drag, mixture, mags, preignition

At higher altitudes what should you do to the mixture?

Since there are less air molecules, you should lean the mixture decreasing the fuel as well

When you fly high and are descending what should you do?

enrich the mixture, since there are more molecules you would need more fuel. If you do not do this you cause an overly lean mixture.

This will cause detonation and pre-ignition.

Pre-ignition is an abnormal combustion event in a spark ignition engine where the fuel-air mixture ignites prematurely, before the timed spark, due to a hot surface in the combustion chamber. This can cause significant engine damage. 

Pre-ignition cause and effect

Are often times worse than detonation

Cause

-overheated spark plugs

-carbon or lead deposits acting as unintended ignition

-another ignition source causing to mixture to ignite prematurely

Effect

-high engine pressure leads to engine damage

-can cause severe overheating and melting of engine, often resulting in engine failure

Detention

occurs when the fuel air mixture explodes instead of burning evenly.

This can happen as a result of using lower than specified grade of (octane) fuel, by excess engine temperatures, and by overly lean mixture.

If fixed propeller is experiencing detonation during climb out from takeoff lower the nose a little bit

Can lead to engine inefficiency, vibration and noise

damage to piston, cylinder, sparkplugs

What are:

Interference Drag

Skin Drag

Form Drag

Interference drag - parts of the aircraft connected together interfering with smooth airflow

Skin drag -restriction due to the contact of the aircrafts surface

Form drag - shape of aircraft distrusting airflow

What is the magneto system?

creates electrical power without a battery. Is an electrical generator. and the power source for the spark plugs. These two magnetos are split between the spark plugs in each cylinder in case one misfires.

Pros of the magneto system

Cons of magnetos

pro - if there is an electrical failure it will not affect the engine

con - expensive so cars don’t use and it’s hard to repair once damaged

Why could the magneto system fail?

other engine oil and fluids that leak (with age) and entire the magnetos causing deuteration

Piston engine

an internal combustion system that uses pistons when combusted with fuel to transfer energy into mechanical motion

What does the mag check do?

magneto checks the ignition system and that there is fuel to burn

throttle vs mixture

throttle controls the amount of air and fuel entering the engine

mixture controls the fuel to air mixture ratio

throttle air

mixture fuel

Inertia

resistance to change in direction or speed

High to low and low to high

high to low, look out below

low to high, indicate higher than you actually are

2-stroke cycle engine thrust and fuel

efficiency can be greatly compromised

when...

The exhaust is not tuned to the engine.

Combusted fuel is expelled from a 2-stroke

cycle engine through an...

Exhaust Port