspeed of the aircraft.

For a very detailed explanation, I'd recommend taking a look at:
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RE: External Measuring Devices On Aircraft

Tue Apr 13, 2004 10:42 pm

For general reference, see:

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Photo © William Ronciere

The two large identical-looking probes that you see under the last cockpit side window are pitot probes/tubes, and combined with static ports elsewhere on the aircraft, comprise the main air data systems on the aircraft. This particular aircraft as two pitot-static systems installed (one is an AUXillary), thus two sets of probes, and the F/O's side will also have two. Each system uses two pitots, one on each side of the nose, The aircraft altimeters, and airspeed indicators are examples of items that utilize the aircraft pitot-static system. (Not an all-inclusive list).

The probe immediately to the left of the "G" in "Grand Union" is an angle of attack/AOA indicator, also known as an alpha vane. This probe is only on this side of the aircraft.

The probe immediately below the "n" in "Grand Union" is a temperature probe, and this probe is also only on this side of the aircraft.

[Edited 2004-04-13 15:50:11]
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