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From: bruce@logic.dsg.ti.com (Bruce Florman (BFLM))
Newsgroups: rec.skydiving
Subject: Re: bungee jump from plane
Message-ID: <1991Feb12.153333.18918@axis.dsg.ti.com>
Date: 12 Feb 91 15:33:33 GMT
References: <38P3w3w161w@grafted.UUCP>
Sender: news@axis.dsg.ti.com (System News Administ)
Organization: Texas Instruments, Austin, Tx.
Lines: 46

In article <38P3w3w161w@grafted.UUCP> dappel@grafted.UUCP (Dave Appel) writes:
>to: the genius who wants to bungee jump from a plane.
> 
>Uh, excuse me, but where did you leave your BRAIN?
> 
>Do you have any idea of the effects that vector forces have
>on an airplane?  Lift, drag, thrust, etc?  Have you ever
>noticed the pilot trying his darnedest to maintain straight
>and level flight with 4 or more skydivers hanging on the
>outside?  Usually causing the CG (center of gravity) to
>be outside of normal limits?
> 
>First off, connecting the bungee cord to any point other than
>the center of gravity is going to cause the plane to be unstable
>at best, or tumble out of the sky at worst.

Uh, I don't think so.  I suppose that in these modern times it may be
that nobody remembers them, but have you ever heard of a "jumper in
tow?"  It is a situation which arises when a static-line (remember
those?) fails to release a jumper due to entanglement or mis-rigging.
Although it is (was) something to be avoided, it is not generally
considered to be catastrophic to the airplane.  A bungee, because of its
elasticity would probably be even less stressful to the airplane than a
jumper in tow.

> [other complaints deleted]
>
>Maybe, just MAYBE, such a stunt would be possible from a C-130
>hercules, where the weight of one jumper would make only
>a very small difference in the CG.   But anything the size
>of a DC-3 or smaller would be courting disaster.

Well, I do know of one static-line jumper who managed to get his main
entangled with the tail wheel of a DC-3 (don't ask me how, I didn't see
the event itself, I just saw the plane landing with the main trailing
off the wheel).  Even with a whole slew of floaters, the CG on a DC-3 is
well ahead of the tail wheel, but the plane didn't crash or have any
other severe control problems.

I'm not the one who proposed bungee jumping from a plane, and I'm not
sufficiently impressed with the idea to expend much energy trying to
organize such a jump, but I think that your objections are largely
without basis.

--Bruce Florman
  D9019 (ret.) Blue Skies!