The aircraft engine performance can be analysed in detail provided there is some way for the engine data to be stored and later retrieved.

Start with ensuring that the RPM sensor is fitted to the correct vent plug of the slick magneto.

CHT Bayonet probes come in two flavours; non-grounded and grounded.

Due to consistency of their reaction to heat, these types of probes are ideal for use in aircraft and other machines where precision is a must.

This article helps you compare the two EDM’s and select the one that fits your requirements and your budget. Both these aircraft engine data monitoring systems are manufactured by J.P. Instruments.

The new features that have been added to the EDM 830 include lean of peak default so whenever the pilot uses the lean fine mode, he can choose between rich of peak or lean of peak as his default start-up setting.

The EDM 900 has a long list of function - only a handful are covered here.

For accurate temperature data, ensure that the tip of the probe is in the centre of the exhaust stream. When sure that the probe is in the right place, tighten the stainless-steel clamp to a torque of 45 in/Lbs.

Spring loaded bayonet mounted CHT probes are usually K-type probes. These twist and lock into a screw-in adapter and screw into the cylinder head thermo well. The probe is spring-loaded and helps ensure contact with metal instead of air.

Each of these Aircraft Sensor System is mounted in the fuel line prior to the fuel distributor or carburettor and, they measure the actual fuel flowing through.

In a turbocharged aircraft, the MAP does not vary with the altitude because the presence of the compressor means the aircraft engine does not have to rely on free-flowing air.

The EDM 950 monitors the aircraft engine parameters roughly 180 times a minute and will warn the pilot the moment any parameter exceeds the pre-programmed limit.

It is easily installed (vertical or upside down or horizontal) and is considered to be amongst the most advanced and accurate piston engine-monitoring instrument.

ICA is not required. The internals are ‘card-based tech’ so, if any part malfunctions, all that the maintenance crew needs to do, is to remove and replace the JPI supplied new or repaired components and the aircraft is good to go.

The best location therefore, is to place OAT probe under the aircraft wing but sufficiently outboard so as to avoid exhaust heat - the bottom of the fuselage would be an ideal location.

They constantly monitor the health of the aircraft engine and any red-line events are instantly brought to the pilot’s attention via audio-visual alarms.

If the aircraft uses a carburetted engine, place the fuel flow transducer before the carburettor.

Each slim line gauge has a red line LED so any reading that is over or under is instantly brought to my notice.

Kit will depend on 4 / 6-cylinder version and options selected.

The dimming switch is placed at the top right side of the scanner.

The presence of the compressor means the aircraft engine does not have to rely on free-flowing air that gets less and less with altitude.

Using sophisticated analytical software, the technician can analyse the Precision Engine Monitoring performance minutely and figure out if any part of the engine required tuning / repairs or replacement.

Push wires from the cabin through the firewall to the engine side and try to use existing rubber grommets. When you've finished, use flame retardant silicone to fill up any gaps along the wire route.

K-type CHT probes have sensitivity over a wide temperature range and are the preferred type for use as EGT or TIT probes.

Seat the CRB Probes on the spark plug and then bend the probe upwards so the wire will be facing upwards when you re-fix the sparkplug.

Every 4 and 6-cylinder aircraft has twenty-nine critical components that ideally require constant monitoring.

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.

The propellers are connected to the crankshaft which in turn rotates a rotor inside the magneto.

The Engine Analyzer / System Monitor 350 is a nifty little power-packed device which, when connected to the sensors, reads and analysis engine data.

This highly innovative and aggressively priced product is aimed at 4- and 6-cylinder experimental aircraft.

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.

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.

Aircraft instrument repairs are supposed to be handled by approved shop and done under controlled conditions.

The EDM 790 is designed to watch over 29 critical parameters of the aircraft engine and to sample the data 4 times a second. Nothing even comes close to being as good.

Smaller than the average cell phone, the EDM 350 requires just 3.25 square inches of space amongst your instrument panels.

The EDM 900 comes equipped with the Remote Annunciator Light ‘RAL’ that provides notification that an alarm is present.

The J.P. Instrument manufactured Classic Scanner is a small convenient package with an even more convenient price tag.

The EDM 760 connects to the aircraft engine via multiple sensors. These sensors pickup up the engine data and transmit it via wires to the EDM unit.

The EDM 790’s linearized thermocouple accuracy is simply the best in the market - there is nothing in the aviation market that compares to J.P.I EDM 790’s linearized accuracy.

The aircraft on which the EDM 740 is to be installed, should have necessary FAA approvals.

On ground, the pilot needs to eyeball the IAT probe to ensure it is not coated with sooth, oil or bird feathers as these could cause the IAT probe to malfunction.

To further improve the functionality of the aircraft engine monitors, manufacturers such as J.P. Instruments amongst others, have gone a step ahead and inserted memory cards within the engine monitors.

The Aircraft Engine Data Management 730 is one of the easiest to programme and all programming is done from the front panel.

Provide service loops at the instrument – you don’t want to run out of wire during maintenance at some future date.

The aircraft Engine Data Manager 350 (EDM 350), by J.P. Instruments is a small box-like device with an LCD screen on the front and it keeps track of the vital functions of the aircraft engine.

The CHT Bayonet probes are the threaded probes and are commonly known as ‘CHT Bayonet Probes’. These are typically used on Lycoming engines in aircraft.

The EDM 800 converts your RPM manifold pressure outside air temperature and fuel flow into horsepower. To achieve this a small one-time calibration is required.

I remember that in comic books as well as WWII films pilots would know something was wrong just by listening to the difference in engine sound.

Compression always leads to heat. So, when air is compressed in an aircraft engine, heat is generated. Also, the mass flow rate of air through the engine will have an effect on engine temperature and engine performance.

Well, “slim-line” means it occupies very little physical space so everything of importance can be placed right in front of the pilot instead of being spread all over the cockpit.