Aero Ex - Valkyrie 1 Design

[Peasant_Pilot]

Evening  ladies and Gentlemen, so here is a bit of a concept iv been designing for the past few months, still very early stages and so much work still needing to be done but the basic layout is now pretty much where i want it. I am in no way experienced in CAD but iv been teaching myself what i can and learning from Youtube as much as possible

 

So here is the basic specs and plan

• 310kg empty weight (600kg MTOW)
• 120kn cruise at 5200rpm
• Utilize the Rotax 912 ULS 100hp
• Home built 19 Category RAAUS registration
• fiberglass/carbon Airframe with Foam Core Bulkheads
• 2 Seat
• Tricycle Gear Configuration
• the Price........ to be the most affordable composite airframe(no avionics or motor) on the Market in Australia - Under 25k

 

Im designing this to be able to be manufactured and purchased as a 51% kit, with the idea that the bare airframe can be assembled and on its legs in a 2 week period(100 Hours) , now this is bare airframe and engine mounted, the Fuselage will be in 2 halves with a moulded cockpit that will be mounted as the halves are joined. wings will be in 2 halves and foam core ribs will have to be set and epoxied in place along with the skins. 

 the following still needs to be designed

• Wing root fairings
• landing gear
• cockpit and panel
• vertical stab profile
• wingtips
• and a bunch of detail work.

Currently im at the point where i can start doing some CFD on the Aircraft model and hoping to start that soon. 

 

There will be a lot of changes to be made and im still very much learning, might be a pipe dream at this point but im going to see where it takes me

 

 

 

[facthunter]

Good luck with it PP. Plenty of work there.  Nev

[Peasant_Pilot]

Thanks mate

 

1 hour ago, facthunter said:

Good luck with it PP. Plenty of work there. Nev

 

 

 

 

[onetrack]

I always wondered why light aircraft manufacturers didn't come up with a "two halves fuselage shell" design, as this was the feature that made the Mosquito a winner, when it came to ease of construction and low cost of construction.

 

https://www.awm.gov.au/collection/C992569

 

https://www.awm.gov.au/collection/C992570

 

Edited February 16, 2023 by onetrack

[Marty_d]

It's a nice looking bird, and you know what they say - if it looks right it usually flies right!

 

Good luck with it.  Planning to blow your own canopies or get that done?

[facthunter]

The cockpit cut out is the Big weakness in it Monococque (Single shell Fr) Carbon/ glass etc is probably the future. Carbon fibre is dangerous to work with.   Nev

[Peasant_Pilot]

4 hours ago, onetrack said:

I always wondered why light aircraft manufacturers didn't come up with a "two halves fuselage shell" design, as this was the feature that made the Mosquito a winner, when it came to ease of construction and low cost of construction.

 

https://www.awm.gov.au/collection/C992569

 

https://www.awm.gov.au/collection/C992570

 

Im a big fan of the Mozzy, actually didnt know this...very interesting. i thought the split fuse would be a good idea for a few reasons, it will help with the 51% build, the cockpit assembly will be its own structure with the spar carry throughs in It and reinforced cockpit and so on so you will need to close it all in together.  Im designing a jig that will come in the kit to align the cockpit and 2 halves. trying to simplify the build for people to encourage more home building at actual affordable pricing.

[Peasant_Pilot]

43 minutes ago, Marty_d said:

It's a nice looking bird, and you know what they say - if it looks right it usually flies right!

 

Good luck with it.  Planning to blow your own canopies or get that done?

Cheers man, i figure the the main difference between an ugly bird and an expensive pretty bird is essentially the moulds/design, so if i can get that right....the build process should follow, thats the theory anyway. 

 

As for the Canopy, that is up in the air at the moment, i like the canopy design but might need to redesign as a 2 piece....unsure about the blowing process for a canopy and where to start. i have an idea on the process but i think getting sufficient clarity will be key, its the only part in the design i might have to potentially outsource.

Edited February 16, 2023 by Peasant_Pilot

[Peasant_Pilot]

14 minutes ago, facthunter said:

The cockpit cut out is the Big weakness in it Monococque (Single shell Fr) Carbon/ glass etc is probably the future. Carbon fibre is dangerous to work with.   Nev

I tend to agree, have looked at running ir as a 2 piece Canopy. going to look at a roll bar essentially to be built into the cockpit structure

[onetrack]

The major thing is to design a cabin that doesn't crush (buckle in halves) upon impact in a hard landing. If you're going to dive into terra firma at 45° or steeper, then nothing is going to stop you getting killed.

But a cabin that doesn't fold up in a forced landing is a crucial factor in any new light aircraft design, and can be a big selling point.

[Peasant_Pilot]

29 minutes ago, onetrack said:

The major thing is to design a cabin that doesn't crush (buckle in halves) upon impact in a hard landing. If you're going to dive into terra firma at 45° or steeper, then nothing is going to stop you getting killed.

But a cabin that doesn't fold up in a forced landing is a crucial factor in any new light aircraft design, and can be a big selling point.

so the concept  i was working with was going to be a Chromoly Peremiter frame around the pilot and passanger, that idea came from sitting in a formula one car. the idea essentially is to keep them as safe as possible. the first step is to design a cockpit seperatley from the aircraft and build the airframe around it. safety is at the top of the list.... but i have so much to learn about it all, appreciate all the info, i need as much as i can get

Edited February 16, 2023 by Peasant_Pilot

[Geoff_H]

Some years ago I designed and partially finished the prototype of a very similar project.  The two halves of the fuselage were a top and a bottom.  The main issue with a monocoque skin.  A section between bulkheads has to have  buckling resistance.  This is where I had difficulty with design,a single skin thickness either had a large weight to resist buckling of many bulkheads close together,  I chose a composite skin, bad choice in retrospect.  I had to mould a core to shape then "glue" it to the outer skin then epoxy a layer on the inside.  Without the ability to experiment with strengths of composite structures I made it far too heavy.  I was looking at doing a master's in aeronautical doing experimental techniques until I got an away from home contract and abandend the project.  Maybe stringers that were cast and attached to the skinsin the moulds would have been better, hindsight is  so 20-20 vision.  I made two tails, one using this method and one using cut foam with a cast skin attached ( no sanding required) the greatest surprise was that there was no measurable difference in the final weight 

Good luck with your project.

Geoff

[Geoff_H]

Somewhere I may have the 3D CAD files that I made, it was around 25 years ago.  They were done in AutoCAD.  I will have a look to see what has survived if interested.

[Peasant_Pilot]

It definitely comes with its challenges, I definitely don't have the answer to the solution. I do have some ideas on maintaining strength in the fuselage especially around the tail section so I'm hoping when I start doing some section testing I can find a good solution. Would be interested to see your prototype work Geoff. It's the technical and fabrication side that really has me wanting to keep pushing through this. 

 

 

 

 

 

 

 

 

 

 

 

[Thruster88]

12 hours ago, onetrack said:

The major thing is to design a cabin that doesn't crush (buckle in halves) upon impact in a hard landing. If you're going to dive into terra firma at 45° or steeper, then nothing is going to stop you getting killed.

But a cabin that doesn't fold up in a forced landing is a crucial factor in any new light aircraft design, and can be a big selling point.

One compromise with all sport aircraft is between speed and safety. Low frontal area dictates the pilot will be sitting on the floor, almost no energy absorbing space in the event of a big mush. You can appear fine externally and still be dead. Cessnas have nice tall energy absorbing seats but they are slow and boring. 

 

PP you should check out a glastar if you can, they have a steel frame around the cabin inside a composite skin.

 

[Geoff_H]

I put 2 layers of Kevlar around the pilot area.  It may have helped safety but took a huge toll on weight

[Geoff_H]

55 minutes ago, Thruster88 said:

One compromise with all sport aircraft is between speed and safety. Low frontal area dictates the pilot will be sitting on the floor, almost no energy absorbing space in the event of a big mush. You can appear fine externally and still be dead. Cessnas have nice tall energy absorbing seats but they are slow and boring. 

 

PP you should check out a glastar if you can, they have a steel frame around the cabin inside a composite skin.

 

Mooney have a steel frame around an aluminium skin in the pilot/passenger region.  The tail is monocoque, the tail hinges off the steel frame to provide reduced drag trim.  There are fewer deaths from Mooney accidents.

[Geoff_H]

The Plugs that I made and a print of a view of the AutoCAD file.

 

Geoff

[Peasant_Pilot]

Very cool mate, good to see. I'll be hopefully starting to do the plug soon

[Geoff_H]

Those plugs were made by using the 3d autocad file to make 2inch slices through the cabin, print the slices full size, transfering the prints to particle board, then using foam (the florist style foam) sandwiched in between the particle board and sanding using particle board as guides.  Long and laborious but effective.

[Peasant_Pilot]

Thats very similar to what I'm planning on doing. Build a central beam with rotisserie style mounts and I'll be mounting bulkhead/rib section all the way along.....foam in between then skin it

 

 

 

 

 

 

 

[Peasant_Pilot]

Some of the early work on the model, started with the side profile sketch. The biggest hurtle has been learning CAD

 

 

 

[Geoff_H]

Looks great.

[Peasant_Pilot]

Thanks mate

[skippydiesel]

All the best - always wondered why we don't produce such advanced sport aircraft in Australia.

 

You may like to check out the ATEC 321 Faeta (an aircraft with an extraordinarily wide flight envelope) for a few design pointers and performance goal setting

 

https://www.atecaircraft.eu/en

https://www.atecplanes.com.au/

 

There are two variants -. NG (looks much like your concept) and standard, which has a T tail (my preferred option being cheaper to buy and has a lower stall with same 134 knot cruise)