Skyhawk Systems Flashcards
What kind of engine does our 172R have?
Lycoming 360 cubic inch
Horizontally opposed cylinders (4 cylinders)
Air cooled
Normally aspirated
Direct drive - propellor connected to the crank shaft
160HP @ 2400RPM
How does ignition work?
Ignition is provided by two engine driven magnetos on the back of the engine.
They provide spark to 8 spark plugs (two per cylinder)
Engine Lubrication System
Full pressure, wet sump-type lubrication system with aviation grade oil
Capacity of the engine sump is 8 quarts. Engine should not be operated with less than 5 quarts.
What are the two vacuum driven instruments?
Attitude indicator
Directional gyro
Tell me about the fuel vents. What happens if a fuel vent is blocked or clogged?
Blockage of the fuel vent will result in decreasing fuel flow and eventual engine stoppage.
There is an interconnecting vent line from the right fuel tank to the left fuel tank. Left tank is vented overboard through a vent line underneath the left wing.
Both fuel caps are vented as well. The caps are vented to allow outside air pressure to enter the fuel tank and prevent a vacuum from being created inside of the fuel tank.
If the fuel tank did not have a vent, fuel would initially flow from the tank, but as it empties, there would be nothing to replace that space which would create a vacuum and eventually stop fuel flow from the engine.
Vents are installed so air can replace the fuel that is leaving the engine.
As you fly, air gets pushed into the vent which travels to the fuel tank.
What kind of propellor do we have?
McCauley 75inch, 2 blade, all metal, fixed pitch propellor
Describe the landing gear:
Fixed, tricycle type gear consisting of tubular spring steel providing shock absorption in the main wheels.
Oleo (air/oil) strut providing shock absorption on the nose wheel.
The nose strut extends in flight, locking it in place.
Nose wheel has a shimmy dampener which damps nose wheel vibrations during ground ops at high speeds.
Nose wheel is linked to the rudder pedals by a spring loaded steering bungee which turns the wheel up to 10 degrees on each side of center.
Differential braking allows for up to 30 degrees of steering either side of center
What kind of flaps?
Slot type flaps driven electrically by a motor in the right wing.
0
10
20
30
Describe the fuel system:
2 tanks in the wings and a total capacity of 56 gallons, 53 usable.
13 fuel sumps, 5 each wing, 3 under the engine cowling
3 fuel vents - one under left wing and one in each fuel cap
Fuel selector - LEFT, RIGHT, BOTH
Explain carburetor icing and the use of carburetor heat:
At temperatures of 20-70 degrees, it is possible for ice to form in the induction system
This is due to high air velocity through the carburetor Venturi and the absorption of heat from this air by vaporization of fuel
To avoid this, the carburetor heat is provided to replace the heat lost by vaporization.
Initial signs of carburetor icing can be engine roughness and drop in RPM.
What’s the purpose of a magneto check?
A check of the entire ignition system. Making sure that each ignition system operates without help from the other one
Too big of a drop in RPM could mean a fouled plug, bad ignition wire, or improper timing to a bad magneto
No RPM drop could mean a broken p lead. Put the engine to idle and turn ignition to off. If p lead is broken, the engine will continue to run
You can fly with one magneto. The remaining magneto is not working any harder than usual and doesn’t know it’s partner had been switched off.
What are we looking for when we check the volts/amps?
When ammeter is at 0, the battery is fully charged
When the pointer of ammeter is on the “+” side, it shows the charging rate of the battery
When the pointer is on the “-“ side, it means more current is being drawn from the battery than being replaced
Full scale minus means something wrong with the alternator
Full scale positive means something wrong with the regulator
What is the load meter?
The load meter reflects the total percentage of the load placed on the generating capacity of the electrical system by the electrical accessories and battery
What does the voltage regulator do?
A voltage regulator controls the rate of charge to the battery by stabilizing the alternator
The alternator voltage output should be higher than the battery voltage
For example, a 12 volt battery would be fed by an alternator system of approximately 14 volts. The difference in voltage keeps the battery charged
