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Posted

I like it. Certainly looks like my type of fun.

 

That is a lot of thrust to have up that high though.

 

Also you would have to be extra careful with passengers and bystanders with two props, most people will be used to one and I can see it wouldn't be hard to inadvertently end up cuddling the 'other' prop.

 

 

Posted

Yes please, nice machine, but with 2x 914 Rotax is not going to be cheap !

 

 

  • Agree 1
Posted

Is it just me, or did the performance seem not that great for 260hp?

 

680kg empty, 1134 gross.......

 

 

  • Agree 2
Posted

Impressive yes but as you say Downunder 260hp !, when I looked it up I was shocked at the specs being 2 X 914, you would have to wonder what the performance would be with 260 HP up front with only the one engine.

 

A question for the Aero dynamically gifted !

 

Would the front prop disturb the airflow so the rear prop would not be as efficient as if it had clean airflow ?

 

So two engines at the front would be more efficient than a "push me pull me" ?

 

 

Posted
Impressive yes but as you say Downunder 260hp !, when I looked it up I was shocked at the specs being 2 X 914, you would have to wonder what the performance would be with 260 HP up front with only the one engine. A question for the Aero dynamically gifted !

 

Would the front prop disturb the airflow so the rear prop would not be as efficient as if it had clean airflow ?

 

So two engines at the front would be more efficient than a "push me pull me" ?

It all depends ... but basically Yes, two at front on wing mounting is more efficient than push/pull

 

BUT while push/pull combinations are less efficient than traditional twins ... it's the lack of asymetric operations in single engine ops that is being accepted/traded as the benefit of the inefficiency

 

As to efficiency of fore or aft engine/props ... again it depends on what you are looking for and whats in front of or behind the props

 

eg the Cessna push/pulls are better flying on the rear engine than the front ... that shows that the drag of the high velocity front prop over the fuselage is a greater penalty than the inefficiency of having disturbed air from the same fuselage enter the rear prop.

 

With a traditional wing mounted twin the high velocity from the prop at front goes over the wing - not too much drag and the bonus is the higher lift - put the same engines behind the wing and it CAN be made very efficient but you have an engine and wing ahead of the prop disturbing the air into the prop ... and you do not get the extra lift ... but your engines and prop are further away from the pasengers eg the Piaggio Avanti

 

Horses for courses - aircraft design is a balance of SO many factors that no single solution is optimum ... hence we have hundreds of designs

 

Oh and for the specialists/nutcases who love flying wings, a propeller at the rear is ALWAYS better than a propeller at the front because the spinning prop out the back adds stability 'just like the tail that isn't there' when it is running whereas a front prop is an anti-tail group and you will need to add SO much more stability through sweep/twist etc to achieve a nice plane.

 

Cheers

 

 

  • Informative 1
Posted

I normally say that I have enough friends but Allan! I reckon I have room for one more

 

 

  • Agree 1
Posted

Ben87r you are the only one who wants to be my friend, I really appreciate that and will be shipping your new aircraft when I win the lotto.

 

I will keep in touch. 004_oh_yeah.gif.82b3078adb230b2d9519fd79c5873d7f.gif'

 

Alan.

 

 

  • Haha 1
Guest Maj Millard
Posted

Guernsey, Have I not always been friendly to you also ?...?...

 

 

Posted

Alan, I really appreciate your friendship, but may I please have a Spitfire when you win lotto, rather than something that looks like a hunchback dragonfly with big feet?

 

 

Guest Andys@coffs
Posted

And me too.....better win consecutive lotto's (unless it's the yank one) otherwise some might think there is a favouritism thing happening.....

 

 

Posted

Guernsey, I could be your new best friend as well - 3/4 Spitty would be just fine thanks. God speed with winning Lotto.

 

 

Posted
I normally say that I have enough friends but Allan! I reckon I have room for one more

You might look more sincere if you actually spelt his name right.

 

 

  • Agree 1
  • Haha 2
Posted

As for the plane, I enjoy watching STOL'ers and this thing just doesn't come up to scratch based on specs (relative).

 

I can't see that it does any more than a Zenith with half the power.

 

 

  • Agree 2
Posted

You would be better with one big engine. Having two and relying on both of them for steep climbs out of confined places gives you TWICE the chance of a failed engine ruining your day. The props would never be in Synch and that drives you mad after a short while. High thrustline makes a down load on the tail a certainty which reduces the payload possible and also trim changes with power change as well as the "normal" speed change. Nev

 

 

Posted

I like cool innovations and i LOVE STOL, but no thanks ...two engines in this config at that price...pass thanks...

 

Give me a STOL variation with big HP anyday in a single

 

Bloody hard to work on too

 

 

  • Agree 2
Posted
Bloody hard to work on too

Yup, that's a good point, when I went and had a look at Mike Sharples Avocet the thing that first struck me was the height of the engine and tail off the deck, over 3 meters - makes life darn hard.

 

 

Posted

You would need a mezzanine in your hanger , a scissor lift and then CASA would close you down for dangerous workshop practices..

 

Drop a spanner and its a 20 min climb down to pick it up

 

 

Posted

Stone the crows guys, looks like I may have to reduce my order because I may loose several friends if I give them one of these. 037_yikes.gif.f44636559f7f2c4c52637b7ff2322907.gif.

 

Alan.

 

 

Posted

What's the point? What's our LEGAL low level flight. USA and Canada may turn a blind eye to this sort of thing but Australia doesn't.....I hope. Yep, I agree it's fun but fly that plane at legal heights and it's boring.

 

 

  • Agree 1
Guest Andys@coffs
Posted

Well Im not so sure......our flight height limitation is excepted if landing or taking off and that is clearly what this guy is doing......of course there is the whole prior approval thing, unless you are the land owner and even if the river/bank is on your land Im not sure that rivers are technically yours.........

 

But I have to say that the incremental size in the smile you might have, to me, doesn't offset the serious extra $$$ required to achieve....

 

 

Posted
Is it just me, or did the performance seem not that great for 260hp?680kg empty, 1134 gross.......

260hp?

Most seem to have missed that 914's are only 115hp for 5 minutes...035_doh.gif.37538967d128bb0e6085e5fccd66c98b.gif

 

= 230hp.

 

Also, from a design view, he's probably loosing/absorbing 15~20hp countering the very high thrust line..?

 

A motor on each wing would give him even better performance, but at the cost/risk of an asymmetric engine failure.

 

Everything is a compromise.040_nerd.gif.a6a4f823734c8b20ed33654968aaa347.gif

 

 

  • Agree 1

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