Duc Flash

[JUSTNUZZA]

Wondering if anyone has installed a Duc Flash prop on their aircraft and what performance figures they are getting ? Just installed one on mine and would like to compare.

 

 

[jetjr]

I have experience with Duc and they are a very disreputable company, They refuse to refund despite me having returned prop to their factory. No longer communicating with me.

 

 

[JUSTNUZZA]

I have experience with Duc and they are a very disreputable company, They refuse to refund despite me having returned prop to their factory. No longer communicating with me.

What happened to your prop ?

 

 

[jetjr]

They were promoting at the time fitment to direct drive engines, confirmed fittment and suitability and long testing and experience.

 

Kit arrived, flange adapter incorrect, would not clear cowls, in addition surface of plated adapter had significant corrosion

 

After some time a new adapter was sent, also corroded, also didnt fit, third longer adapter purchased (not free), no credit to agent for initial 2 incorrect ones.

 

Prop fitted, poor performance, significant harmonic vibration at certain rpm

 

In addition promised long warranty was cancelled due to several prop failures on direct drive engines (prior to my purchase), prop had to be returned to factory regularly for inspection and use approval. Few I spoke to said their props had never returned from this process

 

Around then they ceased supporting Aus/NZ agent who was helping me.

 

Sent back entire assembly to France under "satisfaction guarantee" with pre approved refund. They refused to claim package from French customs, I paid and had package delivered to them, then they claimed 1 blade was damaged and offered 50% refund if I provided bank details and letters absolving them of liability.

 

Subsequently (some time and emails later) I agreed and communication stopped.

 

Started in 2011, last comms 2012

 

In complete contradiction, I then purchased Bolly prop, fitted, ran fine, rang them for advice with some small issues and they supplied new design 2 Blade prop and hub totally for free - "no need to return other one". Performance excellent.

 

 

[JUSTNUZZA]

They were promoting at the time fitment to direct drive engines, confirmed fittment and suitability and long testing and experience.Kit arrived, flange adapter incorrect, would not clear cowls, in addition surface of plated adapter had significant corrosion

After some time a new adapter was sent, also corroded, also didnt fit, third longer adapter purchased (not free), no credit to agent for initial 2 incorrect ones.

 

Prop fitted, poor performance, significant harmonic vibration at certain rpm

 

In addition promised long warranty was cancelled due to several prop failures on direct drive engines (prior to my purchase), prop had to be returned to factory regularly for inspection and use approval. Few I spoke to said their props had never returned from this process

 

Around then they ceased supporting Aus/NZ agent who was helping me.

 

Sent back entire assembly to France under "satisfaction guarantee" with pre approved refund. They refused to claim package from French customs, I paid and had package delivered to them, then they claimed 1 blade was damaged and offered 50% refund if I provided bank details and letters absolving them of liability.

 

Subsequently (some time and emails later) I agreed and communication stopped.

 

Started in 2011, last comms 2012

 

In complete contradiction, I then purchased Bolly prop, fitted, ran fine, rang them for advice with some small issues and they supplied new design 2 Blade prop and hub totally for free - "no need to return other one". Performance excellent.

I hope I have a better outcome than you then.

 

 

[jetjr]

Of course you should, just be aware of who your dealing with.

 

 

[JUSTNUZZA]

Anyway, Seem to get better performance figures now with my ground adjustable prop over my constant speed useless unit and a lot less to go wrong with it.

 

 

[facthunter]

You probably don't need a C/S unit unless your plane cruises above say 115 knots. There is extra weight, cost and complexity with one, but it should always perform better than any fixed (in flight) pitch prop. (All other things being equal) Any prop must be matched to the plane and the engine. Nev

 

 

[JUSTNUZZA]

The only real benefit of the C/S prop that I had was a slightly shorter take off roll and a steeper approach angle because of the prop being in full fine. Only used to get 118 IAS 5200 rpm at 2000ft and 1200 ft min climb at 2o litres an hour. Now 125 IAS 5200 rpm at 2000 ft and 1000 ft min climb at 19.5 litres an hour. The prop is quite unusual in that it decreases the engine RPM from static to dynamic by about 200 rpm (i.e. start take off roll 5200 rpm and by the time you rotate the RPM is 5000 RPM).

 

 

[facthunter]

There's obviously something wrong with your C/S prop. At your cruise speeds you are getting into the area of real benefit. I don't understand why you would get less prop revs when you have forward (flying) speed. with no pitch change. Nev

 

 

[JUSTNUZZA]

There was something wrong it was a Woodcomp SR-3000, no end of trouble with burnt out electric pitch motors and C/S controllers. Have not heard any good reports about them. As for the RPM drop with the DUC I guess it is to do with their constant speed effect claims.

 

 

[facthunter]

There are 2 forces on a prop trying to alter the pitch. One, the Aerodynamic Turning Moment tries to coarsen it. The centrifugal one fines it off as the revs increase Nev

 

 

[JUSTNUZZA]

From the operating manual.

 

 

[JUSTNUZZA]

From the operating manual.[ATTACH=full]30892[/ATTACH]

Sorry, did not upload very clearly.