1. A mixture that is too lean
   A mixture that is too rich
2. A perfectly leaned mixture
   The mixture doesn't matter.

Too lean of a mixture will possibly burn as the gases are forced out past the exhaust valve. This will cause serious overheating of the exhaust valve, and that's a very bad thing.

1. To decrease the wing area
   To relieve the pilot of putting too much pressure on the controls
2. To allow steeper approaches without increasing airspeed
   To look cool

The purpose of the flaps is to generate more lift at a slower airspeed. They also produce more drag, which allows the pilot to fly a steeper descent angle to the runway - without increasing his or her airspeed.

1. They are used during approach and landing to increase wing lift.
   They relieve the pilot of the need to maintain constant back pressure on the flight controls.
2. They move in the opposite direction from one another to control roll.
   They add to the aesthetic of the plane.

Once the airplane is in a stable configuration, the pilot can set the trim to hold the control pressures as they are. This allows the pilot to take his or her hands off the controls, or at least release pressure.

1. Keep the downwind wing lowered
   Keep the direction of motion of the aircraft parallel to the runway
2. Keep the longitudinal axis of the aircraft parallel to the direction of its motion
   Keep the upwind wing lowered

If there is a difference between the direction of travel of the airplane as a whole and the direction that the wheels are pointed, the tires and wheels and landing gear struts are pulled sideways. If the difference is extreme, the tires can pull away from the rims. Better keep the longitudinal axis of the aircraft parallel to the direction of travel!

1. In case the engine-driven pump fails
   When more power is needed
2. When climbing
   When descending

There is a lot of redundancy build into airplanes. This is especially for good reason in case of a fuel-pump failure. No fuel means no engine power, which means forced emergency landing. The auxiliary pump prevents this from happening.

1. Avionics equipment failure
   Navigation equipment failure
2. Engine failure
   Redundant systems will keep everything functioning

If your alternator fails, your battery will take over - for a few minutes. Then you'll be completely without electrical power. If you're flying in clear, blue skies, there isn't too much to worry about. Your engine runs just fine without an alternator, because it gets its spark from your magnetos. And since you can see, you can visually navigate your way to the ground. If you are flying through clouds, that's a different story. You'll need to get yourself out of them as soon as possible.

1. Improved engine performance
   There isn't a reason.
2. Ignition systems are extremely unreliable.
   In case the key breaks

Dual ignition provides two advantages. One is redundancy in the event of in-flight failure of one of the ignition systems. But the other reason is that it allows for more efficient burning of the fuel-air mixture within the combustion chamber.

1. The rate of charge on the battery
   The amount of charge left on the battery
2. The amount of electricity that is currently being used
   The number of electrical items being used

The main job of the ammeter is to monitor the electrical system of the aircraft. It shows if the alternator is producing enough electricity and whether or not the battery is actually receiving that electricity. If the needle drops, then there is likely a problem with the alternator (or generator if the airplane doesn't have an alternator).

1. Pre-ignition
   Detonation
2. Back Firing
   Killing the Engine

Pre-ignition is when the air/fuel mixture in the cylinder ignites before the spark plug fires. The most common cause of pre-ignition is lead deposits within the cylinder or on the spark plugs.

1. 121.5 and 243.0 MHz
   120.5 and 240.0 MHz
2. 118.5 and 236.5 MHz
   110.5 and 350.0 MHz

The ELT is required to be installed on all U.S. registered aircraft. They may be manually activated to transmit a distress signal on either 121.5 or 243.0 or it can be triggered upon impact.

1. The next higher octane aviation gas
   The next lower octane aviation gas
2. Jet fuel
   Diesel

Just in case the pilot is unsure what kind of fuel he or she is carrying, all avgas is color-coded. 100LL is blue, 130 is green, and 82 is purple. You can use a higher octane, but not a lower one.

1. The oil level could be too low.
   There's too much oil.
2. Not enough gas
   Airspeed is too slow.

If a pilot experiences an abnormally high oil temperature indication, it could be a sign that there isn't enough oil to help absorb the excess heat. It is also important to make sure that the temperature sensor is working.

1. Circulation of oil
   Water
2. Fan
   Clouds

Air-cooled engines obviously rely on air flowing over them to keep them cool. This is the number one cooling mechanism. However, circulating oil is also extremely important in order to reduce friction and prevent excessive heat from building up in the first place.

1. The weight of fuel and the weight of air entering the cylinder
   The volume of fuel and the volume of air entering the cylinder
2. The fuel molecules to air molecules in the fuel tanks
   The volume of fuel to the volume of air in the fuel tanks

The fuel/air ratio is determined by the weight of fuel to the weight of air entering the cylinder. The cylinder is where the ignition takes place, which is where the ratio is the most important. This ratio is measured in weight because the volume changes too rapidly.

1. It decreases engine performance.
   It makes it too hot in the cabin.
2. Causes decreased fuel flow
   It increases engine RPM.

Carburetor heat serves an important function. It raises the temperature in the venturi section in order to prevent or remove any ice buildup that could block airflow into the engine. However, in doing so, it also decreases the density of the air (hot air is less dense) which changes the air/fuel ratio, and therefore decreases engine performance.

1. Using the incorrect fuel
   Incorrect throttle setting
2. The engine is too hot.
   Airspeed is too slow.

Mis-fueling can result in complete engine failure. Luckily, avgas is color-coded in order to help prevent mis-fueling in the first place. However, it's important that the pilot and mechanic are vigilant when fueling.

1. Magnificent Seven
   Dirty Dozen
2. Hardy Four
   MEDA

The "Magnificent Seven" is a list of human factors issues. These seven issues are: 1. We work to accentuate the positive and eliminate the negative. 2. Safety is not a game because the price of losing is too high. 3. Just for today - zero error. 4. We all do our part to prevent Murphy from hitting the jackpot. 5. Our signature is our word and more precious than gold. 6. We are all part of the team. 7. We always work with a safety net.

1. To prevent condensation
   To keep the tanks lubricated
2. To make it easy to take off the next day
   In case someone accidentally flies the plane

Water in the fuel tank can seriously degrade the engine’s performance, even preventing the engine from starting or killing the engine after it's started. Filling the fuel tanks prevents condensation.

1. Loss of power
   Excessive oil consumption
2. Internal engine damage
   Faster flight

High engine temperatures are a bad sign. It can cause loss of power (ready for an emergency landing?). It can also cause the aircraft to consume too much oil, leading to low oil pressure and possible engine seizing. And both of those things can cause permanent engine damage.

1. It allows for the most efficient performance.
   It creates more strain, which can be a good thing.
2. It allows for the use of cheaper fuel.
   It allows the plane to travel further.

There are actually several benefits of a constant-speed propeller. One is optimized performance during each phase of flight. You aren't forced to choose between a climb propeller and a cruise propeller. It also allows for improved fuel efficiency and reduces the strain on the engine.

1. During the first 5 minutes after the hour
   Any time
2. Every 30 minutes
   During the midnight hour

An ELT (Emergency Locator Beacon) is an emergency transmitter that is carried onboard the airplane. In the event of an aircraft accident, the ELT transmits a signal on 121.5. It's important to occasionally test the ELT, which can be done during the first 5 minutes of every hour.

1. Temperature between 20°F and 70°F and high humidity
   Below freezing temperatures
2. Low humidity
   Low humidity coupled with below-freezing temperatures

Carburetor icing can occur at temperatures as high as 70 degrees Fahrenheit. As air moves through the venturi, it will cool the air to icing temperatures. This means that the most important factor in determining the possibility of carburetor icing is the humidity in the air. If there is no water, then there can be no icing - no matter how cold it is outside.

1. Enriches it
   Leans it
2. Decreases fuel flow
   Has no effect

Carburetor heat raises the temperature of the air. As the air heats up, it becomes less dense. Once the air is less dense, the ratio of fuel to air increases.

1. Enrich the mixture
   Climb higher
2. Increase engine power
   Land

Air-cooled engines rely most heavily on air flowing over the engine in order to cool it off. Circulating oil also helps keep the engine cool. The third way to cool the engine is to enrichen the mixture. The fuel is actually cooler than the engine, so bringing cooler fuel can actually help remove the heat from the engine.

1. To compensate for decreased air density
   They shouldn't.
2. To decrease engine RPM
   Because the air is made of different molecules

As the plane climbs, the air becomes less dense (there are fewer air molecules flowing into the engine). Because there is less air, the pilot must lessen the amount of fuel allowed to flow in order to keep the fuel/air ratio constant.

1. Lean the mixture
   Lower the nose slightly to increase airspeed
2. Apply carburetor heat
   Lower the flaps

The pilot needs to decrease the heat of the engine. One way to do so is to get more air flowing over the engine (it's air-cooled). The best way to do so is to lower the nose and increase airspeed. More air equals cooler engine.

1. The pilot can choose the blade angle for the most efficient performance.
   The pilot can maintain a desired cruising speed.
2. It provides smoother operation.
   The pilot doesn't have to maintain back pressure.

A constant-speed propeller permits the pilot to select the best blade angle, so that the flight is as efficient as possible. A low blade angle is good for takeoffs, while a higher angle is good for cruise.

1. Low airspeed, high power, high angle of attack
   Low airspeed, low power, low angle of attack
2. High airspeed, high power, high angle of attack
   High airspeed, low power, low angle of attack

The effect of torque increases in direct proportion to engine power, airspeed and airplane attitude. Torque is reduced in higher airspeeds because of the increased stability of more airflow over the wings. Higher power places more torque due to the propeller.

1. At low angles of attack
   At high angles of attack
2. At high airspeeds
   At low airspeeds

P-factor is a result of asymmetric propeller-loading. It is caused because the downward-moving blade on the right produces more thrust than the upward-moving propeller on the left. This effect is amplified when the airplane is at a high angle of attack.

1. Altimeter
   Vertical Speed Indicator
2. GPS
   Airspeed Indicator

The pitot tube provides input for the airspeed indicator only. The airspeed indicator also uses the static port. The altimeter and vertical speed indicator only rely on the static port. The GPS relies on neither.

1. Airspeed Indicator only
   Altimeter only
2. Vertical Speed Indicator only
   The airspeed indicator, altimeter, and vertical speed indicator

All three instruments rely on the static port. The airspeed indicator also relies on the pitot tube for accurate readings.

1. By an independent organization
   By an dependent organization
2. By an internal reporting and auditing system
   By an outsider

A quality system includes procedures for planning, conducting and documenting internal audits to ensure compliance. The procedures must include reporting results of internal audits to those responsible for implementing corrective or preventive action.

1. Preventing and managing error
   Identifying and mitigating error
2. Reducing and containing error
   Ignoring it

The Maintenance Error Decision Aid (MEDA) investigates errors, tries to understand root causes and then implements strategies to prevent and manage accidents. Research shows that most of the factors that contribute to an error can be managed.

1. The starting point
   The intervention point
2. The ending point
   Never a factor

Investigators use the SHEL model. It stands for "software, hardware, environment and liveware." In all instances, the human factor is the starting point. Basically, if something goes wrong, it's almost always our fault!

1. Determining where and why a problem exists
   Determining how to prevent the problem
2. Determining how many factors contribute to the problem
   Hiding the problem

The SHEL model (software/procedures, hardware/machines, environment/ambient, liveware/personnel) is used to determine where and why a problem exists. After running through the SHEL model, then maintenance can go about solving the problem.