Introduction
The direction gyro in default MSFS (up to at least SU10) does feature drift, but it does not seem to be doing so correctly.
RealGyro gives you realistic drift on the Direction Gyro.
Amongst other things, this would enable grid navigation and polar flights without GPS.
Features
· Realistic Direction Gyro drift
· Pause detection in flight
· For (almost) all aircraft, see limitations below
· Runs in the background
Installation
Extract to a folder of your choice.
Run the RealGyro executable. You want to make a shortcut.
Instructions to use
Disable default Gyrop Drift in MSFS (OPTION -> ASSISTANCE OPTIONS -> AIRCRAFT SYSTEMS)
Run MSFS, then start RealGyro. The interface appears and the add-on should work instantly and requires not operation.
Use of the DG in flight is not different from before. Also shortcut ‘D’ for alignment to the magnetic compass works.
Limitations
Some aircraft present limitations. Known issues are listed below. Warnings for these aircraft may appear in the GUI.
PMDG DC-6
Unslave the Directional compass from the magnetic compass. Then RealGyro works fine. The gyropilot will be able to follow the RealGyro.
PMDG B737
The PMDG B737 uses internal modelling. Uncertain if / how drift / precession are modelled.
Wing42 Boeing 247D
The Boeing 247D uses its own local variables (LVAR) to control the DG and this cannot be altered externally. Realgyro may continue to run but has no effect.
Background
RealGyro drift is the sum of three individual components:
· Real precession – A small and random drift due to mechanical imperfections, electrical power, friction, rotations. Typically this is in the order of 1°/hour.
· Apparent precession – A noticeable drift due to rotation of the earth, varies from 0°/hr near the equator to 15°/hr at the poles.
In real-world Directional Gyros this is offset by a ballast weight at a certain latitude-of-use. For RealGyro this is set at 30° Latitude, giving acceptable drift across common latitudes.
· Transport precession – A noticeable drift due to the aircraft moving over the earth. Varies with speed and latitude.
For details refer to AFPAM11-216, March 2001.
Credentials
This add-on is brought to you by CelestialNavigator, also creator of:
- Celnav add-on
- Driftmeter add-on
- Radio Range navigation add-on (standalone and built-in Boeing 247)
- Massive world points of interest collections
- Boeing 247D exhaustive checklist
Eric van der Veen, Oct. 2022
52.1°N, 4.3°E (approximately)