Presentation on theme: "Cessna Single Engine Aircraft Maintenance"— Presentation transcript:
1Cessna Single Engine Aircraft Maintenance Compression Ignition Engine in the J182T AircraftCessna Single Engine Aircraft MaintenanceKevin Patrick – Cessna Field ServiceHello. I am Kevin Patrick from Cessna Fleet Programs, Wichita KS.I would like to thank Dan Daniel and the CAP National Headquarters staff for inviting me and giving me this opportunity to speak with you today.We will be discussing Compression Ignition, better known as Diesel, engines in in the Cessna J182T Skylane aircraft.Kevin Patrick – Cessna Fleet Programs
2Compression Ignition (Diesel) Technology Cessna J182T SMA Engine Course OutlineCompression Ignition (Diesel) TechnologyCessna J182T SMA EngineJ182T Engine IndicationFuel Cap ChangesJ182T Performance DataQuestions, Answers and Wrap-UpIn this presentation we will discuss:Basics of Compression Engine TechnologyThe SMA C305 engine installed in the J182T aircraftThe J182T EIS pagesJet A fuel cap changes andJ182T Performance DataWe will finish up with a review and Q&A. Feel free to ask questions during this presentation.
3Compression Ignition (Diesel) Technology Compression Ignition (C.I.), better known as “diesel” engines do not use an ignition system for combustion of fuel in the cylinders.C.I. Engines ingest air without fuel. When the air is compressed by the piston during the compression stroke, fuel is injected into the cylinder. The heat of the air compression process causes the fuel to combust spontaneously, this drives the piston downward and powers the engine.Combustion timing is controlled by the timing of fuel injection into the cylinder.The compression ignition engine, better known as a “diesel” engine, has the highest thermal efficiency of any regular internal or external combustion engine due to its very high compression ratio.In a compression ignition engine, only air is initially introduced into the combustion chamber. The air is then compressed with a compression ratio typically between 15:1 and 22:1 resulting in a 580 PSI pressure compared to about 200 psi in the gasoline engine. This high compression heats the air to about 1,022 °F. At about the top of the compression stroke, fuel is injected directly into the compressed air in the combustion chamber. This may be into a void in the top of the piston or a pre-chamber depending upon the design of the engine.The fuel injector ensures that the fuel is broken down into small droplets, and that the fuel is distributed evenly. The heat of the compressed air vaporizes fuel from the surface of the droplets. The vapor is then ignited by the heat from the compressed air in the combustion chamber, the droplets continue to vaporize from their surfaces and burn, getting smaller, until all the fuel in the droplets has been burnt. The rapid expansion of combustion gases then drives the piston downward, supplying power to the crankshaft.
4Compression Ignition (C.I.) Engine Technology Here is a recap of the combustion cycle process in the C.I. engine
8C.I. Engine AdvantagesC.I. engines have several advantages over gasoline engines:They burn less fuel than a petrol engine performing the same workThey have no high voltage electrical ignition systemThey generate less waste heat in cooling and exhaustThe carbon monoxide content of the exhaust is minimalJet A cylinder lubrication propertiesHere are a few advantages that the C.I. engine has over a normal “Avgas” powered engineThey burn less fuel than a petrol engine performing the same work, due to the engine's higher temperature of combustion and greater expansion ratio. Gasoline engines are typically 30% efficient while diesel engines can convert over 45% of the fuel energy into mechanical energy.They have no high voltage electrical ignition system, resulting in high reliability and easy adaptation to damp environments. The absence of coils, spark plug wires, etc., also eliminates a source of radio frequency emissions which can interfere with navigation and communication equipment.They generate less waste heat in cooling and exhaustThe carbon monoxide content of the exhaust is minimal compared to AVGAS enginesJet A fuel has better internal lubrication properties than AVGAS.
9Cessna J182T SMA Engine SMA SR305-230E-C1 oil and air cooled engine ECU Controlled with Manual BackupSingle lever power controlHartzell composite constant speed propApproved for Jet-A fuel onlyCessna will be offering the J-182T aircraft in It is powered by the SMA SR305 engine.This is an air cooled engine with internal oil cooling for the exhaust valve area in the cylinder.The engine is normally controlled by an electronic engine control (ECU), but has a mechanical backup throttle control of the fuel injection pump unit in the event of an ECU failure.The single power lever controls fuel scheduling for the control actuator with a mechanical override.The Hartzell composite constant speed prop is installed. The governor will have a control lever to ensure operation during preflight. It is not used for engine control.Jet-A is the only approved fuel for this aircraft
10SMA SR E-C1 Engine4-cylinder, horizontally opposed engine Direct drive engine, no gearbox or clutch Turbocharged and intercooled with no waste gate Air and oil cooled Single power lever and computer controlled fuel scheduling Fully mechanical, redundant backup fuel control system 100% power available to 10,000 ft standard atmosphere 75% power available at 20,000 ft standard atmosphere 2400 hr TBORecap the slide
11Oil Cooling Pressure Line Oil Cooling Galley for Exhaust Valve SMA SR E-C1 EngineP2/T2 SensorAir Cooling FinsIn this front view of the engine you can see the opposed cylinder design of the engine.On the right cylinder you can see the oil pressure line to cool the exhaust valve area in the cylinder. This oil galley is shown in the scrap view of the cylinder head’s cutaway.The P2/T2 (Pressure and Temp) sensor of inlet air is used by the ECU to schedule the correct amount of fuel for the air pressure/ density in the intake manifold..The prop governor for the Hartzell constant speed prop in installed between the alternator and the starter. There is a lever to opsck check the governor and prop on preflight. The governor maintains prop RPM during normal operation of the engine.The starter is designed for this engine to specifically overcome the high cylinder compression during the starting cycle.Oil Cooling Pressure LineProp GovernorOil Cooling Galley for Exhaust Valve
12Fuel Injector Return Lines SMA SR E-C1 EngineFuel Injector Return LinesFuel Injector LinesOn the left side of the engine you can see the vacuum pump and turbocharger.There is no waste gate used in this design since C.I. engines always run ‘lean’ and the cylinder cannot be over pressurized by the turbo output.You can see the fuel filter mounted to the engine mount truss.There are four fuel injection high pressure lines running from the fuel pump assy to each cylinder fuel injector. The red jacketed fuel return lines return unused fuel to the engine fuel system.Vacuum PumpTurbochargerFuel Filter
13SMA SR305-230E-C1 Engine Air Shut Off Valve Fuel Injection Pump ECU On the right side of the engine you can see the fuel injection pump.This is a Bosch “diesel” fuel system. There is a hand pump assy on the side of the fuel injector to bleed air out of the fuel system after a fuel system component is replaced.The air shut off valve in the inlet plenum is a way to ‘choke’ off the engine in the event of an emergency.The ECU (pictured under the engine) is installed in the cabin. The harness is routed through the firewall for all of the engine sensors.Fuel Injection PumpECU
14Back-up Power Lever Connection Fuel Injection PumpControl ActuatorIn this rear view of the engine you can see the dyna-focal engine mounts and truss structureThe fuel injection pump and the small black bleed hand pump with the HP fuel injection lines is seen.On the right side of the pump assy is the control actuator. This uses a servo motor to control fuel scheduling as commanded by the pilot’s power lever angle and a LVDT (Linear Variable Displacement Transmitter ) to give the ECU a feedback that the fuel rack is positioned by the servo for proper fuel flow to the throttle lever position.At the rear of the pump assy is the back-up power lever control. In case of ECU failure, the pilot moves a lever in the cockpit to engage a ‘throttle cable’ to the internal fuel control; rack to provide direct rack control with the power lever.You can also see various ECU sensors and harnesses in this view.Back-up Power Lever ConnectionECU Harness
15SMA ECU SystemThis slide shows the ECU system schematic of the engine.There are several engine mounted sensors that give the ECU data on engine RPM, T2/P2 (MP), fuel pressure, fuel temperature, start switch position for preheat, fuel rack position, throttle lever position and mechanical back up lever position
16SMA Fuel SystemThis shows the fuel system high pressure and low pressure fuel circuits.The mechanical pressure opening fuel injector can also be seen.Note the fuel returned from the injectors is routed back to the fuel injector inlet for ‘re-use’ by the fuel system.
17SMA Starting SystemThe engine starting system uses glow plugs to pre-heat the cylinders on cold mornings.This is controlled by the ECU through the pre-heating unit through glow plugs installed in each cylinder.The starter has been designed to overcome the high cylinder compression during starter use.
18J182T Engine IndicationThe engine indicators are shown on the EIS (Engine Indication System) display portion of the MFD.Engine annunciations and alerts from the ECU will be displayed on the PFD.You can see the engine power levers as well.There is a back-up MP indicator partially hidden by the pilot control wheel.
19SMA J182T Engine ControlsIn this view of the engine power controls you can see the THROTTLE lever as well as the MODE selector lever that engages the throttle directly through a cable control to the fuel injection pump control rack.There is a throttle cutoff lock button that must be depressed to bring the throttle lever to the cutoff position.To select the Manual backup mode, you must align the throttle lever with the small white triangle printed on the quadrant cover, then you lift the red MODE lever, move it aft and then press the knob in to lock the MODE knob in position as seen in the inset picture.You can now select the required power level with the throttle lever.With the MODE lever in the Mechanical Backup position, the ECU no longer controls the engine fuel scheduling
20SMA J182T Engine ControlsThere are other controls and indicators used with the J182T’s engineYou see the red knob for the emergency engine shutdown control. You pull this knob out and hold it until the engine stops.There is a standby manifold pressure indicator that can be used to set engine power if there is a failure of the G1000 EIS display. The turbocharger has no wastegate system. You cannot overboost this engine, there is no red line setting for manifold pressure.The engine preheat switch and the Governor Test Control knob are adjacent to the start switch. The governor test is only used during the BEFORE TAKEOFF POH or checklist procedures to cycle oil into the prop dome. The pilot does not have any direct input to throttle position except for the throttle lever.The start switch is not a mag switch, it simply engages the starter.The alternate air control allows bypass of the intake air filter should it become clogged.
21SMA Engine IndicationThis slide shows the location off the various engine sensors for the G1000 EIS display.It is important to note that the ECU system uses sensors for monitoring the engine that are not used for the cockpit EIS display.It should be noted that there is a backup manifold pressure gauge installed in the cockpit for use in event of an EIS failure.
22G1000 EIS Display Normal Mode Here is the Engine Indication System display for the J182T with the engine mode control selected in the normal mode.On the left we see the Engine Display mode:The engine output is measured in PERCENT of POWER as well as RPM with the MODE lever in NORMAL mode. The rest of the indications are horizontal bar indicatorsOn the right we see the System Display mode:This mode displays PERCENT of POWER as a round indicator, but the RPM and other parameters are displayed as numeric values, similar to the standard AVGAS NAV III acft. The Lean Display mode is not used for the J182T, but the CHT is now displayed in Bar Graph form in the System Display
23G1000 EIS Display Backup Mode Here is the Engine Indication System display for the J182T with the engine mode control selected in the Mechanical Backup mode.The big difference is that when in mechanical backup mode, the ECU can no longer compute a percent of power indication so the primary power indication is now a Manifold Pressure gauge at the top of the EIS display.All the other indications are the same as in Normal mode.There is an analog manifold pressure indicator installed next to the standby airspeed indicator under the G1000 screens.
24G1000 EIS SoftkeysThere are some new functions for the ENGINE softkeys for the J182T aircraftThe ENGINE SK will allow the operator to display the ‘normal’ ENGINE pageThe SYSTEM SK will allow the operator to view the engine SYSTEM pageThe CYL SLCT SK will allow toggling between cylinders for individual CHT temps to be displayed one-by-one. Normally the HOTTEST CHT is displayed in the ENGINE page.The ECU CLR allows the operator to clear select ECU faults, such as a ECU MAJOR fault that is induced by the operator when the MODE is placed in the MECHANICAL BACKUP position for maintenance or flight training. After you place the lever from the MECANICAL BACKUP detent back to the NORMAL position (with the engine shut down of course!) you can reset this fault using this SK.
25Fuel Cap ChangesHere we see the Fuel Cap and Fuel Placards as installed on the wing of the J-182 aircraft. Note the color of the cap and placards.
26Standard Jet-A Fuel Truck Nozzle Jet-A FuelingTo prevent mis-fueling on Jet-A powered aircraft with AVGAS, Cessna has developed a new fuel filler assy.Here we see the ‘spade’ shaped standard Jet-A fuel filler nozzle.Standard Jet-A Fuel Truck Nozzle
27Jet-A FuelingJet- A Spade Nozzle Does Not Allow Fueling with Round Avgas NozzleHere is a view of the fuel filler assy with the fuel cap removed.You will notice that the filler assy will not accept the round AVGAS fuel nozzle.There are spring loaded flapper doors that close off the filler when the Jet-A fuel nozzle is removed.Flapper Doors Prevents Fuel Siphoning if Cap is Left Off
28Jet-A FuelingJet-A Nozzle Inserted into Fuel Filler Assembly Note “Stop” for NozzleHere is the ‘inside’ view of the nozzle inserted in the fuel filler assy.You can see that the flapper doors are opened when the Jet-A nozzle is inserted.There is also a stop provided to avoid damage from inserting the nozzle too far into the fuel tank.Flapper Doors Opened by Jet-A Nozzle
29Standard Jet-A Fuel Truck Nozzle Jet-A FuelingStandard Jet-A Fuel Truck NozzleThis is the “Line Service” view of the Jet-A nozzle inserted into the filler assembly during refuel operations.This filler assembly will help reduce mis-fueling incidents during cross-country operations.
30J182T Performance DataHere is some information concerning the performance of the J182T compared to a Cessna 182TIf you look at the Spec and Dec numbers for the 182T, the standard empty weight is 1968 Lbs with a max useful load of 1142 Lbs. Using the preliminary Spec and Dec for the JT-A, standard empty weight is 2092 Lbs with a max useful load of 1018 Lbs. The JT-A is 124 Lbs heavier! But if you look at the performance numbers, you get a feel at how much more economical the SMA engine really is over the AVGAS burning Lycoming:The 182T has a Maximum Range and endurance of 930 nm.The JT-A has a Maximum Range and endurance of 1480 nm. The JT-A can go an additional 550 nm on the same fuel load! The 182T has a cruise range and endurance (80% max pwr at 7000 feet) of 773 nm and 5.4 hours.The JT-A has a cruise range and endurance (90% max pwr at 7000 feet) of 1007 nm and 6.7 hours.The JT-A can fly 234 miles further and stay aloft for 1.3 hours longer than a 182T! The 182T has a cruise range and endurance (55% pwr at 7000 feet) of 920 nm and 7.6 hours.The JT-A has a cruise range and endurance (50% pwr at 7000 feet) of 1385 nm and 12.7 hours.The JT-A can fly 465 miles further and stay aloft for 5.1 hours longer than a 182T!
31Compression Ignition (Diesel) Technology Cessna J182T SMA Engine ReviewCompression Ignition (Diesel) TechnologyCessna J182T SMA EngineJ182T Engine IndicationFuel Cap ChangesJ182T Performance DataQuestions, Answers and Wrap-UpIn review we have discussedBasics of Compression Engine TechnologyThe SMA C305 engine installed in the J182T aircraftThe J182T EIS pagesJet A fuel cap changes andJ182T Performance DataAre there any questions?