what (not) to use on fuel line fittings

[Garfield Willis]

On Mon, 29 May 2000 07:21:29 +1000, Peter Gargano
<peter at ntserver.techedge.com.au> wrote:

>More things to watch out for on fuel line fittings. Alas, there
>is little EFI content in this very interesting article, with an
>important message for engineers of both mechanical and software
>persuasions...
>
>  http://www.asktog.com/columns/027InterfacesThatKill.html

Pretty surprising from a press reporter; he almost got mostly everything
right. There are a couple things to point out, tho.

(1) Most all the Av guys figure "what really killed John Denver" was his
ignorant low-level flying in an airframe very new to him. Altho everyone
agrees the fuel selector was in a stupid place, there are MANY things
that can cause you to have to turn around and reach back, and as a
neophyte in this aircraft, push your foot on the right rudder pedal. The
REAL problem was he was flying WAY too low to allow for any margin of
any sort. Exhausting of fuel tanks in aircraft is often done routinely
in some setups (as weird as that might seem); you just have to make sure
it doesn't happen when you're 300ft AGL. Even if no unplanned manuever
had occurred, you can easily lose that much altitude getting the fuel
reselected following exhaustion. He was just TOO low; period. When you
fly that low over ANYTHING where you cannot set it down, you have to
understand you're in a very high risk mode; flying hundreds of feet over
the ocean may be dramatic site-seeing, but it's VERY risky. Not
something anyone with good sense does in a fairly new or unfamiliar
aircraft, and most would not risk at all.

(2) The author made no distinction between GA (general aviation) and XA
(experimental aviation), but Denver's LongEZ (as are all custom-built
airframes) was in the Experimental category. Just in case yous guys
care, General Aviation is a category of aircraft where factories are
certified to build the planes, ONLY certified A&Ps (airframe &
powerplant mechanics) can work on them, and there are tons of
regulations on having to use JUST the right repair part, etc. etc. It's
intended that people flying in this category can expect their airplanes
to be as safe and well-tested as any (albeit higher risk) consumer
product. In sum, it's a highly regulated INDUSTRY and product, aimed at
protecting the consumer.

Experimental Aviation is totally different, is assumed to be high-risk,
is for those willing to incure those risks in the pursuit of what these
days would/should be called an "extreme sport". Altho there are still
inspections and regulations governing experimental aviation, they are
WAY different in depth and purpose. In Experimental Aviation, you can
use auto engines, auto parts, non-AN hardware, experimental airfoils and
airframe configuration, etc, as long as you can convince the FAA
inspector that the craft is "airworthy", you are allowed to begin
experimenting inflight. There is always a "fly-off" period where you're
restricted near an airport, away from major population centers, etc. The
point being, the FAA's regulations on XA aren't intended to render these
aircraft a "safe & effective" consumer product that's unlikely to bite
unexpectedly.

The sad fact is that many seeking higher performance or perhaps
foolishly, lower building and maintenance costs, have mistakenly
gravitated to the sport, because it's possible to buy these aircraft
used, get checked out in them, and go off flying. That's what Denver
did. Unfortunately for him and music lovers, he apparently didn't
ratchet up his caution level sufficiently.

The main reason I mention all this is to take the opportunity to educate
on the basic differences between "General Aviation" (GA), and
"Experimental Aviation" (XA). Lumping them together as the reported did,
tends to give BOTH a bad name.

Orville and Wilbur Wright built what would still be considered today an
Experimental Aircraft. Cessna on the other hand builds GA aircraft.
Obviously we still need both types to allow for developers and
experimenters, as well as ordinary consumers. Bad when you confuse them
tho.

Gar

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