During aircraft construction you need to think about the necessary tools, space to work in, colors and paint job, workbench and much more. In this part we take a look at these things, so that when you finally start to build your dream plane you hopefully do not run into any surprises.

When ordering aircraft tools from any supply company, keep in mind that they do not have all parts in stock. Items will be on back order. So order well in advance and make sure they ship when complete. This saves shipping costs.

Engines, propellers and electronics

Aircraft Engines
Aircraft usually need some type of power to get them going. Gliders get themselves in the air by either a towing airplane in front of them or via a winch and cable, after which they use thermals trying to delay the inevitable return to mother earth. Us guys in powered airplanes use an engine with a propeller and some maybe even an exotic turbofan. Engines come in all kinds of shapes and sizes. Most common types are: 4, 6 and 8 opposed cylinders from Lycoming, Continental, Rotax, Jabiru and Subaru engine types. Radial engines like the 7 or 9 cylinder Rotec (a very impressive piece of work). Diesel engines running JET-A can also be seen on the platform. The smaller two stroke engines from Rotax or Hirth are usually used in small ultralights.
The TBO (time between overhaul) is determined by the manufacturer and is usually around 2000 hours. JET engines have a much higher TBO.

The power of aircraft engines in this class is usually between 80 Hp and 180 Hp (for the small two place types) and between 200 and 350 Hp for the larger four seat Lancair type of aircraft. Exception is the Murphy Moose which has a nine cylinder radial engine with 360 - 400 Hp.

Development is going on to power very light aircraft and gliders with an electric motor. The firm Pipistrel (see: http://www.pipistrel.si) is test flying with a glider. Hopefully, when solar cells obtain a much higher yield (16% now), it should be possible to totally run on electric power by recharging the onboard batteries through the solar cells on the wings, even while flying!

Engines with a turbo compressor
Basically, turbos are exhaust gas driven air compressors. This compressed (and warmed) air is then fed into the intake of the engine, sometimes through an intercooler. The advantage is that energy (heat and speed) in the exhaust gasses are used which would otherwise have been lost in space.
This principle can be used in two-ways: add more air (pressurize the intake) or keep the pressure of the air constant in the intake. The first type is called turbocharging and the second turbo normalizing. With turbo normalizing the intake is kept at a constant sea level pressure (30") regardless of altitude (or until the system reaches its limit). This imposes much less stress on the engine compared to turbocharging. With turbocharging the intake is usually pressurized to 39-40" MAP (there are exceptions), more air means that more fuel can be added and the engine will produce more power. This over boosting is time limited, usually 1-5 minutes, depending on engine design.

Aircraft Propellers
The power from an engine, be it an avgas or diesel, must be transformed to useful trust. Or else there isn't much flying going on. Propellers are used for that purpose. They come in 2, 3 and more blades and can be made from metal, wood or composites. This depends (among other things) on the designer or on how much power, torque and rpm the engine has. Propellers can be fixed (for climb or cruise purposes) or adjustable (ground or in flight). Adjustable propellers have an advantage over fixed types, they can be set for start, climb and cruise RPMs. Constant-speed propellers keep the preset rpm constant relieving the pilot from this task.
These propellers are controlled by either an electric motor in the spinner or a cylinder actuated by oil pressure from the engine. The electric types can be made rather sophisticated by a microprocessor controller with settings like: feather, take-off, cruise, climb, manual control and hysteresis function. All values can be set by the pilot.
Choosing the right propeller is a difficult task as a number of variables, like engine rpm, torque, power, noise limitations (regulatory) type of aircraft (its ideal cruise and climb speeds) influence each other so that usually the chosen propeller design is a compromise of all these variables.

Fuel and Fuel system
Piston powered aircraft generally consume AVgas, aviation gasoline. It is like a high octane autogas, only more expensive (in Europe about 10 USD/gallon), high lead (despite its LL, low lead, designation) and it is more controlled and more stable. Problem is that the future of AVgas is not certain. No surprise that diesel engines are getting more and more popular. These engines can use JET-A(1), road diesel, agricultural (red) diesel and even biodiesel is possible.
Small aircraft like the Pelican PL, Zenair types and the likes mostly have a Rotax 912, 912S or the 914 turbo engine capable of running on mogas. Much cheaper but not certified and the fuel is not controlled the way AVgas is. Follow this link to read more on aviation fuels.

Usually, high wing aircraft like your average Cessna, Murphy etc. have a fuel tank in each wing. Aluminum fuel lines run then to a fuel selector in the cabin with Left, Right, Both and Off selections. The Cessna 150/2 has a On, Off type of selector and both tanks feed the engine at the same time. Fuel is gravity feed and sometimes a low pressure fuel pump is added to aid starting and used when switching tanks during flight and on take-off and landing.
Low wing aircraft normally would have a tank in each wing, fuel selector in the cabin and have an extra electrical fuel pump. Gravity feed is more difficult as the wing (fuel) sits lower than the engine and the pump needs to push the fuel to the engine. There are some type of aircraft (Lancair has one) that have an extra header tank behind the instrument panel. More on refueling aircraft.

Avionics, Instrument Panel and EFIS
Flight and engine instruments can be the old school style type round gauges we all (well most of us) learned to fly with. These are familiar to everyone. Latest trend is glass in cockpits. From addon EFIS like the Blue Mountain Avionics series to complete integrated systems with 8" and 10" color LCD screens (daylight visibile!) from Garmin, where even the radio's (COMM and NAV) and engine instruments are integrated. These can be coupled to an autopilot and programmed to fly the entire route and instrument approach. You still would have to do the landing yourself.
Installing an EFIS system saves weight and cleans up your panel. It also means that you could go without a vacuumsystem and remove the hoses, pump and hardware (more weight savings). All of this could mean a single point of failure in the cockpit. But even with the sixpack we normally have, would you go flying if your altimeter does not work?