Ever fly a carb aircraft piston engine? Lots of mixture
adjustments are required. Most of the pilots successfully flying
them are not flight engineers.

The high quality ball valve shown has a one inch circumferential
travel. If you lengthened the lever to 3 inches, which
is a stock mixture control cable travel, fine adjustments are possible.
Mixture controls have vernier adjustments.

We have had several problems with EFI systems. There is a lot more
to fail. We had one total electrical failure crash that would not have
happened if they had a carb and mag. We had another in flight fire that
burned the wires going to the electrical fuel injectors causing
the engine to quit. Fortunately the guy was on short final.

I had a boost pump fail in a Mooney and the injection engine quit with a
bang.
Parts of the vanes made it to the mechanical pump and caused it
to fail. Fortunately I was over an airport and got it back on
the ground dead stick.

AN fuel plumbing is very reliable.

Dual alternators and batteries are heavy and costly.

My guess is the most reliable aircraft engine is the simplest and equipped
with carbs and magnetos not counting turbines. They are also
easy to maintain, inspect and fix by non computer gurus.

Paul Lamar ...No rotor no motor.

Paul,

These are very good arguments in favor of a simple carb and magneto.

For a magneto, perhaps a motorcycle-type setup could be fashioned, using
generating coils mounted around the flywheel. The coils are excited by
magnets permanently mounted in the flywheel. You could have a separate
set of coils for each spark plug, so you have the equivalent of dual
magnetos.

The Rotax magneto system is based on this architecture and works very
reliably. A third set of coils goes to a rectifier and provides charging
for the battery. So you don't even need a belt-driven alternator if your
power requirements are modest. If you need more power, just add an
alternator.

I think Revmaster also uses something like this. And some VW and Corvair
powered airplane builders use a similar setup with parts from a Harley
dynamo similarly mounted to the crankshaft.

With this magneto setup you will almost always have spark as long as
your engine is turning. You can't say that about an alternator system,
even if you have dual buses and alternators -- there are still possible
failure modes, with wiring, belts, control boxes, etc.



Regards,

Gordon.


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