- 1 What is a mag on a plane?
- 2 How do you do a mag check?
- 3 What is a hot prop?
- 4 What is a live mag check?
- 5 What is AP lead?
- 6 Why do planes have 2 magnetos?
- 7 Why do we do a mag check?
- 8 What causes excessive mag drop?
- 9 What causes a magneto to fail?
- 10 How do I know if my magneto is grounded?
- 11 What is a hot Magneto?
- 12 How do you clear fouled spark plugs?
- 13 What happens if a magneto fails?
- 14 What does Magneto mean?
- 15 How do you diagnose a bad Magneto?
What is a mag on a plane?
An aircraft magneto is an engine driven electrical generator that uses permanent magnets and coils to produce high voltage to fire the aircraft spark plugs. Aircraft magnetos are used in piston aircraft engines and known for their simplicity and reliability. You can learn more about a dual magneto by clicking here.
How do you do a mag check?
The in-flight mag check is performed at normal cruise power and normal lean mixture (preferably LOP). Run the engine on each individual mag for at least 15 or 20 seconds. Ensure that all EGTs rise, that they are stable, and that the engine runs smoothly on each mag individually.
What is a hot prop?
For a propeller to be hot, two things have to happen. There has to be some small amount of fuel left in the engine, and a spark has to reach the spark plugs. Under normal conditions, having the magneto switches or key turned to the Off position will prevent any spark from reaching the spark plugs.
What is a live mag check?
Live mag check Both magnetos are switched off momentarily in order to ensure that the engine does cease running. The main purpose behind both dead cut and live mag checks before shutting the engine down is to enable early discovery of any fault that may have developed during the flight.
What is AP lead?
Your P lead is the wire connecting the starter switch to your magneto’s primary windings, thus P lead. Their primary purpose is to ground the magnetos to avoid accidental starts. The easiest way to check starts on the ground, after each flight students can perform a ground check.
Why do planes have 2 magnetos?
REDUNDANCY Airplanes have two magnetos, left and right, each of which fires one spark plug per cylinder, creating a redundant system that allows the engine to operate at full power independent of the engine-driven alternator.
Why do we do a mag check?
Checking the magnetos (let’s call them mags ) is really a check of the entire ignition system. The ignition system is what causes the fuel to burn, which results in the wonderfully loud engine noise we pilots love to hear.
What causes excessive mag drop?
IME the most common cause of excessive mag drop without roughness is retarded timing. If this engine has timing marks and the mechanic uses them to set the mags the marks could be off. and mag timing can drift with operating time.
What causes a magneto to fail?
The voltage generated across magneto coils is quite high, in the order of 20,000 volt if no spark plugs are in place. The high voltage will simply arc across the gap. The gap will widen as the wire ends melt further apart and soon the adjacent turns will be affected so the coil will eventually fail.
How do I know if my magneto is grounded?
There is an easy check you can perform in the cockpit to make sure your mags are grounded. Before you shut down the engine, simply turn the key briefly to the OFF position. If the engine quits when you turn the key to OFF you can rest assured that the mags are grounded.
What is a hot Magneto?
Travis, what you are describing sounds like you have a “ hot ” mag. Basically a magneto that most likely has a broken P-lead (it could also be the mag. switch). The P-lead goes between the start switch and the magneto. The p-lead functions to ground the magneto (turn it off).
How do you clear fouled spark plugs?
Start with the fouled spark plug possibility. Try clearing the plugs by running your engine up to 2000 RPM on both mags leaning to about 50 RPM lean of peak (continue to lean until you maximize RPM, then lean further until you lose about 50 RPM).
What happens if a magneto fails?
If a magneto fails in flight, especially in a single you might not even notice initially; there will be a slight reduction of engine power, just like during the magneto check, but the engine will keep humming along on the remaining magneto.
What does Magneto mean?
: a magnetoelectric machine especially: an alternator with permanent magnets used to generate current for the ignition in an internal combustion engine.
How do you diagnose a bad Magneto?
Most “ bad mag checks” are spark plug related. The spark plug is fouled and shorted to ground or is open and the magneto, which is functioning normally, is unable to fire it. A typical bad plug will cause an immediate drop of 250 or more RPM, at the mag check. The key indicator is the suddenness of the drop.