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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]
ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.