AS9120B, ISO 9001:2015, and FAA AC 0056B ACCREDITED

Engine Performance Instrumentation in Aviation

As the capabilities of modern aircraft continue to improve, so does the need for high-reliability instrumentation. These instruments, which may either be mechanical or electrical depending on the age of the aircraft, give pilots critical information about metrics such as altitude, airspeed, direction, and other such information. While instruments such as the altimeter and artificial horizon play a vital role in operations, the less appreciated engine-performance instruments also provide essential real-time data to help ensure safety. In this blog, we will detail the several engine-performance instruments so that you may have a better understanding of their design and function.

Oil Pressure Gauge

Jet and reciprocating aircraft engines both contain numerous components that are regularly in motion, with constant exposure to heat and friction. As such, these elements require a continuous and adequate amount of lubrication in the form of aircraft oil. Oil gauges are simple mechanical devices that read and project the oil system's pressure at all times during the flight. These meters don't require any form of electricity, meaning their operation does not cease during moments of electrical malfunctions.

The gauge features incremental readings, much like a speedometer, and most models contain a red line near the low and high end to alert the pilot as to dangerous levels. If the pilot notices a sudden drop in oil pressure or a period of fluctuation, they should suddenly reduce power in order to diagnose the situation. Should the engine not receive adequate lubrication for an extended amount of time, several bearings may seize and render the system unserviceable.

Oil Temperature Gauge

In an ideal system, temperature and pressure increase in a linear and predictable manner. Thus, changes in oil temperature may correlate to some degree with oil pressure. Additionally, if the oil circulating through the engine reaches extremes in either direction, it will negatively impact performance. To aid pilots in quickly discerning oil temperature, the gauges are commonly equipped with several colored zones. Red, which indicates a deviation from the norm that must be immediately addressed, is found on the high and low end of the temperature range. Some gauges also feature a yellow zone, which alerts the pilot that the temperature is reaching extremes. The green zone, which is commonly from 170-220 degrees F, indicates optimal operating temperature. While it is critical to keep an eye on this metric, fluctuations in temperature are common and may not always represent a problem.


Both reciprocating and gas turbine engines are equipped with a tachometer, which quantifies the revolutions per minute (RPMs) of the crankshaft or compressor section. Since each engine may be operating at different RPMs, there must be a tachometer equipped alongside each engine. Observing RPMs, pilots may modulate the power to achieve the most efficient output.

Fuel Pressure Gauge

Of the various quantities measured by the engine instrumentation system, arguably none are more important than the fuel pressure. While there are several designs that may be implemented in fuel quantity measurement, the two most common are mechanical and electronic-type. Mechanical-type measurement components use a floating device placed in the fuel tank that directly measures fuel level. Meanwhile, electronic-type gauges take advantage of the dielectric nature of fuel to measure capacitance and, in turn, fuel level without the need for a float-operated transmitter.


Regardless of your aircraft instrumentation needs, Hardware Orbit has you covered with an expansive inventory, competitive pricing, and rapid lead times. Whether you are in need of a new, obsolete, or hard-to-find item, our team of experts is available 24/7x365 to provide you with a 15 minute-or-less quote. To begin, simply submit an RFQ form for any product you are interested in, including as much detail about your requirements as possible. Choose Hardware Orbit to source the necessary components for your next project, and experience the evolution of part procurement.


Recent Twitter Posts

Semiconductor's Certifications and Memberships
The only independent
distributor with a
  • All orders are fulfilled in the USA.
  • All shipments must comply with U.S.A export laws.
  • No exceptions.
Fallen Heroes Fund

“We Proudly Support Intrepid Fallen Heroes Fund that serves United States Military Personal experiencing the Invisible Wounds of War : Traumatic Brain Injury (TBI) and Post Traumatic Stress (PTS). Please visit website ( and help in their valiant effort”.

Thank You for Visiting.

We Hope that You Will Visit Us Again the Next Time You Need NSN Parts and Make Us Your Strategic Purchasing Partner.

Request for Quote