The Instrument Panel

An overview

Airspeed Indicator Attitude Indicator Altimeter Vertical Speed Indicator Low Voltage Indicator Fuel Low Indicator Main Rotor Temperature or Pressure Caution Indicator Starter Warning Light Turn And Slip Indicator Direction Indicator Combined Engine & Rotor RPM Indicator Manifold Air Pressure Gauge VOR / ILS Indicator Circuit Breakers Fuel Quantity Gauge Fuel Pressure Cylinder Head Temperature Oil Pressure Gauge Oil Temperature Battery Charging Ammeter Engine Hours Meter or Datcon Chronometer or Stopwatch Clutch Switch Alternator On / Off Switch Fuel Boost Pump On / Off Switch Auto Engage System Activation Light Clutch Disengaged Warning Light Magneto Switch Circuit Breakers GPS Nav Comm Instrument Light Dimmer Panel Light Dimmer Panel Light On / Off Swich Trim Selector Carbon Monoxide Detector Mixture Control Mixture Control Tai Rotor Chip Light Rotor Low RPM Light Low Rotor RPM Test / Mute Button Fuel Shut Off Valve Battery Master Switch Position Lights On / Off Switch Beacon On / Off Switch Automatic Clutch Engagement Switch Hot Mic Switch
This is a typical H300 CBi instrument panel.
Move the mouse over the panel for a description of the instruments.
Click on an item on the panel for a more detailed explanation.

Air Speed Indicator

Displays Airspeed in knots (this one is also calibrated in MPH). Measures difference between pitot pressure and static pressure and displays the difference as airspeed.

Attitude Indicator or Artificial Horizon

Gyroscopic instrument which indicates rates of pitch and roll. When correctly aligned by the pilot indicates steady state pitch and roll with respect to the horizon.


Indicates height above a pilot set datum, if this datum is set to Sea Level then altitude is displayed. Works by sensing static air pressure and displaying the difference between that and the datum as an altitude in feet (some are calibrated in meters).

Low Volts Warning Light

Illuminates when the bus voltage is less than a predetermined value.
Usually indicates charging system failure, although may not illuminate immediately if the battery is very strong.

Fuel Low Caution Light

Indicates 1 Gallon remaining.

Tail Rotor Chip Light

Illuminates is metal particles are found in the tail rotor gearbox.

Low Rotor RPM Warning Light

Illuminates if the rotor RPM falls below a manufacturer determined Limit.
In the case of the 269CBi it flashes below 440RRPM and illuminates continuously below 390 RRPM.

Starter Warning Light

Illuminates while a voltage is applied to the starter motor. Should be on while the starter button is depressed, off at all other times.

Low Rotor RPM Horn Test / Mute Button

On the ground can be used to test the low rotor RPM horn.
In flight can be used to silence the horn when it sounds.

GPS Nav Comm

Three things in one box for this one.
  • Global Positioning System
  • Navigation Receiver
  • Communications Receiver

Clutch Engage / Disengage Switch

This switch controls the clutch, which is used to disengage the rotor system in order to facilitate engine startup and shutdown without a load on the engine.

Engine Oil Temperature Gauge

Inidcates the temperature of the oil in °C.
An excessively high or low temperature may be an indication of impending failure.

Fuel Pressure Gauge

This aircraft has a fuel injection system and as such requires the fuel to be fed to the servo injector unit under pressure.
The gauge is calibrated in Pounds per Square Inch (PSI).

Turn And Slip Indicator

Really two instruments in one.
The Slip indicator is the little black ball. It indicates whether the aircraft is in balance (at cruise airspeeds).
The Turn indicator is the aeroplane, when the wings of the aeroplane are aligned with the diagonal white lines this indicates the the helicopter is performing a rate one turn (3° per second).

Manifold Air Pressure

This gauge indicates air pressure in the inlet manifold. It is used as an approximate indication for engine power. Calibrated in inches of mercury, which is one of many ways to describe a pressure.

Engine Oil Pressure

Displays the oil pressure inside the engine in PSI.

Direction Indicator

Gyroscopic instrument which when sychronised with the Compass indicates heading.

Fuel Quantity Gauge

Displays the fuel quantity remaining in the fuel tank(s). This one is calibrated in US Gallons.

Combined Engine And Rotor RPM Gauge

Really two gauges in one.
The long needle measures Engine RPM (ERPM) along the outer scale.
The short needle marked with an R measures Rotor RPM (RRPM)on the inner scale.
Both scales are calibrated in Revolutions Per Minute.

VOR/ILS Indicator

This instrument indicates radial postion from a ground based beacon.
It also has a glidelope indicator which is be used when flying an ILS.


Measure current flow into or out of the battery. It is calibrated in AMPs.

Cylinder Head Temperature

Inidcates the temperature of the cylinder head in °C.
An excessive temperature may be an indication of impending failure.

Circuit Breakers

Circuit Breakers can be thought of as resettable fuses.
They can be reset once only, if popped in flight.

Mixture Control

Controls fuel:air mixture. Fully in is rich, fully out is lean (cut off).

Trim Selector

Controls which pilot has control of the electric cyclic trimmer. Whichever side the trim switch points to has control.

Carbon Monoxide Detector

Not a mandatory item, but a sensible one. CO2 is colourless, odourless and can kill. Indicator will turn black if CO2 is present.

Vertical Speed Indicator

Indicates rate of climb or descent in hundreds of feet per minute. Works by sensing static pressure and displays rate of change of pressure as a rate of change in altitude.

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