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Posting-Version: version B 2.10.2 9/5/84; site magic.ARPA
Path: utzoo!linus!decvax!decwrl!magic!price
From: price@magic.ARPA
Newsgroups: net.aviation
Subject: Re: heresay about ultralights
Message-ID: <169@magic.ARPA>
Date: Fri, 19-Jul-85 19:44:42 EDT
Article-I.D.: magic.169
Posted: Fri Jul 19 19:44:42 1985
Date-Received: Sun, 21-Jul-85 23:42:56 EDT
References: <812@vax2.fluke.UUCP> <815@ihnp4.UUCP>
Reply-To: price@magic.UUCP (Chuck Price)
Distribution: net
Organization: DEC Systems Research, Palo Alto
Lines: 49
Summary: 

In article <815@ihnp4.UUCP> cfiaime@ihnp4.UUCP (Jeff Williams) writes:

>The quality of the hardware used, the quality of the cables used, and the 
>overall structural integrity seems to be poor.  The 5 or 6 that I 
>looked at closely at Oshkosh last year were better than the early ones,
>but still were lacking.  

Most ultralights use aircraft quality hardware. Some don't. Most have
single points of failure scattered through the airframe. With proper
inspection and a parachute, this problem is minimized.

>One other concern is of the covering material.  A lot of these machines
>use rip-stop nylon sail cloth for wing cover.  When new, it is quite
>strong.  However, I have seen very few of these machines that used
>any type of protection against ultraviolot  rays (i.e. doping the
>fabric).  And there is no requirement to "annual" the machine.  How many
>people are flying with unsafe covering?  According to the Stitts
>people (aircraft fabric manufacturers), undoped fabric may deteriorate
>to unsafe levels in a matter of MONTHS if unprotected.

Hang gliders have used rip-stop nylon for years without a single accident
attributable to sail cloth deterioration. The material bears about 1.5
lbs/sq ft on a hang glider, and 3 lbs/sq ft on an ultralight. This is
reletively light loading. I think sail-cloth induced failures will be
few and far between, if they happen at all. BUT: This does not eliminate
the need for sail inspection, because when the argueing is over, it
is still a fact that UV DOES deteriorate rip-stop nylon eventually.

>After all is said and done, make mine an airplane, with the requirements
>for annuals, TSOed parts, and the whole bit.
>
>				jeff williams
>				AT&T Bell Laboratories
>				ihnp4!cfiaime


To each his own. Some people, sitting in their overstuffed chairs in
their safe living rooms would call all of us crazy.

And anyone who waits a whole year to inspect their ultralight is crazy. That
is the one great advantage to most ultralights. They can be EASILY inspected.
Anyone who doesn't inspect frequently is playing Russian Roulette with
5 bullets.


See you at cloudbase!

-chuck price
decwrl!price