Flashcards in System and Equipment Malfunctions Deck (17)
What causes carb ice and what are the first indications of its presence?
The vaporization of fuel, combined with the expansion of air as passes through the carb, causes a sudden cooling of the mixture. The temp of the air may drop as much 60 degrees within a fraction of a second. Water vapor is squeezed out by this cooling and if the temp in the carb reaches 32 below, the moisture will be deposited as frost/ice inside the carb.
For airplanes with a fixed-pitch propeller, the first indication of carb icing is a loss of RPM. Constant speed props - loss of manifold pressure.
What method is used to determine that carb ice has been eliminated?
When carb heat is applied, there will be a drop in RPM in airplanes equipped with a fixed-pitch prop. If there is ice present, there will be a rise in RPM or manifold pressure after the initial drop (often accompanied by intermittent engine roughness) and then when the carb heat is turned off, the RPM will rise to a setting greater than before application of the heat. The engine shoudl run smoother at this point.
What conditions are favorable for carb icing?
Carb icing is most likely to occur when temperatures are below 70 degrees and the relative humidity is above 80 percent. Carb icing can really occur at any temperature
What is detonation?
Detonation is an uncontrolled, explosive ignition of the fuel/air mixture within the cylinder's combustion chamber. It causes excessive temperature and pressure which, if not corrected, can quickly lead to the failure of the piston, cylinder, or valves. Its characterized by high cylinder head temperatures, and is most likely to occur when operating at high power settings.
When does detonation occur?
a) using a lower grade fuel
b) operating at high manifold pressure in conjunction with low RPM
c) operating engine at high power settings with an excessive lean mixture
What action should be taken if detonation is suspected?
a) ensure the proper grade of fuel is used
b) keep cowl flaps open
c) avoid extended. high power, steep climbs
d) develop the habit of monitoring the engine instruments to verify proper operation according to procedures established by the manufacturer.
What is pre-ignition?
Pre-ignition occurs when the fuel/air mixture ignites prior to the engines normal ignition event resulting in reduced engine power and high operating temperatures. This can be caused by some carbon deposits on a spark plug, cracked plug insulator.
What action should be taken if pre-ignition is suspected?
a) reduce power
b) reduce rate of climb for better cooling
c) enrich fuel mixture
d) open cowl flaps
During the before-takeoff runup, you switch the mags from "BOTH" to the right position and notice there is no RPM drop. What condition does this indicate?
The left P-lead is not grounding, or the engine has been running only on the right magneto because the left magneto has totally failed.
Interpret the following ammeter indications:
a) Ammeter indicated a right deflection (positive). After starting - power from the battery used for starting is being replenished by the alternator. If a full-scale charge is indicated for more than 1 minute, the starter is still engaged and would require a shutdown. During flight - A faulty voltage regulator is causing the alternator to overcharge the battery. Reset the system and if the condition continues, terminated the flight.
b) Ammeter indicates a left deflection (negative). After starting - It is normal during start. At other times this indicates the alternator not functioning or an overload condition exists in the system. The battery is not receiving a charge. During flight - The alternator is not functioning or an overload exists in the system. The battery is not receiving a charge. Possible causes included the master switch was accidentally shut off, of the alternator circuit breaker was tripped.
What action should be taken if the ammeter indicates a continuous discharge while in flight?
The alternator has quit producing a charge, so the alternator circuit breaker should be checked and reset if necessary. If this does not correct the problem, the following should be done:
a) the alternator should be turned off. Pull the circuit breaker or the filed circuit will continue to draw power from the battery.
b) All electrical equipment not essential to the flight should be shut off since the battery is the only source of electrical power.
c) flight should be terminated ASAP
What action should be taken if the ammeter indicates a continuous charge while in flight?
If a continuous excessive rate if charge were allowed for any extended period of time, the battery would overheat and evaporate the electrolyte at an excessive rate. A battery explosion could result. Protection is provided by an over voltage sensor which will shut the alternator down. The following should occur if this happens:
a) Alternator should be turned off by pulling the circuit breaker.
b) All electrical equipment not essential to the flight should be turned off.
c) terminate the flight
During a cross country flight you notice that the oil pressure is low, but the oil temp is normal. What's the problem and what action should be taken?
Low pressure indication could be insufficient oil or clogged oil pressure relief valve. Or bad gauge.
What procedure should be followed concerning a partial loss of power in flight?
First, establish and maintain a suitable airspeed (glidespeed). Find an emergency landing spot. Complete the following checklist:
a) check carb heat
b) check fuel
c) check fuel selector
d) check mixture
e) check the primer
f) check the magnetos in all three positions
What procedures should be followed if an engine fire occurs in flight?
a) mixture to idle
b) fuel selector off
c) master off
d) cabin heat to OFF
e) establish 85 MPH glidespeed
f) execute a forced landing checklist
What is the engine loss in flight checklist?
a) switch fuel to another tank with fuel
b) fuel pump on
c) mixture rich
d) carb heat on
e) check engine gauges
f) check primer
g) check fuel selector