HUD_VerticalSpeed

HUD_VerticalSpeed inspector.

Purpose and Role

The HUD_VerticalSpeed instrument displays aircraft vertical speed (rate of climb/descent) on a variometer dial. It reads the vertical component of velocity from the aircraft controller, converts it to feet-per-minute, and rotates an indicator needle to show climb/descent rate. This instrument provides real-time feedback on altitude change rate for navigation and flight planning.

Data Source and Update Mechanism

The instrument continuously reads:

  • Velocity.y from AircraftController.Velocity (vertical speed, m/s)
  • Converts to feet-per-minute: feetPerMinute = velocity.y * 196.85f
  • Updates every frame in LateUpdate()
  • Clamps displayed rate to max indicated speed range

Configuration Properties

  • Hand (Transform) - The rotating vertical speed indicator needle

    • Moves up for climb, down for descent
    • Can be Transform (3D) or RectTransform (UI)
    • Rotates around Z-axis based on climb rate

  • Degrees Per Unit (float) - Rotation degrees per 100 ft/min

    • Default: -8.214 degrees per 100 ft/min
    • Negative indicates counter-clockwise rotation
    • Scaled by climb rate in 100 ft/min increments

  • Max Indicated Speed (float) - Maximum displayed climb rate in units of 100 ft/min

    • Default: 20 (represents 2000 ft/min max)
    • Typical range: 10-30 (1000-3000 ft/min max)
    • Higher values allow display of higher climb rates
    • Climb/descent rate clamped to this limit

Vertical Speed Measurement and Display

Vertical Speed Convention

Positive (climbing):
+1 m/s = +196.85 ft/min
+2 m/s = +393.7 ft/min
+5 m/s = +984.25 ft/min

Negative (descending):
-1 m/s = -196.85 ft/min
-2 m/s = -393.7 ft/min
-5 m/s = -984.25 ft/min

Needle Rotation Calculation

FeetPerMinute = Velocity.y * 196.85f
ClampedFPM = Clamp(FeetPerMinute, -maxIndicatedSpeed*100, +maxIndicatedSpeed*100)
HandRotation = ClampedFPM * degreesPerUnit * 0.01f

Example with defaults:

  • Max indicated speed: 20 (2000 ft/min)
  • degreesPerUnit: -8.214 degrees per 100 ft/min
  • Climb 500 ft/min: Rotation = 500 * (-8.214) * 0.01 = -41.07°
  • Descend 500 ft/min: Rotation = -500 * (-8.214) * 0.01 = +41.07°

Aircraft Source Configuration

  • Manual Source (default) - Directly assign aircraft in inspector
  • Vehicle Changer Source - Automatically switches to active vehicle

Setup Instructions

Basic Setup

  1. Create vertical speed indicator visual (dial showing ft/min scale)
  2. Create hand/needle showing climb/descent
  3. Assign hand Transform to Hand property
  4. Set Max Indicated Speed (20 typical for 2000 ft/min max)
  5. Set Degrees Per Unit (typically -8 to -10 for reasonable needle movement)
  6. Assign target aircraft controller
  7. Test by climbing/descending and observing needle movement

Calibration

  1. Level flight (zero vertical speed) - needle should be centered
  2. Steady climb - needle should move up proportionally
  3. Steady descent - needle should move down proportionally
  4. Maximum climb - needle approaches top limit
  5. Maximum descent - needle approaches bottom limit
  6. Adjust degreesPerUnit if needle movement too fast/slow

Public API

Properties (Read-only)

All properties configured in inspector.

Common Usage Patterns

Basic Climb Rate Monitoring

HUD_VerticalSpeed variometer = GetComponent<HUD_VerticalSpeed>();

// Automatically updates with aircraft vertical speed
// No additional code needed for basic operation

Climb Rate Limits

AircraftController aircraft = targetAircraftController;
float climbRateFtMin = aircraft.RateOfClimbFtMin;

// Warn if exceeding structural limits
if (Mathf.Abs(climbRateFtMin) > 4000f)
{
    // Excessive climb/descent rate - structural damage possible
    Debug.Log("WARNING: Excessive climb rate!");
}

Performance Monitoring

// Track best climb rate
float maxClimb = 0f;
float maxClimbSpeed = 0f;

void Update()
{
    float climb = targetAircraftController.RateOfClimbFtMin;
    if (climb > maxClimb)
    {
        maxClimb = climb;
        maxClimbSpeed = targetAircraftController.AirspeedKTS;
    }
}

Integration with Other Systems

  • AircraftController - Source of vertical speed data
  • VehicleChanger - Optional automatic aircraft source switching
  • HUD_Instrument - Base class for instrument functionality
  • Flight Planning - Can be used for altitude target management
  • Autopilot - Can provide vertical speed commands

Real-World Context

Climb/Descent Rates

Typical aircraft vertical speeds:

  • Slow climb: 100-300 ft/min
  • Normal climb: 300-1000 ft/min
  • Max climb: 1000-3000 ft/min (varies by aircraft)
  • Slow descent: 100-300 ft/min
  • Normal descent: 300-500 ft/min
  • Emergency descent: 500-2000 ft/min
  • Max descent: 2000-5000 ft/min possible

Variometer (Vario) Instrument

The variometer (vertical speed indicator) is used for:

  • Altitude management - Monitoring climb/descent rates
  • Fuel planning - Adjusting climb rate affects fuel burn
  • Traffic avoidance - Maintaining assigned altitude
  • Weather navigation - Finding better climb conditions
  • Glider flying - Finding thermal updrafts (visual feedback)

Excess G Considerations

Rapid vertical speed changes can exceed aircraft structural limits:

  • Positive G limit: Typical 3-6G depending on aircraft
  • Negative G limit: Typical 2-3G (less than positive)
  • Abrupt maneuvers can cause "G-loads" exceeding limits
  • NWH system doesn't enforce these limits automatically

Troubleshooting

Needle Not Moving

  • Verify hand Transform is assigned
  • Check targetAircraftController is valid
  • Confirm aircraft is climbing/descending (velocity.y != 0)
  • Verify degreesPerUnit is not zero

Needle Movement Too Slow/Fast

  • Adjust Degrees Per Unit value
  • Typical range: -4 to -12 degrees per 100 ft/min
  • More negative = more sensitivity
  • Less negative = less sensitivity

Needle Inverted (up means down)

  • Flip sign of Degrees Per Unit (-8.214 ↔ +8.214)

Needle Stuck at Maximum/Minimum

  • Check max indicated speed setting
  • If aircraft climbing/descending faster than max, increase maxIndicatedSpeed
  • Verify climb rate is within reasonable bounds