Installation of a CHT probe is amazing simple and, in this article, we show you how to do it yourself. You begin with installing the CHT probe in the rear spark plug of both the front and rear cylinder so the cylinder head probe is going to go in the aft plug with the plug closest to the rear of the airplane in both the front cylinder and the rear cylinder. Start with taking out the spark plug. With the spark plug out, we recommend application of a little bit of anti-seize compound on the threads. With the spark plug out you should notice the presence of a compression washer – make sure it stays there. There will also be a rubber grommet or gasket that will come out of the shroud on the engine – don’t forget to that back as it seals off the spark plug and prevents moisture and dust from entering. You might also have a drill a small hole on the engine shroud and pass the CHT probe wire through it otherwise fitting the sparkplug cap would be almost impossible (and might damage the probe wire). Seat the CHT probe on the spark plug and then bend the probe upwards so the wire will be facing upwards when you re-fix the sparkplug. Initially tighten the spark plug by hand and then by tool. Finally, gently push the rubber grommet / gasket into place. You might have to use a blunt tool like a screw driver to fix the gasket into place. Once you re-installed the spark plug and gasket in place, you will need to clamp the CHT probe wire in place so that it does not flap around in the wind or touch something hot which might result in wrong data being fed into your CHT display unit / EDM. Now, in the event you need to extend the CHT probe wire do the following: 1. Strip the ends of CHT probe wires and make small loops at the ends. 2. Repeat this process with the type-K extension wire (if they too have to be extended). 3. Prepare the splice barrels and heat shrink. 4. Pass the wire through the splice barrel and heat shrink tube. 5. Lay the CHT Probes and type-K extension loops over each other. 6. Slide the splice barrel over the parallel loops. 7. Crimp the splice barrel with a crimping tool (use a crimping tool with a grip for non-insulated terminals –the ones that have a cradle on one side and pierce a small hole on the other). 8. Slide the heat shrink over the splice and heat with a heat gun or lighter. 9. If you followed the above steps, you should now have a perfect thermocouple splice. More information at: https://www.jpinstruments.com/shop/cht-probe-4-pack/
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Looking for an engine data management system that offers precision diagnostics, superior features, monitors 29 different critical engine parameters? Look no further than the EDM 790 system. The EDM 790 manufactured by JPI, USA, is perhaps the best aftermarket EDM and is worth every penny you spend on it. Moreover, though under US ten thousand dollars, this 4 / 6-cylinder EDM includes the transducers in its price and kit. An EDM is not something you change every year or even every other year, therefore; when planning to upgrade, you as the owner of your aircraft, will naturally want the most advanced, safest and best EDM that money can buy. Doesn’t matter how you analyse it, the EDM 790 system is truly the most advanced twin piston engine-monitoring instrument in the market. The Engine Monitors has been certified for quality and is as good as having onboard a Flight Engineer and Maintenance Manager. Here’s why the EDM 790 is so good: Every 4 and 6-cylinder aircraft has twenty-nine critical components that ideally require constant monitoring. The EDM 790 does just that – it monitors each of these components (provided they are connected to the EDM), using state-of-the-art high precision sensors (also manufactured by JPI). Armed with the latest microprocessor technology and quick response high precision sensors, the EDM 790 will critically analyse incoming data and compare it with pre-fed high and how values. Any sensor data that is not within the pre-set limits gets flagged and pilot(s) alerted. In fact, each of these critical components is monitored 4 times a second! Moreover, the EDM 790 is paired with linearized thermocouple with accuracy of better than 0.1 percent or 2 F°. This feat in high precision has been tested and certified and certified by the FAA. EDM 790 – always alert From the moment the aircraft engines are fired up, to switch off, the EDM 790 remains constantly alert monitoring all 29 critical parts of the aircraft engine - four times every second. In fact, even if the pilots have changed the display page and are looking at something else, the engine monitoring does not stop – it continues in the background. Precision The EDM 790’s precision is a combination of its linearized thermocouples, fast response sensors and state-of-the-art microprocessor circuits. No competitor product comes even close the matching the precision of EDM’s manufactured by JPI. Easy to operate The EDM 790 has two buttons located on the front and these two buttons are all it takes to programme the EDM and to use all its functions. Even ‘Leaning’ is done automatically with the LeanFind™ procedure. With the EDM 790 onboard, the aircraft maintenance engineer or technician now has substantially more diagnostic information available that can be downloaded via the data port. For more information, please visit: https://www.jpinstruments.com/shop/edm-790/ The EDM 700 series engine data management system is one of the finest engine monitoring instruments available for the aircraft. In this article, will provide you with an overview and the special features of the engine data management 700 system. To begin with, the EDM 700 is analogues to a flight engineer always present in your cockpit and working silently in the background constantly watching over your engine while the pilots concentrate on flying the aircraft. Overview & Special Features of the EDM 700 System The EDM 700 Single Engine Monitor critical components of the aircraft engine three times a second and will warn the pilots instantly if any parameter is below or above the expected norm. The EDM 700 collects data and displays it for the pilots in a useful way. The EDM 700 is used to monitor engine temperatures and voltages, adjust the fuel air mixture and diagnose engine malfunctions. In the centre of the display screen, is the exhaust gas temperature (EGT bars) with the cylinder head numbers displayed on the top of each bar. The height of each column represents the EGT. The pilots can either see the display in ‘redline’ view or ‘normal’ view. The former is a percentage view of the EGT. In the normalized view the pilots can see even small subtle changes in the temperature – this enables the pilots to monitor the EGT very closely. In the normalized view, to begin with, all bars are equal height but; if there is any increase of decrease in temperature, the column height will instantly change. Each tick on the bar represents a 10-degree change. Actual EGT and CHT figures are displayed below the bar graph. This unit also displays the rate of shock cooling of the most rapidly cooling cylinder in degrees (ideal value should be below 50 degrees) per minute. Other displays include the bus voltage, the difference between the hottest and coolest exhaust gas temperatures. If you have the following optional features installed then, these too will be displayed: 1. The outside air temperature 2. Oil temperature 3. Fuel flow There are two buttons on the front panel. These control all functions of the EDM 700 on the left side is the step button and on the right side is a lean find button. Roughly 10 minutes after the EDM 700 is turned on it will automatically index through all parameters. Pressing this step button will turn this into a manual indexing mode and the pilot can observe each parameter value for as long the pilot wants. To resume automatic indexing, the pilots just needs to tap the lean find and then tap step to switch between the percentage view and the normalized view. More information at: https://www.jpinstruments.com/shop/edm-700/ EDM 700, Single Engine Monitor The only time we really look at or think about the ignition system is when the aircraft engine fails to respond at the turn of the key. Today, let’s examine this little device that could make or break your day in the sky.
The Engine Analyzer / System Monitor 350 is a nifty little power-packed device which, when connected to the sensors, reads and analysis engine data. It effectively is a secondary pair of ‘eyes and ears’ for your aircraft – one that keeps constant watch over the engine. Occupying just 3.25-square inches of space in the aircraft’s dashboard, the aircraft engine monitoring system 350 manufactured by J.P Instruments, USA, is very easily fitted. Packed with electronic chips, the aircraft engine monitoring system 350, analyses 24 different function of the aircraft engine. Starting at just $798 for the basic 4-cylinder EDM 350 kit, this is one device that represents enormous value for money. J.P. I also have the 6-cylinder EDM 350 version that retails at $998. If the probes are already in place, fitting the EDM 50 can be done in as little as 30 minutes. Simply create a 3.25-inch space in your aircraft dashboard, thread all the probes through the newly created empty space and attach them to the 350 unit. Next, ‘plug-in’ the EDM 350 Aircraft engine data manager into that 3.25-inch space, secure the screws and you’re done. Information is power - the working of the EDM 350: Think of the Engine Analyzer / System Monitor 350 as a little onboard computer. It has prefed upper, lower and normal parameters for 24 different parts of your 4 or 6-cylinder aircraft engine. When the aircraft engine is powered on, the 24 sensors begin feeding data into the EDM 350. As the data flows in, two things happen; one- the EDM 350 displays the information in a neat and intuitive manner. Depending on the pilot selection, the data may be displayed as actual numbers or as graphs. Secondly, the data is constantly compared with the pre-fed high and low values for each data stream. Any parameters that does not fall in the ‘normal’ range, is flagged and an audio-visual alarm is triggered. The high and low values can be manually entered by the pilot. The 24 engine parameters that the EDM 350 watches over are: 1. EGT - Exhaust gas temp. 2. CHT - Cylinder head temp - probes and harness included. 3. CLD - Shock cooling on all cylinders. 4. VDC - Voltage display. 5. Internal Memory - Enough memory to record 600 hours of data (recorded every 6 seconds). 6. USB Port - Convenient data port for quick and easy download of engine data. 7. ROP/LOP - Lean finder. 8. MAP - Engine Manifold pressure. 9. DIFF - Engine health. 10. EZTrends Software - Graphics software with Google Earth location included. 11. O.T. - Engine oil temp. 12. RPM - Prop rotation speed. 13. F.P. - Fuel pressure. 14. OAT - Outside air temp. 15. O.P. - Engine oil pressure. 16. CRB - Carburettor temp. 17. CDT - Compressor discharge temp. 18. TIT - Turbine inlet temp. 19. L-R-Main - Fuel quantity in all tanks. 20. V-2 - Second volts readout. 21. AMP - Battery load output in amps. 22. % HP - With FF, OAT and RPM Sensor. 23. Amp-2 - Second load readout in Amps. 24. FF - Fuel flow includes: • GPH - Gallons per hour. • H:M - Endurance in hours and minutes. • REQ - Fuel required to way point / destination. • MPG - Miles per gallon • USD - Fuel used. For more information on EDM 350 Aircraft engine data manager by J.P. Instruments, please visit: https://www.jpinstruments.com/shop/edm-350/ The aircraft engine data manager is something you select carefully and install - usually just once in your life-time. For this reason, J.P Instruments have made sure that their engine data managers for experimental aircraft are absolutely the best that money can buy and this goes for the EDM 740 too.
Current aircraft flying around in the skies have either the analog fuel flow instrument (aircraft 10+ years old), or have the new digital version. While the analog ones simply display the balance fuel quantity, the digital version (depending on the model), provide a whole host of important information. Aircraft owners who have opted for after-market fuel flow instruments, usually install the fuel scan 450 Twin manufactured by J.P. Instruments, and is probably the best fuel indicator in the market. Typically, modern-day fuel flow instruments (depending on brand and model), offer lots of information in real time including: 1. Fuel quantity alarm. 2. Pilot selectable quantity display in gallons, litres or pounds. 3. Interface with GPS (depending on the brand and model). 4. Automated K-factor calculation. 5. Real-time fuel flow rate. 6. Solid-state pulse generating rotor fuel flow transducer. 7. Total fuel consumed and fuel balance. 8. TTE - Time to empty at the current fuel consumption rate. 9. Fuel Management. After a refuel, the pilot manually enters the quantum of fuel filled into the tanks. From there on, the digital fuel flow instrument takes over. It goes without saying, that the accuracy of fuel balance and time to empty will depend on the accuracy of the figure entered by the pilot. Typical problems include fuel figure entered in gallons while fuel flow instrument is set to litres or visa-versa. If the fuel flow instrument is paired with a GPS then the fuel-to-next-way-point figure will also depend on the initial fuel input figure. Modern digital Fuel Flow Instruments use a small and highly compact turbine transducer that is fitted into the fuel outlet pipe itself and measures the fuel flowing into the engine. The fuel transducer works in an identical way to the spinning water wheel. This ingenious design paired with modern day electronics ensures that the transducer keeps performing and accurately displays fuel figures. In terms of accuracy, fuel transducer does to the fuel indicator what modern electronics did to the heart-rate monitor i.e. the high rate of pulses generated by the transducer, ensures higher accuracy in calculating fuel flow. The functionality of the aircraft fuel scan 450 Twin manufactured by J.P. Instruments includes: Operating Modes: There are two operating modes – Manual and Automatic Indexing. Programmable Alarms: Pilot can programme minimum fuel alarm. This alarm will activate when the level of fuel left in the tanks is equal to the figure entered by the pilot. Sleep Alarm: Once low fuel alarm is sounded and the pilots are aware of the situation, he/one of the pilots simply presses the STEP button and the alarm will ‘sleep’ for 10 minutes or, press and hold a couple of seconds and the alarm will turn off. Automatic Self-Diagnostic: At start-up, the fuel flow instrument will run a self-diagnostic to make sure the electronics is working well. These and several other functions and features, make the aircraft Fuel Scan 450 Twin manufactured by J.P. Instruments an awesome product. It is hardly surprising therefore, that it has been declared as the best aviation consumer product for this year. More information here: https://www.jpinstruments.com/shop/fuel-scan-450-copy/ The installation and maintenance of the EDM 960 Twin Engine Management System must only be carried out by certified aircraft maintenance engineer. The EDM-960 Display Installation Before you install the EDM 960, located your fuel quantity calibration records as the installation engineer might need to refer to it at time of installation of the EDM 960. Also, before you install the EDM 960, it might be a good idea to spend a few minutes in the cockpit and decide on exact location of the EDM 960 display. The best recommendation is to install the display within the natural scan and easy reach of the pilot. When you have figured out the exact location where you want the EDM 960 placed, insert the special key card that came with the unit. Each unit is paired with a specific key card that has been pre-fed with data specific to your aircraft make and type. EDM-960 Key Card Installation Once the key card is inserted into the special slot in the unit, leave it in place and do not remove the card. When the aircraft engine is switched on, the Remote Auxiliary Display (RAD) of your EDM unit, will display the aircraft make and model in the right engine RAD. The Left side will simply display “EDM-960”. To install the key card, open the small access flap located on the side of the EDM-960 display. Hold the Key Card so that the UP arrow is facing up and insertion arrow is facing to the right. Now insert the Key Card in the guide rails until you feel it snap into place. Close the access flap. Power up the EDM and confirm that your aircraft make and model is displayed in the RAD. Install the EDM back into the aircraft. Power Connection: The EDM-960 accommodates 14V or 28-volt electrical system. When installing the EDM 960, care must be taken to ensure that the master bus power must be individually provided via three, 5-Amp circuit breakers, to the two DAU units and the EDM-960 head. The DAU ground wires should be connected to the engine block. The EDM 960 Twin is comes with Teflon insulated wiring harness configured for the correct number of cylinders for your aircraft. Each wire harness is marked C1= CHT-1, E1= EGT-1 and so forth. Post-Installation Trouble Shooting / maintenance: 1. On start-up, a missing column of figures in the display would indicate that the continuity check diagnostic routine has found an open line or probe with no connection. An error message will indicate which cylinder to look at. 2. A missing column of figures during flight indicates a reading that is jumping around or incorrect. Solution: Remove the probe from the line up to prevent false alarms. 3. A negative reading (-) in front of the number indicates reverse polarity on the red/yellow wire to probe. 4. Erroneous or erratic readings on one cylinder reading. Solution: Swap the suspected probe with a probe from a good cylinder. If the problem is transferred to the good cylinder then the probe is faulty and should be replaced. If the problem remains the same, it is in the Thermocouple hook-up wiring from the TIT Probe to the instrument or it can be in the ring terminals crimped to the wire. 5. If the temperature reading is changing more than 500°F in one second a loose wire crimp or probe could be the problem. A malfunctioning probe will automatically be removed from the scan. For more information, please visit: https://www.jpinstruments.com/shop/edm-960/ Even small quantities of dust and dirt entering data ports of various aircraft instruments are often sufficient to throw a fit at the most inopportune time. When receiving a newly purchased aircraft instrument, have it thoroughly examined and as far as possible, fully tested before installation and take off. The installation process itself should be handled with care. Tighten the nuts (or screws) too much and you could end up destroying the outer casing which in turn could severely damage the internal parts. Aircraft instrument repairs are supposed to be handled by approved shop and done under controlled conditions. Every repair shop says so in the brochure. But the reality is usually something else. While these shops are run by properly licensed mechanics and engineers, they in turn, hire assistants who have little or no experience handling delicate aircraft instruments. Often times, damage can occur during a maintenance schedule itself. Surprised? Consider this; an inattentive mechanic’s assistant who drops an instrument just 6 inches, will subject its internal components to almost 2 G’s of force! This is enough to damage a lot of sensitive instruments especially Gyros. Similarly, careless assistants can result in contaminates or even tiny nuts and screws getting into the internal mechanism of an Aircraft Digital Instruments – imagine what that could do when the plane is being tossed around during a turbulence. It’s a headache you don’t want. Tips to maintaining aircraft instruments: 1. Do not lubricate fittings on vacuum gyros as it could result in over- tightening of screws and damage the fitting and the back-plate ports. 2. Cover / tape all ports when shipping to reduce possibility of dirt or dust entering the ports. 3. Gyros should always be allowed to run-down before removing. This is done to prevent damage to the gimbals and ultra-sensitive bearings. Similarly if you need to keep a gyro in storage for more than a month or two, it needs to be "powered-up" and operated for no less than 39 minutes so as to allow the bearings to be adequately lubricated. 4. If you need to check the accuracy of the Manifold Pressure Indicator, you should ideally compare it with the Altimeter's baro setting. Also remember, that some altimeters have vibrators in them. These vibrators are installed to reduce friction within in the instrument and thereby enhance accuracy. During maintenance, the mechanic needs to ensure that the vibrator is functioning properly. 5. Whenever the True Airspeed Indicator is taken out for maintenance, the mechanic needs to make sure the capillary tube is intact otherwise; the true airspeed indicator will have to be replaced. 6. It is very important that any instrument like Aircraft Engine Monitor should be properly tagged before handing over for repairs. 7. Always make sure the connectors on your fuel probes or Oil Temp Probes are clean and shiny. For more information on Aircraft Instruments, please visit: https://www.jpinstruments.com/ |
AuthorJ.P.Instruments was founded in 1986 in Huntington Beach, California, USA. Its founder, Joseph Polizzotto, is now the current CEO. Archives
May 2019
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