Message-ID: <20000810185006.28754.qmail@web122.yahoomail.com>
Date: Thu, 10 Aug 2000 11:50:06 -0700 (PDT)
From: BILL HANNAHAN <wfhannahan@yahoo.com>
Subject: emergency battery iso,  convention tips
To: MAIL LANCAIR <lancair.list@olsusa.com>
Reply-To: lancair.list@olsusa.com
Mime-Version: 1.0

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 Being a simple VFR pilot I am overwhelmed by all
this talk of emergency battery busses, isolation
diodes, relays, etc.  What you need is some kind
of super high-tech device that will allow a
modest float charge with  minimal voltage drop
while limiting reverse current flow when the main
battery voltage goes to zero,  something that
will warn of the failure and protect the backup
battery from overvoltage conditions, and isolate
it under extreme conditions.

Hey, wait a minute, didn’t that Edison guy invent
something like that? Actual measurements of a 15
watt 12 volt bulb recorded a current of 1.0 amp
at 12.8 volts for an effective resistance of 12.8
ohms. At 0.4 volts the cold filament conducted a
quarter amp for an effective resistance of  1.6
ohms. 

Such a device could provide the float current for
a small emergency battery. If the main battery
voltage goes to zero the bulb will limit the
discharge current to 1 amp, mount the bulb on the
panel and it will light up to  warn you of the
discharge. If you are a long way from VFR
conditions and need every milliamp hour, remove
the bulb to isolate the backup battery.  

In an overvoltage situation it will limit the
emergency battery charging current to 1 amp or
less. In an extreme overvoltage condition the
filament will melt isolating the emergency
battery, and indicating the problem to you via
the “flashbulb” effect. Not bad for a
lightweight, simple, fifty-cent part.

Here are some convention suggestions from a
letter I sent Tom a few years ago.

The convention starts on a Saturday and goes for
nine days.  The first weekend is dedicated to
sport aviation.  The second weekend will be
dedicated to warbirds.  The mix will transition
from sport aviation to warbirds as the week goes
on. There are several advantages to this
approach.

1	The big weekend crowds will be split into two
weekends reducing the strain on facilities.  

2	Sport aviation enthusiasts can pursue their
interests in a more relaxed environment without
the pressure of the warbird enthusiasts with
their cameras, chairs and binoculars banging
against our canopies.  There will be more time
for fun flying and flybys.  Noise levels will be
lower for the first half of the week when most
forums will be scheduled.

3	Warbird enthusiasts can have an entire weekend
devoted to both old and new military aircraft. 
There is a general consensus that the big iron is
what draws the public providing the cash cow that
helps finance the EAA budget.  This is often used
to justify the provision of free gas for the
warbirds.  By separating sport aviation and
warbird aviation this theory can be put to the
test, and if it proves to be accurate the
opposition to this practice can be largely
eliminated by reducing ticket costs during the
first six days of the convention and raising fees
for the warbird weekend. The total attendance and
cash revenue can be increased beyond the levels
generated by one big weekend and the warbird
enthusiasts will be paying for warbird gas.

4	Splitting the emphasis over two weekends will
help alleviate the parking problem that has
developed in the homebuilt/warbird parking area. 
A suggested solution is as follows: Go to the
fence separating the warbird parking from
homebuilt parking.  Move 100 yards north and
install a fence.  Move 100 yards south and
install another fence, then put up a sign
indicating that the space between the two fences
will be available for homebuilt parking till
Wednesday noon, and will be used for warbirds
after that.  Homebuilt pilots planning to leave
by midweek can park there, making that prime
space serve twice as many aircraft as it normally
would during the course of the show.

5	With the existing schedule many people arrive
several days early to get a parking space and
enjoy the more relaxed pre convention ambiance. 
Although the new schedule will be officially
extended by two days, the actual demands on
security and volunteer personnel will be modestly
increased due to a reduction of early arrivals
and reduced peak crowd size.

6	Since nine days are too much for one crew to
work, develop two crews that each work 4  or 5
days. That way each crewmember will have some
time off to enjoy the show, making it easier to
recruit new volunteers.


7	Provide more diversity in food service,
particularly a selection of healthier food for
people who would like to keep their medical
certificates.  Junk food is OK for one day  but
it gets old fast.  Baked potatoes, corn on the
cob, fresh fruit, vegetables, bread, beer, wine
and a first class salad bar sold by the ounce
would be a big improvement.  


8	Cancel the yodeler on the P.A. system at 7 AM
each morning and replace him with a comprehensive
24-hour national weather forecast. At least add
the forecast.

=====
BILL HANNAHAN
WFHANNAHAN@YAHOO.COM

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