Geoff_H

I have worked with the trent engine range listed in the brake fuel efficiency stated above. Great engine with multiple shafts. Their are a range of Trent's. The one I worked with was a stationary derivative of the Airbus 380 engines. They have just made a Trent 1000, Rolls Royce have been testing it using renewable style energy fuels. The article leaves out the ABB come Siemens Multiple burner turbine. Much better efficiency.

I have thought that the dual cycle cycle piston engines offer better hope. , Mercedes get 400hp from a 2litre engine with quite high efficiency, around same as cheaper GT designns.

"Another key feature is that WW2 piston aviation engine efficiencies still beat the best very best turbine engines. I occasionally wonder what they could do with modern injectors and turbocharger technology." GE have produced a 50+% efficient engine. Admittedly it had inlet cooling, water injection and steam cooling of the inlet....stationary engine too heavy to fly lol

. Directions YBRL Borroloola Airport NT Landing $23.6363 per tonne, minimum $68.18 Does this fee promote safe aircraft operation. It is unattended with surveillance cameras. It promotes pilots not giving circuit calls. I left Cessnock as aircraft would come from out of the blue, no calls, fees are quite high.

That aircraft designed and made in regional Victoria had an undercarriage test device to prove the design. They made a machine that automatically raised the undercarriage connected to a weight, which I expect was the aircraft AUW, and then dropped the weight and landing gear. Don't know what results they got but it seemed a great testing device.

Agreed. It was late and I was tired. I mixed metric and ft.......I did leave a caveat that it might be wrong. Thanks for the assistance.

I think FAR23 requirement for certified aircraft is a downward velocity of 20 ft/second must be able to be absorbed and still be usable. Have to look up height to give that height but if I recall my high school physics it is 20ft, don't assume that this is correct

Maybe there are some political websites where American politics would be better discussed.

The French plans for a Cri Cri have both inch and metre dimensions. All inch are decimal. My lathe has both inch and mm calibration. I use both but prefer metric. When my daughter first went to school in Plano TX she was asked how many inches in a mile. This was an American intelligence test. They said that she was just an ordinary student not know such basic stuff. 3 years later aged 14 she had completed all high school mathematics and if we had stayed they would have bussed her to a university to continue her maths. She now has a PhD. I asked her when she used the English system which she preferred. She just looked at me as though I was stupid..."metric she replied". I must add that all science is taught in Texas in metric, maybe all of USA but I am not sure.

The Americans call it the English system. When I worked in Texas we had an engineer that would always convert English/imperial system to metric system, do all calculations in metric then convert results to English/ imperial system. Claimed it was easier.

Should be calcs not cakes

Vertical loads that are supported on the ground had no trouble whatsoever to even a small slab full stop the problem arises when you lose support underneath the slab and it becomes a cantilevered beam. If this happens you can easily crack the slab this is what usually cracks slabs. I find it when I go to a structural engineer and force him to show me his cakes so he's not over designing it that I save a lot of money in steel

Sorry my advice is consult an engineer. The edge support or restraint will determine what shear needs to be resisted at edges. I am a mechanical engineer and I always consult a civil/ geotechnical engineer on design. The thing that will trash the job in a few years are the assumptions that are made. An engineer with experience will guard against making an assumption that this slab is just like one seen on the other side of Australia. Best to find an engineer that works on structures near where your hangar will be built. Don't put pads under the slab unless specifically designed and built correctly. They can actually make the slab weaker

Sorry my advice is consult an engineer. The edge support or restraint will determine what shear needs to be resisted at edges. I am a mechanical engineer and I always consult a civil/ geotechnical engineer on design. The thing that will trash the job in a few years are the assumptions that are made. An engineer with experience will guard against making an assumption that this slab is just like one seen on the other side of Australia. Best to find an engineer that works on structures near where your hangar will be built.

Maximum weight is 7ton. Pressure on concrete would be the tyre pressure. Only problem is bending moment from ground under the concrete not fully supporting the concrete. Tale the 7 tonne point loading ( actually less when shared between wheels) to a civil engineer or geotechnical engineer. He/she will probably tell you off the top of his head if he knows where the hangar is to be built ( they have charts about ground support capabilities).

Great!

I also think that you would be better with "time away". I know that it has helped me enormously. Solved problems, got enthused again. Don't burn your self out. Nothing to do with perseverance. Just as your body needs rest so does your mind.

Why not sell a share of the aircraft? The new shareholder gives money, maybe supplies the engine or similar, and finishes the aircraft, then you both own it. I may be wrong. I think that with a mentor you may have a much better experience. You need moral help. I have been there and would have given up except for moral assistance of other builders

I recently had 3 problems in my project. I got very disappointed. I left it alone for 3 months and did "honey do's". Two solutions have come to me and I am back building. Danny when you get a problem why don't you publish it here. Maybe with pics and manual extracts. I am sure that we would all be here for you. And I expect that the problem could be solved. Maybe you need to get assistance on techniques or methods of manufacture. I am sure that you will get the job done and be so proud of yourself. Don't sell, you will probably loose money and self esteem. Keep going. Show us all pictures of your progress.

Why not sell a share of the aircraft? The new shareholder gives money, maybe supplies the engine or similar, and finishes the aircraft, then you both own it. I am guessing that the problem that you are having is with engine and avionics. I may be wrong. I think that with a mentor you may have a much better experience. You need moral help. I have been there and would have given up except for moral assistance of other builders

Danny, Where have you got the project to. Related to the 3-week build?

Danny what is giving you the most problems? Is there anything that we can do remotely?

https://www.gap.aero/pdf/bushcat/3week-Bushcat.pdf So how many weeks have taken Danny? Is this a real estimate?

I am about halfway through my own design, aerodynamically it is very similar to an existing design. Before I began I built many test pieces and tested them to destruction. As it is a composite design I have difficulties getting design values for calculations. So it is a little heavy. At one stage some years ago I considered doinfya masters in composite design criteria. One big problem that I had is what would the shear stress of the main spars. Assumed that the max shear stress was the max epoxy stress. The cloth may add extra strength but I went on the side of safety, it now seems a little heavy. It is ok to use the load test to make sure that things are ok...but... What if your dynamic loads are different to the static loads. Throughout my career I found that it's not the calculations that bite you in the backside. 99%of the time, it is the incorrect assumptions. The math will make the aircraft lighter. I was taught that anyone can build anything, but an engineer should be able to do it for far less cost, math can help. If you are designing your own design please get someone to do maths on the critical parts. Even a strut can buckle in compression but be super strong in tension. Negative G's may buckle a strut. Fibreglass structures are notoriously weak in shear. Using mathematics can also stop making 6 parts before the final is made, I have done the math and still had to make the part 6 times before the final that works. However experiment experiment experiment. I have been using carbon infused nylon and 3d printing. I have used it in some parts ..I still have reservations, but they are light. Fantastic for cheaper materials and jigs and alignment tools.

Efficiency often depends upon the design. Our turbine had moving pitch blades that made compression variable. That changed efficiency. But not sure of aircraft GTs air flow control.