X-Mozilla-Keys:
A modern Fadec system
Forwarded by Archie Frangoudis
"First of all, I wish to thank Dave Pizza of GFW Maintenance for
arranging this meeting with Mr. Fred Martin, of ADLOG Publications,
the famous aircraft record keeping system.
Mr. Martin flew his 172K from 21N to ASH on October 29th to allow
first hand
observation of this endeavor, which is a co-operative effort of
Mattituck Air Base, and Aerosance.
A fresh 0-320, overhauled by Mattituck Airbase, was installed and
fitted with the Aerosance modifications, and after a few hours of
local flight, flew to OSH for “Airventure 99”.
This FADEC (Full Authority Digital Engine Control) system uses modern
technology previously unused on aviation piston engines. (remember
the PFM?)
The FADEC system began in the automotive industry where it is well
proven, airlines and the military incorporate it on turbine powered
aircraft.
At first glance, I noticed that the bulky, heavy mags were missing,
the spidered
injector nozzles were fitted with wires, ala automotive, and HEY!
WHAT”S THIS?
a carburetor also? How can this be?
Upon further investigation, no fuel line to the carb is seen.
Well, rather than re-invent the wheel by designing an air throttle
body, the carb is gutted, and utilized as an air control. This also
eliminates intake redesign, keeping
costs minimal. “KISS”.
What about ice in the venturi. Can the venturi be removed?
The system consists of two small boxes, each of which contains two
computers, a harness, sensors, fuel injectors, and an annunciator
panel. Each computer controls one cylinder, and serves as a backup for
a second cylinder, providing a fail-safe mode.
The computers calculate optimum pulses for the injectors and ignition
timing based on speed, pressure, temperature, and piston TDC location
in each cylinder.
When the engine is started, the computers calculate engine temp,
primes the cylinders, and adjusts the mixture according to the above,
including throttle position and altitude changes. At cruise, changes
are constantly monitored and adjusted for fuel flow, spark advance,
(or retard), individually in each cylinder.
This is done through feedback on EGT, CHT, fuel pressure, manifold
pressure, manifold temperature, and RPM.
The annunciator panel in the cockpit indicates high or low temp & oil
pressure, a
channel loss to a cylinder, fuel pump failure, or power source
failure. Also incorporated is a data port for downloading all
monitored profiles @ every .5 second for diagnostic profiles and
computer performance.
Total weight increase for the aircraft is approximately 14 lbs,
largely due to the use
of a backup power source- small, secondary battery.
With final testing, and FAA certification, sales and installations
could begin in the
spring, 2000.
In summation: A first step in updating 80-year-old technology.
Fuel consumption improved up to 15%
Tests indicate a 10 horsepower increase
No magnetos
No manual mixture control needed.
No manual primer needed.
System redundancy
No carb heat required.
Smoother running.
In a hypothetical devil’s advocate question to Mr. Martin:
“What will happen if you do not receive FAA approval?”
“We will have to revert to a carb and magnetos, but I would
not look forward to it”
OK, now the question on everyone’s mind: How much?
Current projected cost is around $4000. minus installation.
(and could possibly be less)
Not bad at overhaul time, just deduct the cost of mags and
carb or injector overhaul, and it becomes very attractive.
These guys are acting like they invented this stuff.
EAA and Mr. Martin meet Tracy Crook and Steve Parkman
(deceased). Sheeesss!
BTW where is the prop control?
I hate this kind of EAA PR crap! Where the heck have they
been for the last couple of years? On the moon?
PL
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