Tim,
I've sent the report to somebody who is German en fluently in English,
on his offer to translate. This translation takes an incredible amount
of time obviously.
But, as a matter of fact, the investigator thanks me for diverting from
my line of descent into an occupied office building to trees. The
wreckage was badly burnt. He also reports that he had Woodcomp check the
remains of the propellor, and that they stated that the blades "must
have been at a flyable angle" Also there was no obvious fault with the
engine. It has not been possible to determine what the cause of the
accident was. You may doubt of course that i have summarized properly as
well.
Significant might be also that after the accident Rotax was the first to
talk to me, smartavionics next, the factory was very interested also.
But no question, no word from Woodcomp.
I find it strange that you start an argument by telling us that you are
not an expert. And reach a conclusion, which is false. I am an expert,
electricity, electronics have been my profession and hobby. I know
microswitches and diodes, and if i tell you they are grossly underrated
and not up wet conditions, you can take my word for it.
My only interest is to save your lives. If you don't want it, please let
me know.
So, let me explain how the prop ended in a non-flyable position, so
simple that a non-expert can understand. I commanded via the controller
to go finer. That makes the motor run the blades to fine. The motor runs
then as long as the controller command it to go finer or the fine limit
switch cuts the current. In this case, because the desired rpm was high,
and i was climbing, the fine limit switch should cut in. But it didn't
because it was burnt, and short circuited to earth. The controller
reversed it voltage to increase pitch and we had a short circuit on the
plus now. The circuitbreaker popped. The revs went to 6200, with no
pull. Attempting to reset it booted the controller. Which proved it was
still working, And after the boot it popped again, The accident
conditions were there, low on altitude, low on speed.
I find it amazing that people defend such a product. Everybody i spoke
to privatly admids there have been problems with communication, with
quality of parts, with forgotten or loose parts, splitting blades,
whatever. Oh, of course, they will cut the blades in a banana form, or
apple, or anything else you fancy as fast. Very flexible indeed.
There is a good working product available, has been for years, factory
choice, with only plusses but the price.
Everybody makes a mistake, and i can admit it was my mistake to go on
the cheap and settle for a Woodcomp.
Regards,
Jos
27.6.2011 0:25, houlihan kirjoitti:
> Hi
> Further to Jos's comments about his very serious accident I seem to
> recall that the Austrian authorities planned to issue a report
> regarding the possible cause. I may have missed it so can anyone let
> me know what it contained, preferably in English.
> Not being an expert in these things I find I have problems linking the
> limit switch failure Jos talks about to the fact that for the
> propeller to go to fully fine or even beyond fully fine to a beta
> state requires the motor to be powered to drive it there. I am sure
> there may be a mechanism that will make that happen but I cannot see
> how it can do that just because a limit switch fails.
> Also my understanding is that Woodcomp do not support the Smartavioncs
> controller not surprising really as it is not their product and it is
> in competition with them but " banning" it is beyond their remit.
> Tim H
>
> On 26 June 2011 20:10, Jos Okhuijsen <josok-e@ukolo.fi
> <mailto:josok-e@ukolo.fi>> wrote:
>
> <josok-e@ukolo.fi>Hi <mailto:josok-e@ukolo.fi%3EHi>
>
> Sorry to remember you all that my Woodcomp prop nearly took my life.
>
> I hate to repeat my words, but memories seem to be short.
> The propeller i had was equipped with microswitches, which were
> and ,after a change, still are not designed for outside use.
> Nethertheless these switches are mounted on the backplate, open
> for weather.
> These switches are designed for AC 240 V, not for DC 12 V, and the
> Amp rating is way below the current going through them.
> The cross-over diodes are specified for less then half the current
> drawn.
> Even when activated only occasionally, it's a design flaw.
>
> Know to me are 3 incidents with short circuiting micro-switches,
> both other pilots could land their plane without damage to their
> plane or themselves. An incident with a loose gear, causing one
> of the blades at a totally diffent angle then the others was
> reported to me, and never made it to this forum. This seems to be
> the happy family show, which i am now spoiling. :-(
> It may well be that there are others, or people never fly in rain.
> or are just very lucky.
>
> In my case, to the best of my knowledge, a microswitch short
> circuited, taking the prop to a feather situation, shortly after
> take-off. I had been flying in heavy rain for hours the other day.
>
> Unless thing have changed is Jyrki the only one who understands
> English, if he's not available you are on your own.
>
> After my incident Woodcomp banned the Smart Avionic controller.
> What that means is unclear to me. As far as i know, they never got
> there own controller working decently.
>
> As for the figures, i've had trouble to keep up with a 912 with a
> fixed prop and i was flying with a 914 and a Woodcomp 3000. The
> only good figure seems to be the price.
>
> So in short: Save a few, risk your plane and life.
> The choice is yours....
>
> Regards,
>
> Jos Okhuijsen
> (enjoying his second life :-)
>
> . 26.6.2011 19:16, Frans Veldman kirjoitti:
>
> --> Europa-List message posted by: Frans
> Veldman<frans@privatepilots.nl <mailto:frans@privatepilots.nl>>
>
> On 06/26/2011 04:02 PM, Paul McAllister wrote:
>
> I was very impressed with the results that David Joyce got
> with his SR
> 3000W propeller from Woodcomp. I would like to some
> feedback from the
> forum about there after sales experience from Woodcomp.
> Please give me
> the 'good, the bad and the ugly'
>
> I got excellent support and advice when I was ordering the
> propeller
> from Woodcomp directly and delivery was prompt. After that I
> had no
> reason to contact them again as the prop works flawlessly and
> performs
> better than expected. Had to service it at 50 hours and did
> that at a
> local Woodcomp dealer. Found that one spinner screw was
> missing and got
> a complete new spinner fastening set free of charge. Ordered spare
> brushes, but at the 100 hour check I discovered that the
> brushes were
> almost like new and it looks like it is going to take a long while
> before I have to replace them.
>
> Have now 100+ hours but have had no issues with the prop.
> A few notes though:
> 1) I'm using the controller from Smart Avionics which is very
> configurable and able to match the prop exactly to the
> engine/airframe
> characteristics.
> 2) I have a prop with feather capability (to anticipate a
> potential
> future use of the glider wings). The props with feather
> capability have
> a stronger and faster motor. Maybe this is the reason why the
> Woodcomp
> prop behaves like a hydraulic prop and reacts so fast that it
> never
> allows the RPM to surge off its target.
>
> Hope this helps,
>
> Frans
>
>
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