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Aircraft Instruments

4 days ago

The Functions of an Aircraft Sensor System

RPM SensorModern aircraft sensors play a critical role in the flight economy and safety of the aircraft, its passengers and the cargo it carries. There are several types of sensors used in modern aircraft.

Temperature Sensors – As the name suggests, these are sensors used to measure the temperature of various engine components within the aircraft. Temperature sensors are usually used to record Cylinder Head Temperature (CHT), Exhaust Gas Temperature (EGT), Engine Oil Temperature (EOT), Fuel Temperature (FT), Hydraulic Fluid Temperature (HFT) etc.

These sensors usually work on the Resistance Temperature Detector (RTD) principle which essentially means that change in resistance (ohms) in a metal amalgam is directly proportional to temperature changes applied to it. So when an electrical current is passes through it, the change in resistance is calibrated and displayed as temperature of that particular component at the point where the sensor is placed.

Liquid Level Sensors – A liquid level sensor is generally mounted in thermowells and directly installed into reservoirs, tanks, sumps and gearboxes in the aircraft. These sensors are generally available as single point or multiple point interface elements or liquid levels and connected to onboard display units in the cockpit.

Flow Sensors – As the name suggests, a flow sensor is used to monitor the flow rate or any liquid be it aviation fuel or oil. The flow sensor is mounted within a thermowell and it might also contain an electronics unit that connects to a Fuel Gauges. The flow sensor is usually directly installed into pipe that carries the liquid for which the flow rate is being measured.

Pressure Sensors – A pressure sensor is used to measure pressure that is above or below a pre-set figure at the sensing location. The pressure sensor is directly installed into ducts, pipes, tanks, sumps, reservoirs or gearboxes in the aircraft. It can be specified to indicate either absolute or differential pressure.

Proximity Sensors – Proximity sensors are usually used to confirm the status of something that opens or closes e.g. doors, landing gear door, cargo bay door and so forth. It is also used to confirm if the landing gear is extended or retracted.

RPM Sensor – The aircraft spark plugs are powered by a mini power generator in the form of a Bendix Magneto generator. The Bendix Magneto is essentially a small generator with a transformer, breaker switch and a distributor to guide the high voltage to the spark plugs. It is important that this magnet rotate within the prescribed range and to confirm this, you need the Slim Line Instruments which is a small cylindrical device that plugs into the magneto and provides a feedback to the RMP display unit in the cockpit.

Together, all these sensors provide critical information to the pilots and the pilots can either concentrate on flying when every reading is in the green or, take corrective action as required if one or more sensor provides abnormal feedback. The sensors therefore, have a direct bearing on the safety of the aircraft.

2 weeks ago

Save Money With JPI's Aircraft Fuel Flow Indicator

EDM 960 TwinAs of today aviation fuel costs are down but that in itself is no reason to fly Rich of Peak (RoP) unless you really need to. Flying Lean of Peak (LoP) not only saves money on your fuel bill, it also keeps your engine cleaner which means you would be saving on maintenance costs as well.

But to know whether or not you are saving anything, you need modern sensors connected to modern digital gauges installed in your cockpit. These modern digital gauges should include a Exhaust Gas Temperature (EGT) gauge, a Cylinder Head Temperature (CHT) gauge and a highly accurate Fuel flow indicator like the digital fuel flow indicator manufactured by JP Instruments.

When you run the aircraft engine using the RoP technique, there is an excess of fuel in the cylinder. While this may help keep the engines cooler, the exhaust ends up contaminating the oil and creating a hell of an overall mess including quicker carbonisation. There simply is no reason to be running the aircraft in the RoP technique. Also, cylinder pressure is much higher (between 80 to 100 psi) in RoP than in LoP.

Let us understand how you save money with LoP. When you operate the cylinder in LoP, it results in a longer, gentler, slower push on the piston because the peak cylinder pressure develops later from piston top dead centre than if the cylinder were to be operating in RoP. This means the EGT Gauge pressure only develops when the piston has travelled further along its downward stroke. So instead of a hammer blow (as in the case of RoP), there is now a gentle push because the piston inside the cylinder has already travelled far into the downward stroke of the cycle.

Higher cylinder pressure equates to higher CHT's. So in reality, operating RoP will result in higher internal cylinder pressures which in turn results in higher CHTs. whereas operating LoP at exactly the same Horse Power as the cylinder operating RoP will result in roughly 35°F lower CHT's. So your aircraft engine can actually run LoP at a lower CHT while producing the same horse power i.e. better speed, lesser fuel flow (as confirmed by the digital Digital EGT Gauge), lower Cylinder Head Temperatures – isn't that what every pilot wants?

Besides, when the aircraft engine is running in LoP, all fuel in the cylinder is used so there is nothing to blow back and contaminate the oil. Lower CHT and cylinder pressure also means lesser carbon deposits settling on the internal engine components as well so you save on the maintenance bill too.

A common misconception amongst most pilots is that you only operate LoP at low power settings. In reality, you can operate at up to 75% power without using a lot more fuel and this will be proved by your digital fuel flow indicator.

3 weeks ago

JPI's Accurate Electronic Data Management Systems For The Aircraft

Electronic Data Management SystemsHere goes the riddle for them into avionics: What goes 24 different ways and reads 4 times a second? Hints: 24 is the number of engine parameters; 4 is data re-check.

JPI's Accurate Electronic Data Management Systems for the Aircrafts or EDM are bar-graph Aircraft Flight Instruments that have met the harsh environmental standards of FAA, TSO. The JPI's Accurate Electronic Data Management Systems for the Aircrafts run a 3-year warranty and is a bright example of what latest microprocessor technology can do to the EDM! Besides, it frees you from the burden of field adjustments and calibration and also of ICA.

A credible and accurate Engine Data Management system must offer an accurate piston-engine monitoring using advanced technology, methods and materials and so far, the Engine Data Management 800 system has been considered the best in the market. It has been designed to monitor twenty-four critical parameters while the engine runs and the data upgrades four times a second. The riddle is solved.

The EDM 800, JPI's Accurate Electronic Data Management Systems for the Aircrafts, if simplified, is a personal flight engineer who’s always there as a background support, always on the watch over the engine while you concentrate fully on flying. The EDM 800 has some extra features (fuel-flow, for example) than the previous EDM 700. The fuel-flow control helps in automatic leaning. It’s a quick process run by LeanFind™. The RPM, Manifold pressure with EGT Gauge and Outside Air Temp with probe are also present. These probes respond to every temperature change due to their fine tip and space age metal construction. The EDM 800 thus becomes a primary replacement for CHT, OIL temperature and Turbine Inlet Temperature. The EDM 800 displays temperature digitally and in an analogue format for cylinders and also for the turbo-charger. For the latter, you’ll need to install a TIT probe adjacent to the TC.

A substantial amount of diagnostic information available in a timely, usable manner is a lot of help to avoid unnecessary worries while in the air. You may keep logs of all functions for 25 hours (@4 upgrades/sec) or 550 hours (@ 1 upgrade every minute). The total range spans from 2 to 255 seconds. This will include fuel used and you can download the data to any computer with an optional USB port.

How do you know it’s not just for show? Because it doesn’t stop at the GPH and leaves you hanging for a second instrument to read the rest! It accurately calculates OAT, RPM, MAP and Fuel Flow, which is most effective for a LOP-Complete fuel flow system. It is true data recording that works both under ROP and LOP Mode. True LOP is where you can see each cylinder going lean.

4 weeks ago

Revolutions-Per-Minute (RPM) Sensor Has Important Role In Aircraft

Revolutions-Per-Minute SensorInstruments inside an airplane’s cockpit are your medium to communicate with the airplane’s engine and keep a check on its overall health and performance during the flight. The RPM sensor thus makes for a vital component in your instrument panel, keeping you aware if you are within the operating limits as you are gunning the engine.

An overview:
The RPM or revolutions-per-minute sensor provides you with engine data and also logs them, creating a trend that comes helpful for preventive maintenance schedules and repair jobs. It helps the engine keep running for years to come.

The RPM sensor shows the readings through the RPM gauge, which can either be a standalone instrument or stays integrated in a single unit along with pressure, temperature, fuel level and flow gauges. For multi-engine aircrafts, there can be different RPM gauges with single, dedicated sensors or just one that keeps check on all the engines through multiple gauges.

Accurate engine monitoring during the course of the flight is important for it helps you to keep the engine revolutions within permissible limits and therefore, minimising the strains. All that culminates to a safe flight and if something doesn’t seem to be all right, the log of engine parameters helps you to set the glitches right afterwards.

Old vs. new
Mechanical, cable-driven tachometers are more common in older aircrafts and work with aid from a couple of flyweights attached to the pointer while the later types have the cable attached to a magnet rotating inside an aluminium cup. These are the Bendix/Slick Magnetos, which are more popular than the Dual Magneto type and are far easier to overhaul and therefore; are extremely cost-effective.

The Magneto supplies the power to the spark plugs and acts as a mini power-generator, There are a transformer, a breaker switch and a distributor built into it, the last one guiding high voltages to the spark plugs. The magnet must rotate within the prescribed range, which the aircraft RPM Sensor keeps track of. The sensor is a small cylindrical device plugged into this magnet.

Why EGT Gauges are big deals
Sudden RPM drops signify serious spark plug malfunctions. Or, it could indicate an inadequate lubrication of cams, leading to accelerated wear and therefore, late sparks that reduce sustainable RPM, resulting in lots of unburned fuel and energy kick-backs. If fuel is burned inside the exhaust system, it results in an abnormally high EGT.Only an accurate RPM sensor is an answer to this problem.

Replace your Fuel Gauges in an easy way
In case you need to replace your existing RPM sensor, just remove the vent plug from the magneto-port containing the rotating magnet. There are different sensors available for the Dual and Slick types; just insert the new sensor into the vent port and tighten before routing the wiring bundle back with sufficient slack. Plug in the connector to the corresponding colour wires in the instrument harness and you’re done!

1 month ago

The Advantages of Aircraft Engine Data Management System

Aircraft Engine Data Management SystemThis would be like wanting to know the advantages of Science or modern technology because frankly, without the aircraft engine data management systems in place, the pilots would have to sit staring at the dozens of analog dials and gauges in front of them. They would have to keep checking each and every one of them and occasionally pray that the dials are displaying the correct information.

The aircraft engine data management system consists of two parts – a display unit placed upfront in the cockpit and, several sensors strategically placed through out the aircraft engine and body (depending on kind of data being monitored).

To get a handle on the advantages of an aircraft engine data management system, let's do an example – let check what would happen with and without (say) a digital fuel gauge which is part of the aircraft engine data management system (EDMS).

Old Style Analog Fuel Gauge
Needle keeps bouncing and shaking – at best it provides a rough indicator of how much fuel is left in the tanks.

The only way you know how much fuel was used per hour of your current flight, was to look at the clock, figure time lapsed since flight began, deduct the current fuel balance from the fuel quantity at start of the flight and divide this figure by the hours lapsed. What you arrive at is at best, a guess-estimate.

If you are flying in a storm there is absolutely no accurate way to figure out your current fuel consumption. At best you can assume it will cost you a certain percentage more – anything from 25% to 50% increase in fuel consumption.

Knowing your current position especially when flying in the storm and using old analog gauges would be even more trickier. But you have to somehow figure out your current position and work out time to your destination. Once you have that estimate and having calculated your fuel consumption, you can at best guess whether you have enough fuel left to reach your destination.

Modern Fuel Gauge – part of the EDMS
Pilot fuels up the aircraft and punches in the quantity of fuel in the tanks.

From here on, the modern Aircraft Flight Instruments begins to monitor fuel consumption and provides a digital readout of the quantum of fuel used. The pilot can select between Gallons/Litters or Pounds.

Based on quantum of fuel currently in the tanks and quantum of fuel being consumed, the modern fuel gauge can provide information as to how much longer the aircraft can keep flying. This information is provided in real-time. So even if the aircraft is (say) flying in a storm and consuming additional fuel, the actual fuel being consumed is factored into all computation. This provides the pilots with a highly accurate picture.

If a GPS unit is connected to the EDMS, the on board computer in the EDMS will even calculate the quantum of fuel required to reach the next waypoint or destination and can even provide information on whether there will be any fuel to spare after arriving at the destination.

From the above example, we see that without a modern Slimline Instruments, the pilots would have to carry a notebook, pen, calculator, a stop watch and probably; a pocketful of prayers which is probably how the phrase “flying by the seat of your pants” originated. For technical information on aircraft EDMS please visit:

2 months ago

Aircraft Fuel Gauges - How They Work

Aircraft Fuel GaugesEssentially there are three types of aircraft fuel gauges – mechanical, electrical and digital (latest). Let's take a look on how each of these work.

The mechanical fuel gauge – how it works:
The mechanical fuel gauge used in aircraft uses a cork (currently the float is made from Nitrile rubber) that floats on top of the fuel. So when the fuel level goes up or down so does the cork. The cork in turn is attached at the end of a light-weight pipe usually made from tempered aluminium. As the cork (or rubber float) moves up or down so does the pipe. The pipe in turn is attached to a delicate gear system usually made from stainless steel. Through use of the gear mechanism, the up-down movement of the rod is converted into circular movement which is passed to a rod (or cable) that is attached to the fuel gauge via a drive magnet. So finally, the up-down movement of the float in the fuel tank, is converted into Full – Empty on the fuel gauge. While the mechanical fuel gauge for aircraft might still be used in old aircraft, it is more prevalent in older model cars.

As you can see from description of how the mechanical fuel gauge works, there are too many moving parts and one or the other might get jammed or disconnected due to intense aircraft vibration.

The electrical fuel gauge for aircraft – how it works:
The electrical fuel gauge for aircraft (also known as capacitance meter), does away with the moving parts altogether. Instead, it relies on a capacitor (hence the name) and an electrical amplifier besides of course, a fuel gauge.

Basically, a capacitor stores an electric charge the size of which varies with the dielectric (in this case the dielectric is either the fuel when it is full or air in the tank when it is empty). In very simple terms, as the air-to-fuel ratio changes, so does the capacitance. The capacitance charge is read by the fuel gauge in the cockpit and appropriate fuel information displayed.

Avionic Instruments for aircraft – how it works:
When any liquid including aviation fuel flows through a pipe, the flow rate can be measured to a high degree of accuracy (even after accounting for changes in density). Typically, once the aircraft is fuelled up, the pilot enters the total quantity of fuel per tank into the digital fuel gauge via the touch-screen keypad.

As the fuel flows through the fuel outlet pipes, the onboard computer keeps track of the fuel flow and deducts this from the respective total for that tank. The onboard computer located within the aircraft electronic management system (EDMS), digitally displays the balance quantity of fuel either in digital figures (depending on the EDMS mode) or, as bar graphs – one for each fuel tank. Because its a computer, the EDMS if coupled with a GPS, can also calculate whether or not the plane has enough fuel to reach its destination. This calculation is based on current fuel consumption and quantum of fuel currently in the fuel tanks. Since everything happens in real time, the information being presented to the pilots is highly accurate. Additionally, the onboard computer can trigger a audio-visual alarm if the fuel level drops below a certain level.

Very high tech Aircraft Engine Sensors (either stand-alone types or EDMS types), also have a backup fuel level sensors within each fuel tank. This information too is fed to the onboard computer which in turn determines if there is any variation between the calculated fuel balance and physical fuel balance. Any variation beyond permitted error margin would indicate a fuel leak and trigger an alarm.

2 months ago

Aircraft Electronic Data Management and Control Systems

Electronic Data ManagementAircraft Electronic Data Management & Control Systems (EDM's) ensure that the engines of an aircraft that contains an EDM operates with utmost efficiency, while remaining within safe operating limits.

Aircraft Electronic Data Management & Control Systems provide vital information to the pilots via electronic display gauges for assessing the engine’s condition. The EDM's not only help avoid disruption, they also enable the aircraft to fly with maximum fuel economy.

A typical Aircraft Electronic Data Management & Control Systems especially the ones manufactured by California based J.P. Instruments; is a high-integrity, full authority digital display and control that combines aircraft engine sensor information with operational parameters set by the pilot(s) to ensure that an engine performs at a safe and optimal level.

The Aircraft Electronic Data Management & Control Systems is hooked up to sensor probes usually via wires. These probes are mounted in various positions on and around the aircraft engine. Some probes are even mounted outside the aircraft to read external temperature and wind speed. A typical EDM is meant to continue functioning regardless of aircraft vibration, temperatures, pressures and humidity. It is built to be able to withstand electromagnetic fields and lightning strikes.

New generation Aircraft Electronic Data Management & Control Systems manufactured by J.P. Instruments provide a simpler solution for harsh environment aircraft engine control and high-integrity health monitoring. Compared to other Aircraft Fuel Fow Monitors and EDM manufacturers, EDM's manufactured by J.P. Instruments offer half the cost per function, thereby significantly reducing new product introduction lead times, and lowering through-life costs.

J.P. Instruments has been manufacturing Aircraft gauges for civil aviation use since 1986! Founded by Joseph Polizzotto who worked earlier as test engineer, J.P. Instruments has been pioneering after-market aircraft digital gauges for single and twin engined aircraft.

Main features of EDM's manufactured by J.P. Instruments:

FEWER “SURPRISES” - J.P. Instruments Aircraft Electronic Data Management & Control Systems help detect and prevent exceptional events that can occur during a flight. This means fewer unwanted engine-related “surprises”, as well as increased safety, availability, compliance and operational economy.

WORKSHOP WORK SCOPE OPTIMIZATION - J.P. Instruments EDM's help aircraft owners to optimise their workshop work scope by focusing on and only fixing the items that need fixing. This helps to reduce aircraft downtime, make the best use of resources and, maximise component life.

INTEGRATION WITH OTHER SYSTEMS – EDM's manufactured by J.P. Instruments can integrate well with (for example), Single Engine Data Analyzer. This in turn provides more holistic information including fuel-to-waypoint and fuel-to-destination.

EXCELLENT RETURN ON INVESTMENT – Installing J.P. Instrument Aircraft Electronic Data Management & Control Systems makes business sense because it enables the aircraft owners to immediately examine only key issues faced by the aircraft. No more digging around aimlessly to find the fault. A quicker maintenance turnaround means money saved, and a smaller maintenance bill. This return on investment continuously improves with time making this the best possible investment in safety and operability of the aircraft.

2 months ago

Specification and Features Of EGT Gauge System

EGT Gauge SystemOne of the finest EGT Gauge Systems for aircraft is manufactured by California based J.P. Instruments and branded as the 'Classic Scanner' – an EGT gauge that is perfect for any plane and especially for those pilots with a smaller budget.

The Classic Scanner EGT Gauge features a large red LED display readout of the temperature as it scans through each cylinder of your plane’s engine. EGT and CHT are both available and alarms are a standard feature. The pilot can select to monitor the temperature in degrees Centigrade or Fahrenheit. Coupled with J.P.I’s famous super accurate fast response probes, the Classic Scanner® (EGT Gauge System) also can let you know about shock cooling before its too late! The Classic Scanner® is FAA TSO approved and comes with a one year limited warranty.

The Classic Scanner EGT Gauge monitors every probe three times a second and can monitor up to 16 probes. This indexing rate can be adjusted from one every 1.5 seconds to 1 every 9 seconds. The EGT Gauge accurately converts the thermocouple’s millivolt signal to a temperature on the display. The thermocouple’s millivolt signal is amplified by precision instrument amplifiers which permit the use of fast, grounded type K probes.

A small “c” displayed in the first digit e.g. c370 indicates the unit is scanning Cylinder Head Temperature. A decimal point in the second digit e.g. I.450 indicates temperatures above 1000 F. A display of (say) I.990 indicates that the temperature exceeds the normal range of 1999 F. The voltage option will display voltage when the STEP button is held. Voltage readings are in tenths of a volt.

Alarm is indicated by a flashing CYL digit for the cylinder that is out of range. In the automatic mode the scan sequence will stop on the out of range cylinder and flash the CYL digit.

1. The Classic Scanner Aircraft Flow Sensors System features a large red difficult-to-miss LED display that makes flawlessly easy.
2. Dimming switch to reduce night glare
3. Cylinder number (of the temperature being displayed) is prominently displayed at the top.
4. EGT and CHT readings
5. Pilot controlled alarms.
6. Temperature can be displayed in degrees Fahrenheit or Centigrade
7. Coupled with J.P.I’s famous super accurate fast EGT/CHT response probes.
8. Manual and Auto switch - when the toggle switch is in the Manual position the EGT Scanner will display the current cylinder.
9. Normal leaning is accomplished on the leanest cylinder in the Manual mode which can be found by peaking each cylinder and noting its fuel consumption.
10. In automatic mode temperature of each cylinders will be displayed every four to five seconds in descending order.
11. Alarms are part of the Automatic mode.
12. Day and Night LED brightness options.

So if you are looking for a EGT Probe that provides the basics with a high degree of accuracy, Classic Scanner EGT Gauge System is the one you would be looking for. More information here:

3 months ago

JPInstruments Serve The Quality Avionic Instruments

Avionic InstrumentsAvionics is all about unique and successful application designs and processes that take your capabilities to new heights add to your strengths. But then again, avionics components must match your unique requirements perfectly. For, without proper aircraft avionics, communication and navigation systems – irrespective of weather conditions - all that you can expect is going down in flames! You cannot fly leaving behind all that are critically important.

JPInstruments has a long-standing reputation for keeping your flight safe and enjoyable with its avionic instruments. Assembling, upgrading, calibration or in-house testing – behind the laurels so far achieved by JP Keyspan USB are entirely the credits of the engineering and manufacturing crew whom we brought together over the years. And yet, we take credits for nothing apart from bringing the wide grin on the face of the aeronauts!

Design-jobs are more complex by nature and can’t be achieved in the cookie-cutter method. They are unique in their own ways - all of them – and their demands are varied; some even requiring custom solutions. Without a complete manufacturing control, it can’t be ensured that toughest specifications will be met, let alone exceeding them. Our years-long reputation as the industry-leader is because of our engineering prowess, fine-tuned to deliver exact specs and configurations as per your demands. Our history of reliable, quality products proves that!

Currently, our instruments are in use in the general, commercial and military aircraft platforms, which has kind of set up a trend of incorporating JP cockpit instrumentation products into every major aerospace EGT Gauge system integrator using analog instrument systems. They come as a combination of highest degree of reliability and unique engineering and manufacturing capabilities. All these gel into one single concept - Make our avionics components your solution of choice! When your aircraft electronics need to operate at optimum levels, it thus becomes critically important to get in touch with JP Instruments!

The areas we undertake are aircraft servicing, radio and other instrument replacements, repairing quickly and efficiently existing instruments that were supplied or came installed – this way, we bring you an one-stop solution for your aircrafts, including helicopters. When you want a safe and secured way to fly in all weather conditions, JP Instruments ensure that you do!

Besides the auto pilots, electronic/ pilot-static indicators, fuel and gyroscopic instruments, remote compass and stall-warning systems, JP Instruments also undertake installations and repair of cockpit-mounted electronic time pieces; electrical, communications; radio and ILS systems and we do all that exceptionally well! Even satellite telephone systems, aircraft precision products, EGT monitors and the rest of the aircraft digital instruments! If you are not satisfied with your engine data management systems and GPS-assisted direction finding, get in touch with JPI for its high quality, state-of-the-art and highly reliable services. Besides, you are definitely going to like our EDM-900, certified, colour engine management system, which comprises high-end JPI products bundled together in one spectacular "all-in-one" instrument!

3 months ago

EGT CHT Gauge - Primarily Designed For Aircraft

Fuel Scan 450 TwinGranted that Exhaust Gas Temperature (EGT) and Cylinder Head Temperature (CHT) have applications in auto industry, the sensor probes and instruments designed to capture and display these temperatures were primarily designed for use in aircraft.

The Exhaust Gas Temperature (EGT) sensor or probe is placed in each exhaust pipe of the aircraft, roughly 4 to 6 inches from the cylinder head. These probes read the temperature of the gas as it leaves the cylinder. The exhaust gas temperature is not uniform and varies depending on the power setting, ambient air temperature, altitude and cylinder compression.

Other factors that come into play and have a bearing on the exhaust gas temperature include spark plug ignition timing and cylinder leakage i.e. compression loss. To an expert, the EGT sensor offers a peephole into the combustion process taking place within the cylinder. Usually, the health of the aircraft engine is not based on one particular EGT reading but an average. So if the overall average is abnormally high or low then you have a problem.

In fact for a pilot, it is the bigger overall picture that is drawn by the relative value of EGT i.e. relative to other cylinders and also relative to performances over normal days as well as the way that EGT responds to changes in the fuel-air mixture that are of primary interest.

The single most important reason to pay attention to the EGT reading is to know whether or not your engine is running and this is especially true in a multi-engine aircraft. Contrary to belief, in a multi-engine aircraft the pilot may not immediately realize that one of the engines is not working. This is because other than the EGT, all other displays will read normal.

For example, the aircraft RPM indicator, oil pressure, manifold pressure and even oil pressure and oil temperature will all read normal. A look at the EGT on the other hand will instantly tell the pilot which engine has stopped functioning (because of the fast reducing temperature reading).

Apart from knowing whether or not the aircraft engine is functioning and overall health of the engine, the other important use of the EGT Probe is to help you perfect your aircraft lean mixture. When you pull the fuel-air mixture control back, the F/A ratio will reduce while the EGT increases. As the F/A ratio continues to decrease, it will reach a point when the EGT begins to back down. This is the point at which the ratio of air-to-fuel is at its optimum best.

Cylinder Head Temperature or EGT Gauges for short, measures temperature at one spot on the cylinder head – usually the threaded boss in the cylinder. The difference between the EGT and CHT reading is usually between 30 and 60 degrees and therefore the CHT helps confirm EGT readings. Of course the difference between the EGT and CHT will also depend on the type of (carbureted or fuel injected) engine with the fuel injected engines displaying a bigger temperature difference.