Vibration Monitor (Hyde, Wanttaja?)

If you wait that long, you're probably more concerned if the chain that's
holding the motor to the firewall is going to break after the motor cuts
loose from the mounts. All too often, the vibrations start to pick up
seconds or miliseconds before a catastrophic failure.

To do such a health-monitoring function properly, you really want some
seeded fault data to characterize what a "bad" engine spectrum looks like.
How many engines do you want to sacrifice to get the data? You can
approach
it from the "anything different from a healthy engine signature"
standpoint,
but that will likely result in a ton of false positive fault indications.


Are you suggesting that a bad engine will give clues to it's demise enough
in advance that you could actually do something about it? Clues that a
monitor could pick up on, but an experienced pilot wouldn't?

Of course. It has been done. Depends on the failure mode, of course. There
are some failure modes that take a long time to develop that give early
indications, and some that don't. A ton of work has been done in this area
for military jet engines. Seeded fault test data is the key to this.
Unfortunately, that might mean wrecking a bunch of engines to get the data.
It's not a project for the average home-builder.

Personally, I wouldn't bother trying to get a vibration caution together for
a home-built. Doing right would be just way too expensive. It would be
cheaper to just buy something that's turbine-powered and get rid of the
hazards that way. Besides, a huge number of failure modes already show up in
CHT's, EGT's, RPMs, etc. You have to weigh the cost of covering additional
failure modes against the hazards. This is really a job for engine
manufacturers. Additionally, you have to take complexity and reliability of
the sensing and processing into account. A monitor that is always going
haywire on you would be worse than nothing at all.

I'm actually looking at some stuff like this for possible inclusion on a
future project right now for a different type of powerplant. If you can
reliably predict RUL (remaining usable life) for a critical component, it
could be possible to reduce the amount of redundancy in a complex system and
rely on health monitoring functions to let you know when it's time to
replace the part.

PHM (prognostics and health management) has been a big focus in the military
aircraft world in recent years. I'm hoping that some of this technology will
trickle down to us in the GA world. Hmm...maybe I should get with an engine
manufacturer and work something out... SO, how much would people pay for an
engine health monitoring system package as an option for a new engine (i.e.
one of the new generation...maybe a DeltaHawk)? My guess is that it would be
too expensive to ever sell.

Pete


"LCT Paintball" wrote in message
news:ipA0e.102105$Ze3.20828@attbi_s51...
Are you suggesting that a bad engine will give clues to it's demise enough
in advance that you could actually do something about it? Clues that a
monitor could pick up on, but an experienced pilot wouldn't?

Are you suggesting that a bad engine will give clues to it's demise enough
in advance that you could actually do something about it? Clues that a
monitor could pick up on, but an experienced pilot wouldn't?


My company makes ~200MM/yr on this premies.

Adam
N7966L
Beech Super III