Exam 3: Commercial 321 Test Review

C172 Engine
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Why is the prop twisted?for uniform thrustWhat does manifold pressure tell me?the pressure of the air in the manifold (the tube that takes air from the outside into the engine)What is the way to control a turbo charger?the waste gate. (Control is accomplished by means of the waste gate -Spring holds it open, engine oil pressure forces it closed)Turbo charger vs super chargerTurbo is powered by exhuast gas and is air driven. The super charger has a mechanical linkage to the engine (belt or chain drive).Types of propellersfixed/constant and variable/controllableTypes of Fixed pitch propellersclimb prop and cruise propGeometric PitchThe theoretical distance a propeller should advance in one revolution.Effective Pitchthe distance a propeller actually advances through the airPropeller Pitchthe difference between geometric and effective pitchDetonation(Multiple flame fronts) Causes: Too lean a mixture Fuel grade too low Excessive heat (climbing too slow A/S) Compression ratio too highPre-ignition(Uncontrolled firing)i.e. before the power stroke▫ Causes: Residual hot spot, Spark Plugs in a "glowing" state as a result of detonation,How to fix/ recover from preignition and detonationPromote cooling of the engine: ▫Reducing power ▫Enriched the mixture ▫Opening Cowl Flaps (if equipped)What then affects performance?Air DensityGreater air density _____________ performance -why?Increases: Increased Propeller efficiency Increased Lift due to more air molecules over the wing Increased Engine performance -more air to mix to burn.Turbo chargers spin at an incredible _____________________ rpm in cruise75,000 to 150,000 rpmHow many general kinds of turbo chargers? What are they/ what makes them different?‱Two general kinds ▫Normalizing maintain sea level pressure up to the critical altitude (30in) ▫Boosting raises manifold pressure (35-45) (Requires lower compressions and intercooling)Types of waste gates?Manual: ▫Separate lever to control waste gate ▫Higher workload for the pilot Automatic: ▫Relies on oil pressure and an absolute pressure controller (APC) ▫Limits amount of MP when throttle is opened ▫Frees the pilot of "concentrated" monitoringWhen you compress a gas . . . it _____________. So..‱It heats up: (a lot) ‱For this reason, most engines have a pressure ratio limit ‱Becomes critical at higher altitudes ‱Heated gases decrease detonation limitBecause of heating most engines have anintercooler (alos known as radiator or heat exchanger) -located between throttle and MP gauge -A good intercooler can lower induction air by as much as 100 degrees FIssues with Turbo Chargers‱Higher operating temperatures ‱Higher maintenance costs ‱Higher initial acquisition costs ‱Higher overhaul costsRPM is maintained by way of theprop governorFuel/Air mixture is maintained by thethrottleRange of possible blade angles is called the.. (and is defined by the..)propeller's governing range (Defined by the blade's high and low angle pitch stops)Engines last longer -with reduced RPM settings. Why?▫By cruising at 2100 RPM instead of 2350 RPM over the course of 1,000 hours, each engine saves 15 million crank rotations, 7 million cam rotations, and 75 million piston reciprocations!When reducing power, propellers...Propellers operate more efficiently. ▫The slower the prop turns, the less energy is wastedComponents of the fuel injection system‱Fuel Tank ‱Auxiliary fuel pump ‱Engine driven fuel pump ‱Fuel control unit ‱Fuel manifold valve ‱Fuel discharge nozzles ‱Fuel flow indicatorAdvantages of a fuel injection system‱Reduction in evaporative icing ‱Better fuel flow ‱Faster throttle response ‱Precise control of mixture ‱Better fuel distribution ‱Easier cold weather startsDisadvantages of a fuel injection system‱Difficulty in starting a hot engine. ‱Vapor locks during ground operations on hot days. ‱Problems associated with restarting an engine that quits because of fuel starvationTypical aircraft battery systems are ___ or ___volt12 or 24 voltAircraft Electrical Systems Purpose1.Generate 2.Regulate 3.DistributeThe battery is used to...To supply power to starter and, if the alternator fails, power the electrical equipment.Ammeter shows thestate of Charge/Discharge on the BatteryLoad Meter shows theelectrical LOAD on the systemWhat are the 2 rocker switches on the master for?‱one for the alternator ‱one for the batteryWhat is the role of the Fuses and Circuit BreakersProtect electrical circuits.AC No: 120-80A says resetting popped circuit breakers in flightYou should not reset a tripped circuit breaker in flight unless doing so is consistent with explicit procedures specified in the approved operating manual used by the flight crew or unless, in the judgment of the captain, resetting the circuit breaker is absolutely necessary for the safe completion of the flight.How does a Basic Hydraulic System work?‱A valve is opened, the hydraulic fluid flows into the actuator and presses against the piston, causing it to move and in turn move the attached control surfacePascal's Law?A pressure applied to a confined fluid is transmitted with equal intensity throughout the fluid. Same pressure all throughout!Problems with Hydraulics‱Heavy ‱High maintenance ▫Adds cost and creates a logistics problem ‱Requires space (pumps, hydraulic lines, etc.) ‱BUT it is very powerfulTypes of Landing Gear?‱Fixed ‱Retractable ‱Castoring ‱SteerableElectric landing gear motors are often ______________.reversible (Hydraulic systems often do not have reversible motors but directional valves.)Reasons why the gear horn goes off▫1. Gear handle UP and A/C is on the GND ▫2. Throttle is retarded and gear is UP ▫3. Flaps extended below 10 degw/ gear UPVlemaximum landing gear extended speedVlomaximum landing gear operating speedEmergency gear extension 3 system typeshand crank systems free fall system CO2 pressurized systemsMemory aid to ensure the gear is downGUMPS: Gas-on Undercarraige Mixture Props SwitchesThree basic configurations of oxygen systems?▫Continuous-flow (100% O2) ▫Diluter-demand (O2 and air OR 100% O2) ▫Pressure-demand (O2 under positive pressure)Continuous-flow-up to 25,000 (switch from cannula to mask above 18,000)Diluter-demand-up to approx. 40,000▫Ambient air up to 8,000▫100% delivered above 33,000▫Only flows on inhalationPressure-demand-34,000 CPA and above delivered under pressureThree types of Continuous-flow oxygen systems?▫Constant flow ▫Adjustable-flow ▫Altitude-compensated -most popularOxygen is stored onboard in1.High/low pressure cylinders (pilots, walk around bottles) 2.Chemical Oxygen Generators (pax) 3.LOXCabin differential pressure is the pressure difference betweenambient air and the air inside the pressure vesselThree instruments used in conjunction with the pressure controller:▫Cabin Differential Pressure Gauge (PSID) ▫Cabin Altimeter (feet) ▫Cabin rate-of-climb instrument (Feet/minute)Heat exchanger (Pressurization System Component)used to cool the hot pressurized air to a usable temperatureOutflow Valve (Pressurization System Component)primary cabin pressure control, regulates the amount of pressurized air that is allowed to exit the cabinSafety Valve /positive pressure relief valve (Pressurization System Component)prevents cabin over-pressurization by opening automatically at a predetermined pressureNegative Pressure-Relief Valve (Pressurization System Component)▫Prevents cabin pressure from going below that of the ambient airDump Valve (Pressurization System Component)▫Releases all cabin pressure when aircraft lands ▫Often controlled by landing gear squat switchReciprocating engines can pressurize cabin air through the use of:▫Superchargers ▫Turbochargers ▫Engine-driven air pumpsThe use of superchargers and turbochargers for pressurized air may introducefumes and oil into the cabin airIndependent cabin compressors are driven by either:▫The engine accessory section ▫Turbine-engine bleed airBleed air must be cooled or refrigerated for..cabin airExplosive decompressions (AC 61-107B):(less than 0.5 second and can cause bodily damage)Rapid decompressions(1-10/12 sec.)Deice vs Anti-ice systemsDeice-designed to remove ice after it has formed Anti-icesystem is used to prevent ice from formingDeice systems examples‱Carb Heat ‱Wing boots ‱Tail bootsAnti-ice systems examples▫Pitot Heat ▫Alcohol sprayers -windshield, prop blades ▫Electrically Heated -wing boots, prop blades, windshieldsRemember, an aircraft can be equipped with deice and anti-ice equipment, but notbe certificated to fly into known icing conditions.Windshield Ice Control▫Alcohol ▫ThermalPropeller Ice Control▫Thermal ▫AlcoholProblems with cold weather flying▫CO Posioning ▫Super-cooling the engines ▫Indistinguishable runways ▫Pre/Post-Flight Analysis (it's cold) -therefore let the FO do it! ▫Survival and Emergencies ▫OtherSurvival is: (%)▫80% mental▫10% equipment▫10% skills▫Number 1 enemy is ▫Number 2 enemy is ▫Number 3 enemy is ▫Number 4 enemy is▫Number 1 enemy is yourself. ▫Number 2 enemy is injuries. ▫Number 3 enemy is temperature. ▫Number 4 enemy is disease.With a high density altitude..‱Less engine power (less oxygen molecules) ‱Less propeller thrust and less lift ‱Lean non-turbo for best power before Takeoff ‱Use Aircraft POH or AFM performance tablesTakeoff Roll Increases with:‱Higher density altitude ‱Tailwind component / local terrain effect ‱Rough or soft runway surfaceNight flying can be5 time more dangerous than day flyingFAR 91.205 (c): requires additional equipment for night flying▫Anti-collision and Position lights, Electrical source, and Spare FusesPosition lights required: FAR 91.209▫Sunset to sunriseLogging night landings for carrying passengers: FAR 61.57b▫1 Hour after sunset/1 hour before sunriseLogging night landings for carrying passengers: FAR 61.57b▫End of evening civil twilight to beginning of morning civil twilightIllusions leading to spatial disorientation‱The Leans ‱Coriolis Illusion ‱Graveyard Spin ‱Graveyard Spiral ‱Somatogravic Illusion ‱Inversion Illusion ‱Elevator Illusion ‱False Horizon ‱AutokinesisWhat is "Aeronautical Decision Making"?Systematic approach to the mental process used by pilots to consistentlydetermine the best course of action in response to a given set of circumstances -AC 60-22It is estimated that approximately 80 percent of all aviation accidents are related tohuman factors... (PHAK 2-2)Risk Management Process‱Identify ‱Assess ‱Analyze ‱Make Control Decisions ‱Use Controls ‱Monitor Results4 -Fundamental Principles of Risk Management1.Accept no unnecessary risk. Flying is not possible without risk, but unnecessary risk comes without a corresponding return. 2.Make risk decisions at the appropriate level. Risk decisions should be made by the person who can develop and implement risk controls. 3.Accept risk when benefits outweigh dangers (costs). In any flying activity, it is necessary to accept some degree of risk. 4.Integrate risk management into planning at all levels.5 Hazardous Attitudesanti-authority macho resignation impulsivity invulnerabilityMacho (5 Hazardous Antidotes)I can do itdoAnti-Authority (5 Hazardous Antidotes)dont tell meResignation (5 Hazardous Antidotes)whats the useInvulnerability (5 Hazardous Antidotes)it wont happen to meImpulsivity (5 Hazardous Antidotes)do it quicklyCOA/SACourse of Action/Situational Awareness"DECIDE" ModelDetect Estimate Choose Identify Do EvaluateADM/ The 3-P Model‱Perceive ▫Gather all available information ‱Process ▫Organize, match against prior experience ‱Perform ▫Decide a COA (or decide to do nothing)The 5 Ps Check▫The Plan ▫The Plane ▫The Pilot ▫The Passengers ▫The ProgrammingWhat airport beacon is green and white?for civilian land airportsWhat airport beacon is white and yellow?for a water airportWhat airport beacon is white, yellow, green?heliportWhat airport beacon has two quick white flashes alternating with a green flash?military airportWhat is a "TCDS?"-tells you basic designs and parameters. If you build it that way you get an airworthy/certified aircraft and you get airworthiness certificate if built in accordance with the TCDS. Or properly altered condition (along with form 337). Or POH is TCDS. & MUST be in a condition SAFE for flight.What are the component parts of a turbo-charger that we discussed in class?-intake attached to exhaust, impeller/compressor, inner cooler, waste gate (on the exhaust side of the system- if you didn't have one you wouldn't have pressure build up- if you didn't have one, you couldn't control the flow of exhaust gas which... spins the turbine. If you don't have a waste gate you cant control the RPM aka the turbine/ the turbo charger.What controls MP and what controls RPMs with a constant speed propeller?"-throttle controls Manifold pressure in regular. RPM is propeller control. Mixture controls mixture (and rpm if idle)The typical electrical systems for airplanes are ____ & ____ volt systems with ___ & ___ batteries?Volts: 28 & 14 Batteries: 24 & 12 Our Plane: 28 volt with 24 volt batteryWith only 2 green landing gear indicator lights, what is normally part of the troubleshoot process.-take the light bulbs out and switch and see if it's a bulb problem, use mirrors if installed. Check circuit breakers. Do checklists. (if your gear handle is down, the stall warning horn would think the gear is down no matter where the gear actually is; ex if its up and says down or if its down not up)How would one manage carb ice?-carb heat on. (get to warmer climates) can get them up to 100degrees and as low as 50% humidityWhy do we feather in a multi engine aircraft?-increase range, reduce dragIf we lose an engine in a complex single enginge? If we feather would we reduce drag?-YesSo why don't we feather it (a single engine airplane)?For this ex. we are completely out of gas -because BY DESIGN it does not feather.If you lose oil in prop hub in a multi... WHY does it feather**If you lose oil in the prop hub in the multi- it with feather BECAUSE they designed it that way.. it decreases drag for us. It was by design.Beta Quadrant:(king air has them) as it goes thru the cycle and has reverse thrustWhen do we lean the mixture when departing from higher elevation airports-POH says airports above 3000ft