Jos, I count you as a good friend but have to dispute many of your
statements. I also will state that I am no expert, but nevertheless am a
very interested amateur prepared to go to great lengths to get to the bottom
of something that affects my safety, ( and having said that Tim did spend a
lot of years as a radar/ electronics technician in the RAF). I have on the
other hand been a sort of unofficial (but unpaid I hasten to add) Woodcomp
agent in the UK having brought (and bought) the first Woodcomp prop into the
UK and then pursued the very lengthy process of getting it fully accepted by
the PFA.
As you know I was there at the accident, with the same plane and
the same controller and the same SR3000 (albeit without the reverse option).
I flew back to try to help you and subsequently examined the wreckage and
spent some time helping the Austrian AAIB man. As the accident happened
flying out of the Rotax Factory Flyin it's not surprising that they were
quickly able to help. Secondly since Mark Burton, owner of Smart
Avionics,was flying with us he was quick to talk to the investigator. I may
say that I gave the investigator my copies of the Smart Avionics controller
and SR3000 handbooks and allowed him to look at the complete workings of my
set up which was the official factory set up of an SR3000 without the
reverse option that you had and without the non Woodcomp/personal
simplifications to the wiring system that you had incorporated into the
circuitry. There wasn't too much left of the plane after the fire but the
prop hub was there and it was apparent that the blades were close to zero
pitch, so that regardless of how they got there it would be safe to say that
a similar accident could not happen with an SR3000 that does not have the
reverse option (which is not accepted by the LAA following your accident),
as the standard props have not only electronic stops at the fine limits but
also mechanical ones.
My understanding of the investigation was that no prime cause
could be positively identified, and if I do not misquote him I believe this
is also Mark Burton's view (who is also of course an electronics
professional.)
The microswitches have changed over the years largely to improve
their mechanical security but whether they are waterproof or not seems a bit
irrelevant. I have flown through prolonged rain and found no problems, and
you would expect that any water finding its way into a structure rotating at
2000+ rpm would very rapidly find its way out again. If you had parked the
plane under a waterfall and the spinner was full of water before start up
you might expect to notice problems when you switched on and went though the
recommended pitch change check.
You refer to the problem experienced by someone having some teeth
break on the gearing that determines the pitch angle of each blade and this
was promptly dealt with by Woodcomp replacing it both on new models and
retrospectively with a slightly heavier version of the gears. Woodcomp
certainly have no problem about the Smartavionics controller which is the
choice of the majority o f the substantial number of UK Woodcomp owners.
Apart from your problem I have not come across problems that were
not of the failsafe variety, and feel that describing the prop as a
deathtrap is entirely unwarranted
Regards and best wishes David, G-XSDJ
You mention
----- Original Message -----
From: "josok-e" <josok-e@ukolo.fi>
Sent: Sunday, June 26, 2011 11:46 PM
Subject: Re: Europa-List: Woodcomp after Sales Service
> 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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