Re: teeny vertical fins

Date:         13 Feb 97 01:37:40 
From:         "J. Heilig" <jheilig@gate.net>
Organization: Precision Scale Graphics
References:   1
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Scott Miloro wrote:
>
> I have noticed that a number of Boeing products have small (looks like 2 feet
> or so) vertical fins on the dorsal portion of the Fuselage.  I know for sure
> I saw these on a VA B747-200 at BOS.  Methinks they are on 757 type aircraft
> as well.  So the question is...what are these things, and what are they doing?

	I think you're seeing VHF sharkfin antennas.   All commercial airliners
have some sort of blade antennas for VHF comms on them, usually more
than one.  Most Boeing products (incl 707s) have them on the top and
bottom of the fuselage, in some cases (ie: 747) more than one on each
side).  AFAIK, there are no aerodynamic surfaces on a 747 other than the
vertical fin, horizontal fins, wings, and (in the case of the -400),
winglets.

Jennings Heilig