Path: utzoo!utgpu!watmath!clyde!att!ihlpb!rjungcla
From: rjungcla@ihlpb.ATT.COM (R. M. Jungclas)
Newsgroups: sci.space
Subject: Re: Model Rocketry
Summary: Questions answered
Message-ID: <9519@ihlpb.ATT.COM>
Date: 2 Feb 89 15:41:15 GMT
References: <9483@ihlpb.ATT.COM> <14081@cup.portal.com>
Organization: AT&T Bell Labs - Naperville, IL.
Lines: 56

>Since you can't legally build your own amateur engines, I'm wondering
>about the other parts of the bird.  Is it okay to build your own housing
>for a engine?  Can you do experiments with maneuvering and guidance?

Yes, you are free to experiment with other parts of the birds including
maneuvering and guidance if you stay within the applicable (model vs. 
high power) safety codes. The limits to be concerned about are 
"non-metallic" structural parts and any weight limits. I had a
friend who routinely "manufactures" his own fiberglass and carbon
filament tubes (BTW not an inexpensive proposition.)

>Let's say I build a rocket with an infrared quadrant detector linked
>to movable surfaces.  If I use Estes engines and go somewhere legal for
>conventional rockets, would I be breaking any laws if I launched a rocket,
>and then shot it down with a second rocket (assume no explosive in warhead,
>just kinetic energy)?

As long as you operated the vehicles within the prescribed safety code, 
this would be LEGAL.  I would urge you to present this in a slightly
different way to avoid the negative image that "shot it down"
conveys.  In particular, I would present this as a "dynamic mating
or tagging of vehicles."  BTW, I quote from the G. Harry Stine's 
safety report that the study of potential weapon use of model rocket
components "tended to substantiate the US Army Ordnance data on the
Loki rocket and indicates that the probability of a model rocket
hitting a designated target is infinitesimally small - on chance in
14 billion for each launch with a 95% confidence level."

>If I added rockets to a conventional R/C model airplane, for example to
>assist takeoff, would that be considered a model rocket or what?

Good question since it sent me back to the technical definition of what
is a model rocket. A rocket assisted conventional R/C model airplane is 
NOT a model rocket. If this model airplane meets all other provisions 
(construction, weight etc.) for the definition of "model rocket," the 
provision under which the above case would fail to satisfy the 
definition would be "Its model rocket motor is ignited ... meeting
the safety standard established by the NFPA/NAR/HIA."  The NAR/HIA
safety code requires all model rockets be launched within 30 degrees
from vertical. Hence any conventional R/C model airplane requiring
a horizontal take-off would clearly not be a model rocket. Would a 
conventional R/C model airplane using a near vertical liftoff be
consider a model rocket? This is not as clear cut, but answer is
probably no under the same provision since a conventional R/C model
airplane is not designed (hence not safe) for a vertical takeoff.
This Friday (2/3/89) I should be seeing a NAR representative at our
club's meeting. I will discuss my comments presented here with him and
get his (and NAR's) view, and post any clarifications or corrections
to what I said above.

I would like to ask what the poster's intent for this last question.
Why do you want to view a rocket powered conventional R/C model
airplane as a model rocket?

R. Michael Jungclas                    UUCP:      att!ihlpb!rjungcla 
AT&T Bell Labs - Naperville, IL.       Internet:  rjungcla@ihlpb.att.com