Message-ID: <19981022190334.755.qmail@www04.netaddress.usa.net>
Date: Thu, 22 Oct 1998 19:03:33
From: Dan Schaefer <dfschaefer@usa.net>
To: lancair.list@olsusa.com
Subject: thanks, grass strips, fuel vent ice
Mime-Version: 1.0

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First, thanks to all the nice folks who have messaged me re: my 
request for info about Oregon and Idaho (as a place to retire). 
Believe me, all the data is very helpful and very much appreciated!!

Skidding a IV on grass at power!!?? H---, I can't stop my 235 from 
sliding on concrete whenever I get over 2200 RPM or so, with the 
brakes on. I could probably take off of grass with my brakes on!!
(Hmmm, wait a minute, wait a minute, let me think that one over a
bit!)

To Bob Chesley re: plugging of the tank vents. I worried about that 
too and decided to provide an alternate vent source on the three 
tanks for the following reasons. Some years ago, I saw the results of a plugged vent in a spam can wing tank. The pilot apparently had to 
turn on the boost pump to get fuel to the engine - which, by the way,
had stopped until he did that - and by the time he landed, the 
aluminum was caved in between ribs pretty bad. I don't know what 
would have happened if he had to run much longer, either crush the 
wing completely, (they ARE quite flimsy, after all) or the vacuum 
might have eventually overpowered the pump and just stopped the flow.
Either way, it would have had an unfortunate result and I stuck that
in my back pocket for future reference.

Since I had installed the style of vents I described in the last post,
I have access to the short piece of tubing that connects the
tank to the little piece that sticks out in the slipstream with the 
45 degree cut. I tee'd into the vent lines there and installed small check valves with the outer end covered with several layers of 
cheese-cloth to keep the bugs out. These are positioned inside the stub wing (and cockpit for the header) just tied up out of the way of 
things. I used check-valves to preserve the slight positive pressure 
when things are normal (no ice or crud). The idea is for the valve to
provide an alternate vent in case the external vents are plugged, for
whatever reason. I don't even WANT to know what would happen to my 
wing tanks if the pumps were allowed to pull a significant vacum on
them!

I don't have the name of the company that makes these valves handy 
(it's at my hangar) but they are impervious to avgas (I use one of
their valve bodies for my over-flow sensor with the guts removed) for that reason, and they're fairly inexpensive, too. If any one's 
interested, I'll get the name of the company this weekend and post it
next week.

Cheers,

San Schaefer
N235SP


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