PPL Revision Flashcards
- What role do the piston rings play in the operation of an internal combustion engine?
Piston rings do Piston Rings do the following jobs:
- They seal the gasses in the chamber and prevent them from leaking around the sides of the piston. This improves power.
- They reduce friction by reducing the surface area of the piston that comes in contact with the cylinder wall. (If we didn’t have them then the entire piston would be rubbing against the cylinder wall.)
- What are the 4 stages in the Otto cycle?
Intake, Compression, Ignition, Exhaust.
Suck, Squeeze, Bang, Blow
- Why do modern aeroplanes user a dual ignition system?
A dual ignition system improves safety and provides better combustion, therefore, more power. (Notice the drop in RPM when each system is selected separately during engine run ups.) Each system is powered by a separate magneto. The magnetos are completely self sufficient once started and are independent from each other and the electrical system.
- How does air density effect the power output of a normally aspirated engine?
The air density will influence the fuel/air ratio being burnt in our engine. To operate correctly this ratio must be within certain limits. As air density reduces, the air being drawn into our cylinders reduces. This leads to a reduction in fuel so that the correct ratio can be maintained. This results in a lower volume of fuel and air being burnt in our cylinders and a reduction in power.
- A fluctuating oil pressure gauge is indicative of….?
Low oil level. The oil level in the sump naturally varies during engine operation as oil is pumped through the engine and returned to the sump. A fluctuating oil pressure occurs when the feeder pump (sucks the oil from the sump) is exposed to air as it leaves the sump and submerged again when the oil returns
- What is a-possible problem if a centre zero ammeter is showing a discharge and what action would you take?
Possible problems include: a failed alternator, a broken gauge.
Confirm that the alternator has failed by referring to the alternator warning light. Reduce electrical load as much as possible and check for any popped circuit breakers. Recycle the master switch. If the ammeter is still showing a discharge then turn the ALT side of the master switch off and land as soon as practical.
- State the atmospheric conditions conducive to the formation of throttle ice, induction ice and impact ice describe the symptoms that would alert you to their presence?
The formation of icing is dependent on humidity and temperature.
The highest risk of engine icing is when humidity is greater than 60% and temperature is between -5 and +15 degrees Celsius, but has been know to occur with the humidity greater than 20% and the temperature between -5 and + 35 degrees celsius.
- What is the danger of progressive throttle increments if engine ice is not diagnosed?
As the ice builds on ice that is already present, the throttle needs to be slowly increased in order to maintain power. Eventually full throttle will be required to maintain power. The power will then begin to decrease until the engine stops.
- What services are provided by the aeroplanes hydraulic and aeroplane systems?
In the Piper Tomahawk the hydraulic system provides for the aeroplanes braking system.
The Vacuum system powers the gyroscopes in the Artificial Horizon and the Directional Gyro. The Turn Coordinator is powered by the electrical system (spins up when the Master Switch is turned on).
- What potential problems can arise from mixing hydraulic fluids?
If mineral based and vegetable based Hydraulic fluids are mixed a heavy ‘gum’ will result. This will clog the hydraulic system and eventually lead to system failure.
- On an aircraft fitted with a ffixed pitch propeller, describe the correct method of leaning the mixture, both with EGT and without EGT?
Without an EGT: Slowly lean the mixture while listening to the engine note. The RPM will gradually increase as the fuel/air mixture approaches the chemically correct ratio (1:15). Once this point is passed the RPM will drop. Enrich the mixture until it is once again running at peak performance and then push the control in about another 15mm for better engine cooling.
With an EGT: Slowly lean the mixture while watching the EGT. As the fuel/air mixture approaches the chemically correct ratio the mixture will burn hotter, this is shown by a rise in the EGT. When the chemically correct point is passed the EGT will show a decrease in temperature. Enrich the mixture until it is once again running at peak temperature. Continue to enrich the mixture until the engine is running at 50 degrees below peak temperature.
- State 5th potential problems of prolonged idling at a high outside air temperature.
A high OAT will result in the air being less dense. A reduced density means that the fuel/air mixture will be rich. This will result in un-burnt fuel left in the cylinders. As this fuel evaporates it leaves behind impurities (carbon, lead etc) that can clog the spark plugs (carbon fouling) and in extreme cases lead to pre ignition. At very hot OATs the fuel air mixture can be heated to the point that it explodes during the compression stroke. This is known as detonation.
- Why is there a maximum oil temperature?
As oil heats up its viscosity becomes runnier. Above a certain temperature it will be too thin to do its job effectively.
- What are the cockpit indications of a an alternator failure?
A reading of zero or negative reading on the ammeter/voltmeter and illuminated alternator warning light.
- What are the cockpit indications of a magneto failure?
What actions should be taken?
Loss of RPM, rough running.
Check that the primer is locked (can cause a drop in RPM if not secured), avoid using high power settings and assume the other magneto will fail at any time. If there is no airport in the immediate surrounds then perform the forced landing procedure
- What could be the problem if the brakes have a spongy feel?
‘Spongy’ brakes are indicative of air in the hydraulic lines, as air is compressible and hydraulic fluid is not.
- What could bet the possible problems if the oil temperature reads high and the oil pressure reads normal?
High oil temperature can indicate low oil level, broken oil cooler, broken oil temperature gauge or an overheating engine; however, if the oil was low the pressure gauge would be reading low or fluctuating, so that leaves the oil cooler, the gauge or the engine.
- Why is the use of the carburetor heat restricted to air operations?
Carburetor Heat is unfiltered so if used on the ground there is a risk of sucking contaminants into the cylinder.
- When is the use of carburetor heat on the ground acceptable?
If icing is present on the ground then this takes priority over the risk of contaminants. Also, Carburettor Heat is tested during run ups.
- What is an “alternate air”source and how does it differ from carburetor heat?
Alternate air is often found in fuel injected engines. It provides an alternate source of air in the event of the air filter becoming blocked. Carburettor Heat can be used to the same effect, but also doubles as an anti-icing control.
- What effect will the application of carburetor heat have on engine operation?
Carburettor Heat uses hot air from around the exhaust. Hot air is less dense so it will enrich the mixture and cause a slight drop in RPM.
- What effect will low suction have on the gyroscopic instruments?
Low suction will cause the gyroscopic instruments to be sluggish and unreliable.
- What instruments will be effected?
Instruments that use the vacuum system (AI, DG)
- What gyroscopic instruments will be effected by a loss of electrical power?
The Turn Coordinator
- Define the terms Accident and Incident. What are the reporting
Requirements?
O
- What are the reasons for and the general contents of the CARs,
COAs, AIP and ERSA?
The CARs (Civil Aviation Regulations) contain the rules and regulations that govern aviation in Australia. It describes the scope that encompasses aviation. It is split into two parts, the CAR 1988 contains; Administration, Airworthiness, Maintenance, Licensing, Aerodromes, Rules of the Air, Operations and Prosecutions. The CASR (Civil Aviation Safety Regulations) contains; Rule enforcement, Aircraft Registration, Medical Certificates, Dangerous Goods and Air Traffic Services.
The CAOs (Civil Aviation Orders) are the next step down and contain information that is of greater relevance to us as pilots. Items that can be found in the CAOs include: Air Service Operations, Carriage of Dangerous Goods, License Ratings, Flight Time Limitations, Flying School Licenses, Safety Precautions.
The AIP (Aeronautical Information Publication) is the next step down again. It contains information only relevant to flying the aeroplane. Items that are found in the AIP include: Information on charts, Sunrise/Sunset Tables, Air Traffic Services, Communication Services, Search and Rescue, Operations in Controlled Airspace, General Operation Requirements, Flight Planning, Air Traffic Incidents, Interpreting Weather, Aerodrome Descriptions, Markings and Lighting. Additionally the AIP contains SUP (supplementary) information that is released ahead of major events (wings over wagga etc). The AIP is carried with us during navigational flights.
The ERSA (En-Route Supplement Australia) contains information on all the licensed aerodromes in Australia as well as restricted airspace information and an emergency survival guide. The ERSA must be carried with us if we are flying to an unfamiliar aerodrome.
- State
The minimum VMC for flight in all airspace.
CLASS D
CLASS G
CLASS E
CLASS D
CLASS G
CLASS E
- State the limitations imposed on a holder of a PPL?
A private pilot (aeroplane) licence authorises the holder of the licence:
(a) to fly an aeroplane as pilot in command, or as copilot, while the aeroplane is engaged in a private operation; and (b) to fly an aeroplane as pilot in command while the aeroplane is engaged in flying training operations for the purpose of increasing the holder’s flying skill. (1) Subject to subregulation (2), a private pilot (aeroplane) licence does not authorise the holder of the licence to fly an aeroplane as pilot in command, or as copilot, unless the holder also holds: (a) a type endorsement or class endorsement; and (b) if the aeroplane has a special design feature—a special design feature endorsement; that authorise the holder to fly the aeroplane in that capacity. (2) A private pilot (aeroplane) licence authorises the holder of the licence to fly an aeroplane without holding an aircraft endorsement for the aeroplane: (a) in dual flying—for the purpose of satisfying the requirements for the issue of an aircraft endorsement for the aeroplane; or (b) in any capacity—for the purpose of: (i) testing the aeroplane; or (ii) carrying out an experiment in relation to the aeroplane; if CASA has given the holder permission under subregulation 5.50(1) to fly the aeroplane in those circumstances; or (c) as pilot in command—for the purpose of satisfying the requirements for the issue of an aircraft endorsement for the aeroplane if: (i) the aeroplane is a single place aeroplane; and (ii) CASA has given the holder permission under subregulation 5.23(5) to fly the aeroplane