The positions of the instruments on this helicopter seem to change for pretty much every model, so I tried to combine them all into one.

• The COMM XMT buttons will transmit voice audio as long as you tuned your radio channel and RADIO MASTER is on.
  
• KNOTS is your airspeed in... knots.
  
• ADI is your artificial horizon. It may look a little different from what you're used to. The line drawn between the tips of the split needle is the horizon.
  
• RMI is your radio/gyro compass. It combines your compass (needle facing north, pretend the heading displayed isn't negative) with your VOR indication (ghost needle that flickers for a shorter period of time). More on VOR later.
  
• FLT INST PWR will enable the instrument power inverters (lets em move round, be powered). It's a simulated feature that's only really here for realism, and the ability to forget it or experience a failure (wink wink)
  
• WARNS just means a bar segment representing the different warning lights you can experience. They are listed in order from top to bottom when you hover over the instrument ingame.
  
  • 10 MIN. FUEL lights up when you have 10 minutes of fuel remaining. IRL it's for 30 minutes, but blame the game's fuel consumption.
    
  • ENG CHIP lights up when the engine temperature goes over 110 degrees C. It will only turn off once you perform "maintenance." (press the button hidden in the engine behind the cowling)
    
  • TRANS CHIP lights up when the transmission is close to failure. You will need to run the helicopter for quite a while to see this fault organically. Behind the right side transmission cowling (behind the cockpit) is the panel you use to perform "maintenance" as well as see the current transmission wear. The rate at which the transmission wear occurs is increased with higher collective load and rpm, so if you want it to last longest i'd advise against aerobatics.
    
  • INST PWR FAILURE is inop. in its current state. I haven't gotten around to adding it yet, but it's a quick fix so hopefully won't take long.
    
  • ROTOR BK. ON will light up when... the rotor brake is on.
    
  • GEN WARN will light up when the output of the generator is below the level needed to provide sufficient power.
• RRPM (x100) is your rotor rpm... times 100.
  
• ALT is your barometric altitude in feet, more on "barometric" later.
  
• TURN is your turn and slip indicator. The ghost needle facing up is your turn indicator, between the two tick marks on the top indicates the standard 3 degree per second rate of turn. The ghost needle facing down is your slip/skid indicator. In real aircraft this is usually a form of ball level, so I spent way too much time and effort in making an accelerometer to display this information in the most physically accurate way possible. Unfortunately, it is now too physically accurate, and only shows how inaccurate the game's inertia and aerodynamics are. It's almost useless and only there to say it's there. (it was apparently broken while writing this, it's fixed now)
  
• CYL. TEMP. (C) is the cylinder head temperature, in Celsius. Make sure it doesn't go above 115 degrees.
  
• BATT & GEN is your master battery switch, combined with the generator switch. The only time you would need these to be separately controlled are on startup, so to save space I combined them into one.
  
• IGNITION & FUEL PUMP is essentially your engine on/off switch. While it's on, hold 3 to start the engine. Flipping the switch off will choke the engine.
  
• MAN is your manifold pressure gauge. On these old radial aircraft, this was the primary way to show the engine's current throttle input. Higher number means higher throttle. When the engine is off, the gauge will read the current ambient air pressure in inches of mercury.
  
• ERPM (x100) is the engine rpm... times 100.
  
• VERTICAL SPEED is your vertical speed in feet per minute, times 1000. It is derived from barometric altitude.
  
• RADIO ALTITUDE FEET is your radio altimeter... in feet. BEWARE tilting the helicopter too far to the left will cause the radio altimeter to read 0 or near 0 as it conflicts with the floor of the helicopter. Fly normally.
  
• VHF NAV shows the current frequency inputted into the VOR antenna. More on VOR later.
  
• TUNE VHF has two uses. Tapping it quickly will set the VHF NAV frequency (inputted from the center console keypad), and holding it for more than one second will set the OBS (inputted from the same keypad). More on OBS later.
  
• TUNE COMM has two uses aswell. Tapping will set your voice radio channel for talking to ATC, and holding for over a second will set your reference pressure. More on reference pressure later. Both are still inputted from the same keypad.
  
• CDI is your course deviation indicator. This is to do with radio navigation, and will therefore be explained later.
  
• ATC TRANSP shows your current transponder squawk code, inputted with the keypad directly under the center of the instrument panel. More on how the transponder works later.
  
• PARKING BRAKE is a nice departure from the radio stuff. It's your parking brake. It locks your wheels.
  
• REF. PRES. shows your current set reference pressure. More on reference pressure later.
  
• COMM displays the current ATC radio channel you're tuned to. I already explained how to tune so I won't again.
  
• TAIL WHEEL LOCK locks the tail wheel. What a surprise. Very useful.
  
• FUEL QUANTITY is your fuel quantity, in liters. Because of how thirsty pipes are now the tanks will almost instantly be sucked to half capacity. I would recommend refueling right after spawning to get the most range.
  
• OBS shows the current selected OBS. More on OBS later, as usual.

• LAND HOVER LTS enables the downward facing spotlight on the left landing gear strut. For the full landing light suite, press 4 as well to enable the look-controlled forward facing spotlight.
  
• ROT. LT enables the red rotating anti-collision beacon on the top of the tail.
  
• EMER CABLE CUTAWAY disconnects any cables connected to the cargo hook on the underside of the helicopter. It also sends an on/off signal the cable connector.
  
• RADIO MASTER enables the ATC talk radio.
  
• CABIN HEAT enables the cabin heater, for winter or arctic operation.
  
• PITOT HEAT enables the simulated pitot tube heater. If you're in the right conditions without this heater enabled, the simulated static pressure port will ice over and you will experience anomalous altitude and airspeed information.
  
• EXTERIOR LIGHTS (1) can be toggled either off or on. Off means the lights will be dim, and on means they'll be bright.
  
• EXTERIOR LIGHTS (2) is a push button that cycles the exterior lights between three modes; Steady, flash and off.
  
• INST LTS toggles the instrument panel backlights.
  
• CONSOLE PANEL LTS toggles the backlights on the center console keypad and throttle indication. Very useful.
  
• CABIN LTS is a push button that cycles the cabin lights between three modes; White, red and off.
  
• ROTOR BRAKE enables the... rotor brake. It will also automatically disconnect the clutch as a safety mechanism.

On the wall up behind the pilots, on the pilot's side, there is a small triangular button called CKPT. DOME LT. It cycles between three modes; White, red and off.

Reference pressure in short is the ambient air pressure at which the altimeter reads zero.

The standard reference pressure when none is given is 29.92 inHg (inches of mercury. It's an old measurement of pressure), and therefore inputting zero as the reference pressure sets it to 29.92 as default.

ATC may give its planes the area's current nautical height, called QNH, which represents what the air pressure would be at sea level. This is important in the real world when following approach charts or ATC commands, as the QNH where you took off may not be the same as the QNH where you're landing.

Not used so much today is field elevation, or QFE. This is the air pressure at the airfield level.

Inputting the QNH or QFE as the reference pressure will orient the altimeter either to the ocean level or to the ground level of the airfield. QNH is usually used for higher flight levels, and QFE is usually used for approaches, patterns or landings, anything closer to the ground.

You will almost never need to use this ingame. It's there purely for realism and roleplay purposes.

VOR, or VHF Omnidirectional Range, or Very High Frequency Omnidirectional Range, is an old form of radio navigation developed in the 30s or 40s, not sure which.

In the real world, ground based navaids (beacons) transmit a signal in all directions which a receiver on the aircraft can tune to. The beacons also transmit a second signal, which has a specific phase shift relative to the first signal that represents the aircraft's current bearing to the beacon. Obviously, we do not have that kind of complexity ingame, nor does anyone want that kind of complexity ingame.

Instead, I have an antenna on the aircraft that cycles through 3 different radio channels, and a ground beacon with three different radios set to those channels. The antennas are placed in such a way that, based on the signal strength between the radio antennas, the aircraft's bearing to the beacon can be calculated by translating the signal strength to distance.

This bearing to the beacon, only found when tuned to the right channel, is then displayed as the flashing ghost needle on the RMI mentioned earlier in the instrument section. Tune to the frequency of a beacon, and the needle will show the way to it.


The OBS, or Omni Bearing Selector, is a way to choose the bearing from which you want to approach a nav beacon. The CDI, or Course Deviation Indicator, indicates your deviation from the course set out by the OBS.








Examples:
Say you tune to a beacon. You are directly southwest from this beacon. You set the OBS to 90 degrees. The CDI ghost needle (facing down) will deflect to the left. This shows that you are to the right of the course you want to follow. ->
Now imagine you're directly north of this beacon. You set the OBS to 180 degrees. The CDI ghost needle (facing down) would stay in place, as you are currently following the course directly south. <-

If this is confusing, I would recommend looking up a real world video example. My mspaint drawings aren't exactly top notch. The orientation of the text inside the CDI shows the orientation of the instrument relative to the map.

When the aircraft detects it's been seen by radar, It will transmit it's current altitude in 100 foot increments as well as it's "squawk" code, a unique identifying code that ATC can use to differentiate different aircraft on their radar scopes.

In the real world, this would be classified as a Mode C transponder as it transmits altitude along with the aircraft's squawk code. Mode A transponders only transmit squawk code.

To make both modes compatible with the same radar system, I have the transponder set to transmit the squawk code in channel 1 and altitude in channel 2. Information is sent for a single tick to avoid interference.

Mode S transponders are a different beast that I don't want to have to deal with. TCAS or some ♥♥♥♥.

I have built a secondary ATC radar that uses the transponder, so I know it's possible.

That horizontal ghost needle is for ILS. Yes, ILS in a helicopter. I originally made this CDI logic for a Douglas DC4 I was working on and will probably never finish, so the function of ILS is still built in. It requires a different kind of beacon, one I haven't released yet, so ignore it for now please.

Island beacons

Sawyer beacons

Meier beacons

Harrison AB ATC Tower