View Single Post
  #9  
Old October 21st 03, 05:29 AM
Kyle Boatright
external usenet poster
 
Posts: n/a
Default


"Bart D. Hull" wrote in message
m...
Kyle,

What has been the experiences with the other members of
your EAA chapter with their "Certified" engines for this
last year?

Why did the first homebuilt engine quit?

I don't buy the second issue as an engine issue. If you
don't build anything right its gonna fail. I can't believe
that the airplane was above its gross weight with a single
pilot and a homebuilt engine.

I can buy the third issue. But what if it was a FADEC on a
Cont or a LYC instead? They quit without juice as well.

I'm not being argumentative, but want more details so my
auto-conversion will be more successful than a LYC or Cont
install.

Thanks
--
Bart D. Hull

Tempe, Arizona

Check
http://www.inficad.com/~bdhull/engine.html
for my Subaru Engine Conversion
Check http://www.inficad.com/~bdhull/fuselage.html
for Tango II I'm building.


Kyle Boatright wrote:


"My" EAA chapter has 3 members with Auto Conversion powered aircraft.

One
of them was totalled this spring when the engine failed. A second was
totalled this fall when the gear failed because the stock gear wasn't up

to
the task of hauling around all of the extra weight. The third aircraft

s
still flying, but has had at least two engine out experiences, both of

which
turned out to be problems keeping his engine's electronic brain-box

supplied
with electrons. In both cases the aircraft was close enough to an

airport
to make an uneventful dead stick landing.

Bottom line, your risks are significantly increased if you use an auto
conversion. Neither the engine or structure is designed with that

purpose in
mind, and the systems will (generally) be more complex than a Lyc or
Continental. Sure, it can be done properly, but more are done the

*wrong*
way than the right way.

KB


The first aircraft went down because the subaru ate a valve. There was some
talk in the chapter that the engine's oil temperatures were very high, but
the owner has never personally confirmed this in my presence. The gear
failure was related to *where* the weight was located - all of it was waaay
up front. The electrical problems on the third aircraft had to do with a
ground wire that had an intermittant connection which took out the brain
box. Obviously, with two ignition systems - particularly if at least is a
magneto, the chances of losing BOTH ignition systems is very small. The
chances of losing the *single* home baked ignition system is much higher.

Again, most folks don't have the ability, financial ability, or patience to
properly engineer an engine conversion that is up to Lycoming or Continental
standards. There are all sorts of NTSB cases which indicate this. I'm sure
it can be done, but at what price? 5-10 years and/or a million dollars in
development costs? To KNOW you've got the equivalent of a Lycoming or
Continental, that's what it would take...

This year's only *bad* chapter experience with a certified engine was a
fellow with a Continental 0-300 who wasn't happy with his compression
readings, so he pulled the cylinders and reseated the valves or something.
A non-event, as it was not a failure, and was dealt with on the ground.
That's one of the better things about certified engines. The engines and
systems are fairly robust, so most problems don't result in the fan
stopping.

KB