An engine failure on short final will not allow any time to reboot, change
programs, etc. Multiple computers running multiple systems brings with it
the need to identify the failed system, make adjustments to keep flying,
and then try to get it started again. This is why they require multi engine
training. A twin is just a bigger plane, but with more systems to manage.
More systems + emergency = bad. The moniker KISS applies to an aircraft
probably moreso than it does most other places in life.

IMHO, the system needs to be able to:
1. Run the engine
2. Monitor itself and be able to handle everything but catastrophic
failures.
3. Be completely redundant.
4. Notify the pilot of any issues.

Lets go to the Hercules ARM chip that I mentioned a while back. It was
designed specifically for life critical systems. It has dual CPUs working
in lockstep and checking each others output continually. All on one board.
There are 40 I/O ports. One could use dual sensors to input different ports
on the board read by each side of the CPU and have a redundant system on
one board. If you were to go a step further, you could use dual boards and
the dual sensors for a totally redundant system. It would require the
appropriate code to be able to identify an anomaly and then handle it which
is where the additional many many lines of code come in.

I am designing my system like the above. I want the system to run, to check
itself, to let me know if something is wrong, and to compensate for it.
Then it has to let me make some manual adjustments without much hassle
while I try to find a suitable landing spot.

As pilots we all know that if our computer or engine starts to act up, we
aren't going to reprogram it inflight, we are going to look for a landing
spot NOW. An engine or system failure in IFR is worse, much higher pilot
workload and much more at risk.

A computer controlled EFI is not about saving a few pennies on fuel, its
about an improved aircraft with modern automation that monitors and
continually adjusts the engine and notifies the pilot if something is
amiss. My Lycoming mechanical FI works just fine even if its not totally
efficient with its manually managed fuel ratios. But, its simple, its as
smart as the pilot, and it works.

My flap deployment system is based on the Atmel chip on a tiny board. It
monitors where the flaps are, airspeed, and how much current it takes to
put them down. Push the button once, you get 10 deg, again and you get 20,
again and you get full 40. But, you cant get the 10 unless your airspeed is
below my 110 knot deploy speed. Full throttle means the flaps come up
slowly as airspeed builds so during a missed approach I dont have to worry
with it. All fully automated, no mechanical parts except the flap motor.
And for a backup I have a DPDT switch that overrides the computer and lets
me do what I need to do. Easy, redundant, and functional. KISS.

My rotary engine will have this EFI, and a mechanical FI copy from a
certified plane as a backup. If I go up, I am coming back.

Kevin Alderman

It can happen to any engine and any fuel system.
Learn to slip. I do not know why that curriculum is not on
the FAA private pilot training.

I ALWAYS ALWAYS SLIP!!!! it in. Altitude is your best friend.

That way you can land dead stick no matter what.
We had a well known ATP have an certified engine failure on SZP final as he was dragging
it in on the 3 degree glide slope. Landed on the free way and took the top
off a Honda. Serious injuries but fortunately no fatalities.

Paul Lamar


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