|
|
Mike,
I have not read the particular article you cited (no time) but I am
familiar with Bob's position on the this subject. He correctly asserts
that most properly designed modern avionics should not get harmed by
being on during engine start. The supposed "spikes" during engine
start that are so fatal to avionics are just myths.
That said, there is another issue that needs to be considered. If you
have additional loads active while you are cranking the engine, you
putting additional strain on the battery. Is the additional strain
from having a simple engine monitor significant? Most probably not.
Is the additional strain from turning on the entire avionics stack,
pitot heat, position lights, strobe and landing light significant?
Absolutely. The threshold of what is acceptable lies somewhere between
the two extremes and I can not tell you where that is. It is a
decision that you need to make, both as the designer and as the pilot.
The second issue is whether the avionics are "properly designed." The
avionics that we can install in experimental birds do not have to meet
DO-160 and many (most?) will not survive the over-voltage and possibly
the under-voltage tests. DO-160 requirements, compiled by the private
firm RTCA and not the FAA, are not there because some FAA bureaucrat
had a fight with his mistress and decided to take it out on the
aviation community by coming up with some unreasonable requirements.
These requirements are there because it has been shown, either
analytically or anecdotally, that those conditions can and do exist in
real life. It is up to you, as a manufacturer, what level of testing,
if any, you want done on the electronics that go in your airplane.
Regards,
Hamid
MikeEasley@aol.com wrote:
Most of us need to have some avionics turned on for engine
starting so we have our engine monitor up a running for initial oil
pressure readings, etc. Bob Nuckols at the Aeroelectric Connection has
some very strong opinions on avionics during engine start.
Mike Easley
|
|