FA+
Shop
Low profile... lately.
a year ago
I've been keeping a low profile for a while now... my back has been giving me fits. Laying wrong in bed at night then in the morning I can barely get out of bed is not a lot of fun. My doctor has been zero help. It really kills the creative mood and process, I know others dealing with the same issue... it slows things down a lot as we know but it doesn't stop the process.
I've been doing a little writing, some aircraft sketches and number crunching. It really comes down to what do I want out of my aircraft design. It looks like my design will be about the size of a Piper Cub. That being a 35 foot wing span and 20ish feet long.
To get good short field performance it takes big horsepower and lots of lift at low speeds.
How do you get good short field performance with lower horsepower? The simplest is wing area. From there you can get into complex systems that let you need less wing area but add weight. Mike Pati's Scrappy is one example of being complex.
I'm looking at simple and straightforward Hershey bar wings with a Fowler style flaps. Also in the mix is what airfoil to use? Well the NACA airfoils are off the table because they were never intended to be used on aircraft. They were and are only test specimens and NOT fully developed airfoils for aircraft use. It doesn't help matters that NACAs idea of a light aircraft is a craft with a gross weight of 12,000 pounds.
Harry Riblett took the next step with a few of the NACA airfoils to correct their deficiencies and make them suitable for light aircraft like I'm working on. Using one of his laminar airfoils I can get the lift needed with less drag of a turbulent airfoil. Meaning a bit more speed at cruise speed on the same fuel burn... with 175 square feet of wing area you want cut the drag where you can.
The projected stall speed clean is 39 mph and 29 mph with flaps. When it comes to cruise speed that's more a matter of how much fuel do you want to use an hour. Econo cruise looks to be 95ish mph on under four U.S. gallons an hour. This is also very dependant on the engine used and it's specific fuel consumption per horsepower.
The Aero Momentum engines I'm looking at have a .39 pounds of fuel per horsepower hour at 55 to 60% power. So the numbers say my design should cruise 97 mph at the power setting of 60 horsepower. As we all know your results may vary, but the numbers look good to me.
The fuselage will be Paper Glass, the wings will be aluminum sheet spars and ribs with fabric cover. The flaps and ailerons may be of composite materials for simplicity of manufacture.
Now I need a larger drafting board, my 3A board is just to small for the scale I'm working at on the wings and fuselage... something like a 2A would be sweet.
Blessing all be safe out there.
I've been doing a little writing, some aircraft sketches and number crunching. It really comes down to what do I want out of my aircraft design. It looks like my design will be about the size of a Piper Cub. That being a 35 foot wing span and 20ish feet long.
To get good short field performance it takes big horsepower and lots of lift at low speeds.
How do you get good short field performance with lower horsepower? The simplest is wing area. From there you can get into complex systems that let you need less wing area but add weight. Mike Pati's Scrappy is one example of being complex.
I'm looking at simple and straightforward Hershey bar wings with a Fowler style flaps. Also in the mix is what airfoil to use? Well the NACA airfoils are off the table because they were never intended to be used on aircraft. They were and are only test specimens and NOT fully developed airfoils for aircraft use. It doesn't help matters that NACAs idea of a light aircraft is a craft with a gross weight of 12,000 pounds.
Harry Riblett took the next step with a few of the NACA airfoils to correct their deficiencies and make them suitable for light aircraft like I'm working on. Using one of his laminar airfoils I can get the lift needed with less drag of a turbulent airfoil. Meaning a bit more speed at cruise speed on the same fuel burn... with 175 square feet of wing area you want cut the drag where you can.
The projected stall speed clean is 39 mph and 29 mph with flaps. When it comes to cruise speed that's more a matter of how much fuel do you want to use an hour. Econo cruise looks to be 95ish mph on under four U.S. gallons an hour. This is also very dependant on the engine used and it's specific fuel consumption per horsepower.
The Aero Momentum engines I'm looking at have a .39 pounds of fuel per horsepower hour at 55 to 60% power. So the numbers say my design should cruise 97 mph at the power setting of 60 horsepower. As we all know your results may vary, but the numbers look good to me.
The fuselage will be Paper Glass, the wings will be aluminum sheet spars and ribs with fabric cover. The flaps and ailerons may be of composite materials for simplicity of manufacture.
Now I need a larger drafting board, my 3A board is just to small for the scale I'm working at on the wings and fuselage... something like a 2A would be sweet.
Blessing all be safe out there.
Vix
Sorry that you're having to suffer with the back issues... =/