Airplane systems Flashcards

Question

Describe the AIR DATA COMPUTER (GDC).

Answer 1

AIR DATA COMPUTER (GDC) The Air Data Computer (ADC) compiles information from the airplane's pitot-static system. The ADC unit is mounted in the tailcone. An outside air temperature probe, mounted on top of the cabin, is connected to the ADC. The ADC calculates pressure altitude, airspeed, true airspeed, vertical speed and outside air temperature.

Answer 2

ENGINE MONITOR (GEA) The Engine Monitor is responsible for receiving and processing the signals from all of the engine and airframe sensors. It is connected to all of the CHT measuring sensors, EGT sensors, RPM, fuel flow and to the fuel gauging system. This unit transmits this information to the engine display computers.

Answer 3

TRANSPONDER(GTX) The full-featured Mode S transponder provides Mode A, C and S functions. Control and operation of the transponder is accomplished using the PFD. The transponder unit is mounted in the tailcone avionics racks.

Answer 4

XM WEATHER AND RADIO DATA LINK (GDL) The XM weather and radio data link provides weather information and digital audio entertainment in the cockpit. The unit is mounted in the tailcone. This unit communicates with the MFD on the high-speed data bus. XM weather and XM radio operate in the S-band frequency range to provide continuous uplink capabilities at any altitude throughout North America. A subscription to the XM satellite radio service is required for the XM weather and radio data link to be used.

Answer 5

CONTROL WHEEL STEERING (CWS) The Control Wheel Steering (CWS) button, located on the pilot's control wheel, immediately disconnects the pitch and roll servos when activated. Large pitch changes while using CWS will cause the airplane to be out of trim. Retrim the airplane as necessary during CWS operation to reduce control forces or large pitch oscillations that may occur after releasing the CWS button.

Answer 6

AVIONICS COOLING FANS Four DC electric fans provide forced air and ambient air circulation cooling for the G1000 avionics equipment. A single fan in the tailcone provides forced air cooling to the integrated avionics units and to the transponder. A fan located forward of the instrument panel removes air from between the firewall bulkhead and instrument panel, directing the warm air up at the inside of the windshield. Two additional fans blow air directly onto the heat sinks located on the forward sides of the PFD and MFD. Power is provided to these fans when the MASTER (BAT) switch and the AVIONICS (BUS 1 and BUS 2) switch are all ON. NOTE : None of the cooling fans will operate when the essential bus avionics equipment is being powered by the standby battery.

Answer 7

ANTENNAS Two dual-mode VHF COM/GPS antennas are mounted on the top of the cabin. The COM 1/GPS 1 antenna is mounted on the right side and the COM 2/GPS 2 antenna is mounted on the left side. They are connected to the two VHF communication transceivers and the two GPS receivers in the integrated avionics units. The GDL antenna is also mounted on the top of the cabin. It provides a signal to the GDL-69A XM Data Link receiver. A blade-type navigation antenna is mounted on either side of the vertical stabilizer. This antenna provides VOR and glideslope signals to the VHF navigation receivers contained in the integrated avionics units. The marker beacon antenna is mounted on the bottom of the tailcone. It provides the signal to the marker beacon receiver located in the audio panel. The transponder antenna is mounted on the bottom of the cabin and is connected to the Mode S transponder by a coaxial transmission cable. The Bendix/King Distance Measuring Equipment (DME) antenna (if installed) is mounted on the bottom of the tailcone and is connected to the Bendix/King DME receiver by a coaxial cable.

Answer 8

STATIC DISCHARGERS Static dischargers are installed at various points throughout the airframe to reduce interference from precipitation static. Under some severe static conditions, loss of radio signals is possible even with static dischargers installed. Whenever possible, avoid known severe precipitation areas to prevent loss of dependable radio signals. If avoidance is impractical, minimize airspeed and anticipate temporary loss of radio signals while in these areas. Static dischargers lose their effectiveness with age, and therefore, should be checked periodically, at least at every annual inspection, by a qualified technician.

Answer 9

CABIN FIRE EXTINGUISHER A portable Halon 1211 (Bromochlorodifluoromethane) fire extinguisher is installed in a holder on the floorboard between the front seats to be accessible in case of fire. The extinguisher is classified 5B:C by Underwriters Laboratories. The extinguisher should be checked prior to each flight to ensure that the pressure of the contents, as indicated by the gage at the top of the extinguisher, is within the green arc (approximately 125 psi) and the operating lever lock pin is securely in place. To operate the fire extinguisher: 1. Loosen retaining clamp(s) and remove extinguisher from bracket. 2. Hold extinguisher upright, pull operating ring pin, and press lever while directing the liquid at the base of the fire at the near edge. Progress toward the back of the fire by moving the nozzle rapidly with a side-to-side sweeping motion. WARNING VENTILATE THE CABIN PROMPTLY AFTER SUCCESSFULLY EXTINGUISHING THE FIRE TO REDUCE THE GASES PRODUCED BY THERMAL DECOMPOSITION. 3. The contents of the cabin fire extinguisher will empty in approximately eight seconds of continuous use. Fire extinguishers should be recharged by a qualified fire extinguisher agency after each use. After recharging, secure the extinguisher to its mounting bracket.

Answer 10

CARBON MONOXIDE DETECTION SYSTEM The carbon monoxide (CO) detection system consist of a single detector located behind the instrument panel, powered by the airplane's DC electrical system and integrated in the Garmin G1000 system with a warning annunciation and alert messages displayed on the PFD. When the CO detection system senses a CO level of 50 parts-per-million (PPM) by volume or greater the alarm turns on a flashing warning annunciation, CO LVL HIGH, in the annunciation window on the PFD with a continuous tone until the PFD softkey below WARNING is pushed. It then remains on steady until the CO level drops below 50 PPM and automatically resets the alarm. If the CO system detects a problem within the system that requires service, a CO DET SRVC message is displayed in the alerts window of the PFD. If there is an interface problem between the G1000 system and the CO system a CO DET FAIL message is displayed in the alerts window of the PFD.

Answer 11

The four strokes are: Intake - fuel mixture is drawn into cylinders by downward stroke. Compression - mixture is compressed about a four stroke. Power - spark ignites mixture forcing piston downward and producing power. Exhaust - Burned gases pushed out of cylinder by upward stroke.

Answer 12

Fuel injectors have replaced carburetors in some airplanes. In a fuel injection system, the fuel is normally injected into the system either directly into the cylinders or just a head of the intake valves; whereas in a carbureted system, the fuel enters the airstream at the throttle valve. There are several types of fuel injection systems in use today, and though there are variations in design, the operational methods are generally simple. Most designs incorporate an engine driven fuel pump, fuel/air control unit, fuel manifold valve, discharge nozzles, auxiliary fuel pump, and fuel pressure/flow indicators.

Answer 13

a) Reduction in evaporatorative icing. b) Better fuel flow. c) Faster throttle response. d) Precise control of mixture. e) Better fuel distribution. f) Easier cold weather starts.

Answer 14

a) Difficulty in starting a hot engine. b) Vapor locks during ground operation on hot days. c) Problems associated with restarting an engine that quit because of fuel starvation.

Answer 15

It is a device which opens, either automatically or manually, to allow induction airflow to continue should the primary induction air opening become blocked. In the event of an impact as accumulation over normal engine induction sources, carburetor heat (carbureted engines) or alternate air (fuel injected engines) should be selected. On some fuel injected engines, an alternate air source is automatically activated with blockage of the normal air source.

Answer 16

Vapor lock is a condition in which AVGAS vaporizes in the fuel liner other components between the fuel tank and the carburetor. This typically occurs on warm days on aircraft with engine driven fuel pumps that suck fuel from the tanks. Vapor locks and be caused by excessively hot fuel, low pressure, or excessive turbulence of the fuel traveling through the fuel system. In each case, liquid fuel vapor rises prematurely and blocks the flow of liquid fuel to the carburetor. Various steps can be taken to prevent vapor lock. The most common is the use of boost pumps located in the fuel tank that force pressurized liquid fuel to the engine.

Answer 17

The throttle allows the pilot to manually control the amount of fuel/air charge entering the cylinders. This in turn regulates the engine manifold pressure.

Answer 18

It regulates the fuel-to-air ratio. Most airplane engines incorporate a device called a mixture control, by which the fuel/air ratio can be controlled by the pilot during flight. The purpose of a mixture control is to prevent the mixture from becoming too rich at high altitudes, due to the decreasing air density. Leaning the mixture during cross-country flights of conserves fuel and provides optimum power.

Answer 19

Cowl flaps are located on the engine cowling and allow the pilot to control the operating temperature of the engine by regulating the amount of air circulating within the engine compartment. Cowl flaps may be manually or electrically activated and usually allow for a variety of flap positions.

Answer 20

Normally the cowl flaps will be in the “open” position in the following operations: a) During starting of the engine. b) While taxing. c) During takeoff and high-power climb operation. The cowl flaps may be adjusted in cruise for the appropriate cylinder head temperature. The cowl flaps should be in the “close” position in the following operations: a) During extended let-downs. b) Anytime excessive cooling is a possibility (I.e., approach to landing, engine-out practice etc.)

Answer 21

PROPELLER The airplane is equipped with a two bladed, fixed pitch, one-piece forged aluminum alloy propeller which is anodized to retard corrosion. The propeller is 76 inches in diameter.

Answer 22

The pitch of this propeller is fixed by the manufacturer and cannot be changed by the pilot. Two types of fix pitch propellers are: Climb propeller - has a lower pitch, therefore less drag. Results in higher RPM and more horsepower being developed by the engine; increases performance during takeoffs and climbs, but decreases performance during cruising flight. Cruise propeller - has a higher pitch, therefore more drag. Results and lower RPM and less horsepower capability; decreases performance during takeoffs and climbs, but increases efficiency during cruising flight.

Answer 23

An airplane equipped with a constant speed propeller is capable of continuously adjusting the propeller blade angle to maintain a constant engine speed. For example, if engine RPM increases as a result of a decreased load on the engine (descent), the system automatically increases the propeller blade angle (increasing air load) until the RPM has returned to the preset speed. The propeller governor can be regulated by the pilot with a control in the cockpit, so that any desired blade angle setting ( within its limits) and engine operating RPM can be obtained, thereby increasing the airplane’s efficiency in various flight conditions.

Answer 24

Flight Controls Aircraft flight control systems consist of primary and secondary systems. Primary: ailerons, elevator (or stabilator), and rudder Secondary: Wing flaps, leading edge devices, spoilers, trim systems The secondary control system and improve the performance characteristics of the airplane or relieve the pilot of excessive control forces.

Answer 25

The propeller control regulates propeller pitch and engine rpm as desired for a given flight condition. The propeller control adjusts a propeller governor which establishes and maintains the propeller speed, which in turn maintains the engine speed.

Answer 26

The propeller control regulates propeller pitch and engine RPM as desired for a given flight condition. The propeller control adjusts a propeller governor which establishes and maintains the propeller speed, which in turn maintains the engine speed.

Answer 27

A low pitch, high RPM setting produces maximum power and thrust. The low blade angel keeps the angle of attack small and efficient with respect to the relative wind. A the same time, it allows the engine to handle a smaller mass of air per revolution. This light load allows the engine to turn at high RPM and to convert the maximum amount of fuel into heat energy in a given time. The high RPM also creates maximum thrust because the mass of air handled per revolution is small, the number of revolutions per minute is many, the slipstream is high, and the airplane speed is low.

Answer 28

The propeller governor, with the assistance of a governor pump, controls the flow of engine oil to or from a piston in the propeller hub. When the engine oil, under high pressure from the governor pump, pushes the piston forward, the propeller blades are twisted toward a high pitch/low RPM condition. When the engine oil is released from the cylinder, centrifugal force, with the assistance of an internal spring, twists the blades towards a low pitch/high RPM condition.

Answer 29

Excessive manifold pressure raises the cylinder compression pressure, resulting in high stresses within the engine. Excessive pressure also produces high engine temperatures. A combination of high manifold pressure and low RPM can induce damaging detonation; however, it is a fallacy that (in non-turbocharged engines) the manifold pressure in inches of mercury (inches Hg) should never exceed RPM in hundreds for cruise power settings. The cruise power charts in the AFM/POH should be consulted when selecting cruise power settings. Whatever the combinations of RPM and manifold pressure listed in these charts - they have been flight tested and approved by the airframe and powerplant engineers for the respective airframe and engine manufacturer.

Answer 30

Generally, the oil pressure used for pitch changes comes directly from the engine lubricating system. When a governor is employed, engine oil is used and the oil pressure is usually boosted by a pump that is integrated with the propeller governor

Answer 31

The fuel system in a 172S consists of the following: a. two vented integral fuel tanks b. a three-position fuel selector valve c. fuel reservoir tank d. an electrically-driven auxiliary fuel pump e. fuel shutoff valve f. fuel strainer Engine mounted portion: g. engine-driven fuel pump h. a fuel/air control unit i. a fuel flow transducer j. a fuel distribution valve (flow divider) k. fuel injection nozzles Fuel flows by gravity from the two wing tanks to a three-position fuel selector valve, labeled BOTH, RIGHT and LEFT, and on to the fuel reservoir tank. From the fuel reservoir tank, fuel flows through the electrically-driven auxiliary fuel pump, through the fuel shutoff valve, the fuel strainer, and to the engine-driven fuel pump. From the engine-driven fuel pump, fuel is delivered to the fuel/air control unit on the bottom of the engine. The fuel/air control unit (fuel servo) meters fuel flow in proportion to induction air flow. After passing through the control unit, metered fuel goes to a fuel distribution valve (flow divider) located on the top of the engine. From the fuel distribution valve, individual fuel lines are routed to air bleed type injector nozzles located in the intake chamber of each cylinder.

Answer 32

The auxiliary fuel pump is used primarily for priming the engine before starting. Priming is accomplished through the fuel injection system. The engine may be flooded if the auxiliary FUEL PUMP switch is accidentally placed in the ON position for prolonged periods, with MASTER Switch ON and mixture rich, with the engine stopped. The auxiliary fuel pump is also used for vapor suppression in hot weather. Normally, momentary use will be sufficient for vapor suppression; however, continuous operation is permissible if required. Turning on the auxiliary fuel pump with a normally operating engine-driven fuel pump will result in only a very minor enrichment of the mixture. It is not necessary to operate the auxiliary fuel pump during normal takeoff and landing, since gravity and the engine-driven fuel pump will supply adequate fuel flow. In the event of failure of the engine-driven fuel pump, use of the auxiliary fuel pump will provide sufficient fuel to maintain flight at maximum continuous power. Under hot day, high altitude conditions, or conditions during a climb that are conducive to fuel vapor formation, it may be necessary to utilize the auxiliary fuel pump to attain or stabilize the fuel flow required for the type of climb being performed. In this case, turn the auxiliary fuel pump on, and adjust the mixture to the desired fuel flow. If fluctuating fuel flow (greater than 1 GPH) is observed during climb or cruise at high altitudes on hot days, place the auxiliary fuel pump switch in the ON position to clear the fuel system of vapor. The auxiliary fuel pump may be operated continuously in cruise.

Answer 33

When the fuel selector valve is placed in the BOTH position, while in cruise flight, unequal fuel flow from each tank may occur if the wings are not maintained exactly level. Unequal fuel flow can be detected by one fuel tank indicating more fuel than the other on the L FUEL and R FUEL indicators. The resulting fuel imbalance can be corrected by turning the fuel selector valve to the fuel tank indicating the highest fuel quantity. Once the L FUEL and R FUEL indicators have equalized, position the fuel selector valve to the BOTH position. During cruise flight, with the fuel selector valve on "Both," unequal fuel flow may occur if the wings are not consistently kept level during the flight. This will result in one wing being heavier than the other. A fuel selector valve with the left/right option allows a pilot to control the situation by selecting the tank on the heavier wing and remaining on that tank until both tanks contain approximately the same amount of fuel.

Answer 34

The fuel venting system consists of an interconnecting vent line between the fuel tanks and a check valve equipped overboard vent in the left fuel tank assembly. The overboard vent protrudes from the bottom surface of the left wing, just inboard of the wing strut upper attachment point. The fuel filler caps are vacuum vented; the fuel filler cap vents will open and allow air to enter the fuel tanks in case the overboard vents become blocked.

Answer 35

Fuel system venting is essential to system operation. Complete blockage of the fuel venting system will result in decreasing fuel flow and eventual engine stoppage. The fuel filler cap vents will open and allow air to enter the fuel tanks in case the overboard vents become blocked.

Answer 36

80 - Red 100 - Green 100LL - Blue Jet A - Colorless or straw

Answer 37

5 under each wing; 3 under the fuel selector valve

Answer 38

Fuel quantity is measured by two fuel quantity sensors, one in each fuel tank, and is displayed on the EIS pages.

Answer 39

The fuel quantity indicator shows the fuel available in the tank up to the limit of the sensor measurement range. At this level, additional fuel may be added to completely fill the tank, but no additional movement of the indicator will result. The limit for sensor measurement range is approximately 24 gallons and is indicated by the maximum limit of the green band. When the fuel level decreases below the maximum limit of the fuel sensor, the fuel quantity indicator will display fuel quantity measured in each tank. A visual check of each wing tank fuel level must be performed prior to each flight. Compare the visual fuel level and indicated fuel quantity to accurately estimate usable fuel.

Answer 40

The engine utilizes a full pressure, wet sump type lubrication system with aviation grade oil as the lubricant. The capacity of the engine sump, located on the bottom of the engine, is eight quarts with one additional quart contained in the engine oil filter. Oil is drawn from the sump through a filter screen on the end of a pickup tube to the engine driven oil pump. Oil from the pump passes through a full-flow oil filter, a pressure relief valve at the rear of the right oil gallery, and a thermostatically controlled remote oil cooler. Oil from the remote cooler is then circulated to the left oil gallery. The engine parts are then lubricated by oil from the galleries. After lubricating the engine, the oil returns to the sump by gravity. The filter adapter in the full-flow filter is equipped with a bypass valve which will cause lubricating oil to bypass the filter in the event the filter becomes plugged, or the oil temperature is extremely cold.

Answer 41

The engine should not be operated on less than five quarts of oil. To minimize loss of oil through the breather, fill to eight quarts for normal flights of less than three hours. For extended flight, fill to eight quarts (dipstick indication only).

Answer 42

Oil temperatures - 75-245°F Oil pressure: 0-20 PSI red band 50-90 PSI green band - normal operating range 115-120 PSI red band With the engine at normal operating oil temperature, and engine speed at or close to idle, oil pressure below the green band, but above the lower red band, is acceptable.

Answer 43

Mineral oil - Also know as non-detergent oil; contains no additives. This type of oil normally used after an engine overhaul or when an aircraft engine is new; normally used for engine break-in purposes. Ashless dispersant - Mineral oil with additives; high antiwear properties along with multi-viscosity (ability to perform in wide range of temps). Also picks up contamination and carbon particles and keeps them suspended so that buildups and sludge do not form in the engine.

Answer 44

MIL-L-22851 or SAE J1899 Ashless Dispersant Oil SAE Grade Summer (above 60°F) use SAE 40 or SAE 50; Winter use generally SAE 20W-50 More specifically for C172S: Above 27°C (80°F) - 60 grade Above 16°C (60°F) - 40 or 50 grade -1°C (30°F)to 32°C (90°F) - 40 grade -18°C (0°F) to 21°C (70°F) - 30,40 or 20W-40 Below -12°C (10°F) - 30 or 20W-30 -18°C (0°F) to 32°C (90°F) - 20W-50 or 15W-50 All Temperatures - 15W-50 or 20W-50

Answer 45

The airplane is equipped with a 28-volt direct current (DC) electrical system. A belt-driven 60 ampere alternator powers the system. A 24-volt main storage battery is located inside the engine cowling on the left firewall. The alternator and main battery are controlled through the MASTER switch found near the top of the pilots switch panel.

Answer 46

A 24-volt main storage battery is located inside the engine cowling on the left firewall.

Answer 47

Most of the electrical circuits in an airplane are protected from an overload condition by either circuit breakers or fuses or both. Circuit breakers perform the same function as fuses except that when an overload occurs, a circuit breaker can be reset.

Answer 48

A bus bar is used as a terminal in the aircraft electrical system to connect to the main electrical system to the equipment using electricity as a source of power. This simplifies the wiring system and provides a common point from which voltage can be distributed throughout the system.

Answer 49

Normally the following: Radio equipment Turn coordinator Fuel gauges Pitot Heat Landing Light Taxi Light Strobe Lights Interior Lights Instrument Lights Position Lights Flaps Stall warning system (maybe - yes in TH) Oil temp gauge Cigarette lighter (maybe) Starting motor Electric fuel pump

Answer 50

It shows if the alternator/generator is producing an adequate supply of electrical power to the system by measuring the amperes of electricity, and also indicates whether the battery is receiving an electrical charge. If the needle indicates a plus value, it means that the battery is being charged. if the needle indicates a minus value, it means that the generator or alternator output is inadequate and energy is being drawn from the battery to supply the system.

Answer 51

A voltage regulator controls the rate of charge to the battery by stabilizing the generator or alternator electrical output. The generator/alternator voltage output is usually slightly higher than the battery voltage. For example, a 12-volt battery would be fed by a generator/alternator system of approximately 14 volts. The difference in voltage keeps the battery charged.

Answer 52

Engine ignition is provided by two engine-driven magnetos, and two spark plugs per cylinder. The ignition system is completely independent of the aircraft electrical system. The magnetos are self-contained units supplying electrical current without using an external source of power. However, before they can produce current, the magnetos must be actuated as the engine crankshaft is rotated by some other means. To accomplish this, the aircraft battery furnishes electrical power to operate a starter which, through a series of gears, rotates the engine crankshaft. This in turn actuates the armature of the magneto to produce the sparks for ignition of the fuel in each cylinder. After the engine starts, the starter system is disengaged and the battery no longer contributes to the actual operation of the engine.

Answer 53

a. Increased safety - in case one system fails the engine may be operated on the other until a landing is safely made. b. More complete and even combustion of the mixture, and consequently improved engine performance; i.e., the fuel/air mixture will be ignited on each side of the combustion chamber adn burn toward the center.

Answer 54

Windshield defrost air is also supplied by two ducts leading from the cabin manifold to defroster outlets near the lower edge of the windshield. Two knobs control sliding valves in either defroster outlet to permit regulation of defroster airflow.

Answer 55

The avionics power switch controls power from the primary bus to the avionics bus. The circuit is protected by a combination power switch/circuit breaker. Aircraft avionics are isolated from electrical power when the switch is in the "Off" position. Also, if an overload should occur in the system, the avionics power switch will move to the "Off" position, causing an interruption of power to all aircraft avionics.

Answer 56

Static dischargers are installed on aircraft to reduce radio receiver interference caused by corona discharge, which is emitted from the aircraft as a result of precipitation static. Static dischargers, normally mounted on the trailing edges of the control surfaces, wing tips, and vertical stabilizer, discharge the precipitation static at points a critical length away from the wing and tail extremities where there is little or no coupling of the static into the radio antenna.

Answer 57

Attitude and Heading Reference System. Composed of three-axis sensors that provide heading, attitude, and yaw information for aircraft. AHRS are designed to replace traditional mechanical gyroscopic flight instruments and provide superior reliability and accuracy.

Answer 58

Air Data Computer. An aircraft computer that receives and processes pitot pressure, static pressure, and temperature to calculate very precise altitude, indicated airspeed, true airspeed, vertical speed, and air temperature.

Answer 59

Primary Flight Display. A display that provides increased situational awareness to the pilot by replacing the traditional six instruments with an easy-to-scan display that shows the horizon, airspeed, altitude, vertical speed, trend, trim, rate-of-turn, and more.

Answer 60

Multi-function Display. A cockpit display capable of presenting information (navigation data, moving maps, terrain awareness, etc.) to the pilot in configurable ways; often used in concert with the PFD.

Answer 61

Flight Director. An electronic flight computer that analyzes the navigation selections, signals, and aircraft parameters. It presents steering instructions on the flight display as command bars or crossbars for the pilot to position the nose of the aircraft over or follow.

Answer 62

Flight Management System. A computer system containing a database for programming of routes, approaches, and departures that can supply navigation data to the flight director/autopilot from various sources, and can calculate flight data such as fuel consumption, time remaining, possible range, and other values.

Answer 63

Terrain Awareness and Warning System. Uses the aircraft's GPS navigation signal and altimetry systems to compare the position and trajectory of the aircraft against a more detailed terrain and obstacle database. This database attempts to detail every obstruction that could pose a threat to an aircraft in flight.

Answer 64

A magnetometer is a device that measures the strength of the earth's magnetic field to determine aircraft heading; it provides this information digitally to the AHRS, which then sends it to the PFD.

Answer 65

In the event of a display failure, some systems offer a "reversion" capability to display the primary flight instruments and engine instruments on the remaining operative display.

Airplane systems Flashcards

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