It depends on the type and weight of aircraft, power of engine and type of propeller.
Because it fast and relaxing way to traver
They're carnivores and hunters. They need to be able to move fast to catch their prey.
It depends on how big the airplane is. If it's a Boeing 747, it'll need about 180 knots to prevent stalling, but if its a Cessna, it'll need only about 55 knots.
If you need to go a long ways, if you need to go fast, or if you need to carry a lot of weight.
A rubber band boat works much like a rubber band airplane. First you need to build the boat itself. Then you need to make a propeller. The propeller shaft needs to run through the inside of the boat, not below the boat. With the prop below the water. The propeller shaft should not go the full length of the boat. About halfway through put a loop in the shaft. Then to the front of the boat attach a rubber band. Then run the rubber band through the loop in propeller shaft. Now twist the prop and the rubber band should twist around and around. When it's good and tight let go and the propeller should spin. Allowing the boat to move forward in the water. Mind you the shaft needs to be a thin piece of metal, as it will be difficult to make it water tight.
You need, a electric motor, a power source (battery), blades or propeller to attactach tot he motor so when they spin the move (displace) the air.
A need for fast transportation and the ability to travel to locations previously not reachable by foot, car, and train prompted the invention of the airplane.
The population of Hoffmann Propeller is not an applicable metric as it is a company or organization, not a residential area. If you are referring to the number of employees or team members at Hoffmann Propeller, that information would need to be obtained directly from the company.
A motorcycle engine can be converted to power an airplane if the aircraft is registered and placarded as an experimental aircraft. They can't be installed in a certified plane without FAA inspection and approval. Engines such as a 2-cylinder, horizontally opposed BMW motor need a PSRU, or propeller speed reduction unit, to reduce the engine's RPM to match the propeller's RPM.
you just need to have confidence and cup your hands when you swim move your legs as fast as you can and that should do it.
they dont need tail