Re: T-Tailed aircraft

From:         Tony Maddern <>
Organization: University of New South Wales
Date:         27 May 96 13:35:38 
References:   1
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Doug Snow wrote:

> I always thought that ( The "probe" on the top of the 707 fin) was a pitot tube!

I blew the cobwebs of my 707 Operations Manual and the probe is the HF
antenna which is shared by the 2 HF systems via an antenna coupler
which tuned the antenna length to the frequency on the selected radio.
If both radios are keyed nearly simultaneously it is possible to jam
the coupler and lose both radios. There is a can shaped pitot lower
down on the fin which is the sensor for the rudder Q-feel.

Tony Maddern ex-Captain & TRE, IRE, B707, L1011, B747-200/300/400