SixZ

[SteveWrightNZ]

Originally Posted by David Staten

Of course, reality is.. you would only be at that power setting during takeoff and climb.. and have to throttle back significantly during cruise to keep the speed UNDER VNE in level flight.

I read somewhere that the Cozy VNE was set in some arbitrary fashion. If relevant components were upgraded it seems to me that this VNE could be raised, viz Berkut. I actually enjoy flying my X-Plane Cozy throttled right back, humming along at 120kts. I bet its idyllic in a real Cozy doing that.

S

[Kumaros]

A logical upgrade of my Cozy III would be a Cozy MkVI
Two in the front and four in the back in lounge seating, with the two rearmost seats more fit for children or small persons. The engine to be one Mercedes Benz V6 turbodiesel, 225HP in standard form, chipped to ~250HP just for take-off and initial climb.
Kumaros
It's all Greek to me

[ShaleDC]

And built out of unobtainium?

[Kumaros]

The consensus seems to be that a Cozy MkVI would need to be roughly 25% bigger and more powerful than a MkIV.
I'm proposing a Spartan Cozy, 25% bigger wings, otherwise standard materials, standard construction, slightly higher and 2 feet longer fuselage, allowing lounge seating in the back with interweaving legs and more upright seating as per Wapati8 drawings, luggage storage between the backs of the front and the clapping first row of back seats, spar between second and third row of seats, could be used as a tabletop for notebooks etc., diesel engine offering about 30% fuel efficiency advantage thus obviating the need for more fuel. Five blade Ivo Magnum in-flight adjustable prop. Extra cost over a standard Cozy? no more than 25%. Nothing revolutionary, just evolutionary.
Kumaros
It's all Greek to me

[Leon]

and also a very cool Idea ! Although, maybe a little wider Fuse would be a nice feat, also giving you the possibility of a twin engien coaxial (leon brothers) variant. still my dream, that.

[Kumaros]

My rationale for the seating arrangement and spar location:
Pilot and co-pilot up front balance the heavier engine, passengers and fuel tanks are arranged around the center of gravity thereby minimizing center of gravity excursions with varying loading and fuel burn.
Airframe should cost ~US$20K, MB V6 engine ~US$5K, Ivo prop ~US$2.5K, minimal avionics another US$2.5K.
Ability to run on Jet-A, diesel, biodiesel, etc.
Don't forget the world record the MB cars set with this engine. It's a true endurance athlete.
SixZ for ~US$30K anyone?
Kumaros
It's all Greek to me

[SteveWrightNZ]

There is a lot of free space in the Cozy MK-IV with outboard-mounted twins. You dont need to make much more room to fit two passengers in. Weight and Balance will likely will be a nightmare.

Those 5 blade props look cool, but everywhere I have read shows them to be horribly inefficient. Two blade props seem to be the best overall, with the three-blade being a poor-cousin to it but better for short-field work.

Twin - Coaxial engines - What happens during an engine failure ? Does one windmilling prop blanket the other one badly ? It occurs to me that it might, unless the dead engine can be halted. Until this has been demonstrated I would be hesitant etc..

More questions that answers sorry..

[ShaleDC]

Originally Posted by Kumaros

The consensus seems to be that a Cozy MkVI would need to be roughly 25% bigger and more powerful than a MkIV.
I'm proposing a Spartan Cozy, 25% bigger wings,

Things don't just scale that way. 25% bigger wings by span or by area?

[MarbleTurtle]

I like the IDEA of a diesel engine... but is anyone making one in the 250 HP range that is all aluminum?

[Kumaros]

MT, the Mercedes Benz 3.0 liter aluminum head and block with cast iron cylinder liners V6 is 224HP in standard form. It's trivial to chip it to 250HP (10%) or even 275HP (20% power boost). Dry engine weight is 208kg.
The only extra structure needed in my arrangement would be a stout box connecting the firewall to the spar.
Admittedly, I know next to nothing about aerodynamics; dimensioning the fuselage and the wings/winglets is best left to experts. I'm just suggesting a space saving seating arrangement and an engine that's up to the job.
Kumaros
It's all Greek to me

[SteveWrightNZ]

diesels lurrrrve boost. see cumminsracing.com 5.9 litre 1000hp twin compound turbo diesel. drool.. So likely you can just upgrade to a pair of twins, use a different computer, and then "play it loud muthahhh"

[karoliina]

Looked the pic:
Simple quetion where goes the wing spar?!

Another thing:
the seating arrangement is not very nice - they are way too upright to my taste, especially front seats.
It causes also the requirement for the airframe to be quite tall. And it has consequences too, meaning
substantial amount of drag. And from rear seat, there is no visibility outside (where would you put a window where one could see something?).

Also strength considerations: the structure of Cozy is not strong enough for scaling this much up without
redoing strength analysis. More strength required = more weight = higher angle of attack cruise = drag = slow.

Besides of that, you'd need to propably change wing profiles etc. to get it function properly. It would be nowhere near to Cozy,
about everything would need to be different.

I'd estimate that the 224...275 HP would be way too low. Maybe with twin 600 hp turboprops.

Cozy would not be the perfect candidate to scale up btw. It is already kind of out of proportions, width is multiplied with two.
A 6 seater would be a lot longer craft, with a different design. As a starting point you should look rather Starship and Piaggio Avanti as a reference rather
than a Cozy, unless you planned to fabricate it out of unobtainium and install flux capacitors and a ZPM.

[Wapati8]

Originally Posted by karoliina

Looked the pic:
Simple quetion where goes the wing spar?!

Another thing:
the seating arrangement is not very nice ...

Good questions...

1st of all I would make the seating a little more reclined (like the Cozy or the Long). The software I used (Airplane PDQ) just threw those seats in for perspective. Those were initial drawings to illustrate the scale and the idea. Hmmm where should the main spar go... perhaps under the rear ends of the people sitting in the third row? What do you folks think? Is this a good idea? With some baggage room behind them? Baggage could also be stored between row one and two which are back to back, and of course in the strakes.

As far as the unobtanium is concerned I have my first batch on order, it is set to arrive in January. Otherwise I was planning on lengthening and reinforcing the the structure. This has already been done in airplanes like the 540 Cozy.

I was thinking of making a bulkhead/roll-over structure behind the first row of seats, with a forward opening canopy for the pilot and copilot which ends just after the front row of seats and is secured into the bulkhead/roll-over structure. Also would have a side opening canopy for the rear compartment to access the second and third row of seats (think Cozzzy Girrls plane here).

Perhaps for structural integrity add a longeron (I don't even know if this is the correct thing to call them) about midway down each side of the fuse which run the full length, don't want to add more weight than I need to though. I know when you add the conduits and channels down the sides of the fuselage and the bottom center you add plenty of structural strength so the extra longerons may not be necessary.

I am confident that I can get all of the power I need for this craft from one rotary engine (either turbocharged or supercharged).

Any more questions? Keep them coming, I like this.

[karoliina]

I am on composites course right now.

I have learned so far for example
- consider using Bulent's/ShaleDC's construction method, per plans urethane carving way is not good
- do not use urethane anywhere else than maybe garage door (did i say it, they hate urethane)
- use only L285, L335 is not good
- fiber orientation is critical, 1 degree deviatiion is okay but no more and all fibers must be absolutely straight, just putting them there is not sufficient
... list goes on

now I have an idea how much is wet enough and how to achievee it, but that
is an another strory and also another story is that composites are easy to repair
with correct technique (which I now know).

[gilbertexp]

Has anyone seen this?

http://www.aerovisions.com/skyshark.html