Re: Airbus A310 question

Date:         22 Jul 99 23:30:27 
From:         Ernie Fidgeon <efidgeon@videon.wave.ca>
Organization: MBnet Networking Inc.
References:   1
Next article
View raw article
  or MIME structure

Jeff Bowen wrote:
> I noticed below each wing were three (I think it was three) "pods" which
> looked somewhat like solid canoes which each came to a flat edge at the rear
> where they protruded beyond the back edge of the wing.
>
> Does anyone know what the heck those "thingies" are?  I'm not an engineer or
> an aircraft expert, but am just curious.  Also, each of them had a metal tube
> sticking out the rear from that flat edge.  What were _those_?

You were looking at flap track fairings.  Under the wing trailing edge
resides the mechanical linkage that extends and deflects each flap,
typically two or more "tracks" per flap.  To reduce drag (and improve
aesthetics) a fairing is fitted around the track and linkage (canoe
fairing is a typical pseudonym!).  You may have noticed they deflected
as the flaps deployed, as they are linked to them so as to get out of
the way of the linkage and flaps as they change positions.

The metal tube you saw was likely the fuel jettison tube(s).  I'm not
sure how many the A310 have, but typically one per wing.  Each wing is
a fuel tank, and in the event of a landing required soon after takeoff,
the weight of the aircraft must be reduced to land safely (the maximum
landing weight is less than the maximum takeoff weight primarily because
of the vertical load limits on the gear and fuselage, and because the
approach speeds and landing run out distance are also limiting factors).
This is achieved by "dumping" fuel from the wing tanks.  No worries, the
system is grounded etc and the vapor disperses quickly with little
environmental impact.

Incidentally, the fairings are typically manufactured using graphite and
fiberglass composite materials.  These materials have favorable strength
to weight properties over metals, and they do not corrode or crack in
the same manner as metals.

Cheers
EF