Systems PPL ORAL

What engine does the aircraft have?

- Lycoming O360 A4M, 180HP at 2700 RPM

- Hrizontally opposed

Is the airplane carburared or fuel injected?

Carburated (6-pack/G-500 models)

What does carburated mean?

The carburator mixes fuel/air before it enters the cylinders

What does naturally aspirated mean?

The engine draws its air/fuel mixture using atmospheric pressure and piston suction, with no turbo or supercharger

What does air-cooled mean?

Engine cooling relies on airflow over the cylinders from the propeller and ram air.

What are the four strokes of the engine?

1. Intake: Air/fuel mixture enters the cylinder

2. Compression: Piston comresses the mixture

3. Cmbustion (Power): Magnetos ignite the mixture

4. Exhaust: Burned. gases exit the cylinder

How many magnetos does te engine have?

2

What is a magneto?

An engine-driven electrical generator that uses magnets and coils to create high-voltage spark for ignition

Why are there two magnetos?

Redundancy and better combustion efficiency.

Which magneto is used for starting?

The left megneto (with impulse coupling)

How many sparkplugs does the engine have?

8 spark plug (2 per cylinder)

What is the secuence of engine starting?

1. Press starter -> sends power to starter motor.

2. Starter engages the flywheel.

3. Propeller begins turning

4. Pistons start moving

5. Magnetos rotate and generate spark

6. Combustion cycle start (intake, compression, combustion, exhaust)

What privides power to the spark plugs during start?

Magnetos, once they start spinning

What kind of propeller does the aircraft have?

Fixed-pitch sensinich propeller

What is the propeller diameter?

76 inches

What does "angle of incidence" refer to for a propeller?

The blades fixed pitch angle relative to the plane of rotation.

What does the battery?

- Start engine

- Provides power if alternator fails (30 min)

- 24 volts

- 17 amps

What does the alternator?

- Charge the battery

- Provide electricity

- 28 volts

- 70 amps

What is one of main differences between a generator and alternator?

Generator: Produces electrical power proportional to engine RPM -> weak output at low RPM

Alternator: Produces more consistent power at all RPM and is lighter and more reliable (PA-28-181)

Can we jumpstart the airplane? How?

Yes.

The PA-28-181 has an external power receptacle on the right (passenger) side of the tail

Follow the POH external power procedures to avoid electrical system damage

What is vapor lock?

- Occurs on very hot day or acter shutdown when fuel lines get hot

- Heat causes fuel to evaporize, forming bubbles in the fuel system

- These bubbles can restrict or block fuel flow, leading to engine roughness.

What type of fuel delivery system is easier to start on a coild/warm day?

Carbutated -> warm days

Fuel injected -> cold days, mostly due vapor, lock for adverse warm temp starts.

What's a fuel sump's purpose?

It's a law point for water and debris to congregate and be drained out of the fuel system.

*It is important to verify the color of what has been drained because sometimes there can be so much water, you won't get any fuel on your first sump and you won't see any separation.

How many fuel sumps do we have?

3

Why don't we use the electronic fuel pump when we taxi and run up in the archer III?

We are verifying the engine-driven fuel pump is funcioning adecuately

What is the lowest point of our fuel system?

Gascolator

What is preignition and what causes it?

Preignition is when the air-fuel mixture in an engine ignites too early, before the spark plug fires.

• Something hot inside the engine lights the fuel before the spark

• The piston isn’t ready yet ❌

• This can badly damage the engine

Why does water sit at the bottom of the tanks?

It does not mix with fuel, and it weihts 7lbs/gal. (more dense)

What if we use lower grade of fuel?

Detonation:

- Because of a lower grade of fuel (worse of 100 or 100 LL)

- Engine roughness + loss of RPM

- Fuel is exploding in the cylinder rather than burning evenly.

Preignition:

- Fuel ignites before the spark plug

- High cylinder head temperatures

- Carbon deposits inside the cylinder

How much does one gallon of 100LL weight?

6 lbs

What color is 100 LL, 100, 80, and JET A?

Blue, green, red, clear/straw

What would happen if we tried to run our engine on JET A?

It would not run or hydro-lock the engine causing permanent damage

What is detonation?

The explosion of fuel in the cylinders rather than a clear burn

What happen if we burn 80 octane?

Detonation

What kind of fuel do we burn?

100LL and 100

How many tanks?

- Two 25 gal. fuel tanks

- 1 gal. unuable each tank

Why is there a difference between total and usable?

- 2 gal. are in the lines and bottom of the tanks

- Included in the basic empty weight

How much fuel does our airplane hold?

- 50 gallons

- 48 usable

(usable is technically called the fuel load)

How many fuel pumps do we have

1 engine driven

1 electric

Oil quantities (PA-28-181)?

Max: 8Q

Averett min. 4Q

POH min. 2Q

What are the purposes of engine oil?

- Lubricates (moving parts)

- Cools by reducing friction + carrying heat away

- Cleans by removing contaminants

- Seals between piston rings and cylinder walls.