Twice in a the last few weeks , I have found engine driven
fuel pump drains with shipping caps installed.
It appears that mechanics/builders are not aware of the
importance of installing a drain in the dry bay between the engine driven fuel
pump and the accessory section of the engine.
Here is what is involved. If the seal were to fail in the
engine driven fuel pump--raw fuel would go into the dry bay, and if the drain
is capped, fuel will blow out the engine seal and go into the crank
case.
Imagine with me. There you are at 24,000 feet, you may notice
a slight drop in fuel flow, not much. Engine driven fuel pump pressure
will be directed toward the engine seal / blow it out and go directly into the
engine crank case. And oil will be diluted as it is contaminated with fuel.
After two or 3 gallons get into the crank case, how much
lubrication do you think that will be?
What if,-- it just happened to ignite as the crank case
overflows out into the turbos? Scary huh?
Here's a test. On your next preflight take two pieces of
masking tape, and write "manifold drain" on one and "engine driven fuel pump"
on the other. Get underneath your cowling and put the tape against the drain
line that you believe to match the name on the tape.
Take the cowling off. Make sure that these two critical lines
are properly identified--and installed--and DRY.
ANY fuel and out of either of these lines and you should not
fly under any circumstances.
If fuel leaks through the manifold valve diaphragm, the engine
may continue, repeat MAY, continue to run for several minutes with electric
fuel pump on high. But if the diaphragm is split--eventually even high boost
will not hold the valve open in the engine will stop.
We are so used to seeing fuel drain from the bottom of the
cowling from the sniffle valve--that we ignore these other two drains which
are critical.