immediately becomes the big dog in the fight.
An electrical fire occurs either because
of a short, a bad component, or the use of
inappropriate wires used to carry an electrical
load.
Our systems are designed to take the biggest
electrical load to the buss and distribute it to the
many, many electrical devices on board through
a wiring system designed for the device. We
have breakers that range from 100 down to 1
or 2 Amps. As you go down in amperage, you
go down in wire gauge, or size. Doing this
saves weight. Using the entire aircraft as the
grounding buss also saves weight. Sometimes
a component will be exchanged for a better one
and the electrical demands are different. If the
wire and the breaker or fuse is inappropriate
for the demands of the new component, the
circuit could be overloaded. A breaker too
large (and this occurs when come one taps off
of a circuit, will allow too much power to a
wire that is too small. The wire will overheat
and not pop the breaker or fuse, and eventually
the insulation could melt exposing a bare wire
and creating smoke. Too large a wire cold
allow the new component to overload and fail.
There are myriad scenarios, but the gist is…
anyone changing anything electrically has to
perform or at least be aware of the electrical
load analysis.
Should you smell smoke and that funny
electrical smell, immediately turn off all
electrical power or at least anything that isn’t
vital to operation. No big deal if you are VFR.
Big Deal if you are in IMC.
A few years ago, six skydivers and pilot were
killed in a Cessna 206 that threw a rod in the
engine and caught fire. The incident occurred
just after the aircraft had departed on a jump
run and was climbing to altitude. The aircraft
threw the rod, and created a huge hole in
the crankcase and threw a cylinder. With a
mechanical pump for the Fuel Injectors, with
the prop turning, ergo the crankshaft and
camshaft operating, the pump continued to
provide fuel for all cylinders, including the one
that was gone. This fuel either hit the manifold
or was ignited by the thrashing of a number of
moving metal parts, and the fire erupted. The
airplane managed to make it to a nearby airport
and witnesses reported a ball of fire coming in
on final. The airplane touched down, veered
off of the runway and burned to the ground
with all souls perishing. This was a sad, sad
situation, as many of us knew the pilot and
some of the jumpers, one of whom was on her
training jump.
In hindsight there were a number of things
the pilot could have done, including having
everyone parachute to safety, but statistics had
proven that in the event of an event, it is much
safer for jumpers to remain in the aircraft, and
this was probably the guiding thought. For the
purposes of \