The JSV Flight Logger captures one of the most comprehensive telemetry datasets of any virtual airline tracking tool. This article explains exactly what data is collected and how it’s used.
Data Collection Overview
The app reads data from your simulator once per second via:
- MSFS 2020/2024: SimConnect API — direct in-process data access, no additional plugins needed.
- X-Plane 11/12: UDP DataRef protocol — 77 DataRef subscriptions over port 49000.
Complete Data Point List
The following table lists every data point captured. Data availability depends on the aircraft model and simulator.
| Category | Data Points |
|---|---|
| Position | Latitude, longitude, altitude MSL, altitude AGL, magnetic heading, true heading |
| Speed | Ground speed (GS), indicated airspeed (IAS), true airspeed (TAS), Mach number, vertical speed |
| Attitude | Pitch, bank angle, normal G-force |
| Ground State | On ground flag, gear handle position, parking brake |
| Engines (per engine ×4) | Running status, N1 (fan speed), N2 (core speed), EGT (exhaust temperature), fuel flow, oil pressure, oil temperature, reverser deployed, engine anti-ice |
| Fuel | Total fuel weight (converted to lbs) |
| Controls | Flap position, spoiler position, elevator trim, aileron trim, rudder trim |
| Weight & Balance | Total aircraft weight, centre of gravity (%) |
| ATC / Navigation | Transponder code, assigned gate, assigned runway, GPS next waypoint (name, distance, course), ILS localizer deviation, ILS glideslope deviation, NAV frequency, COM1 frequency, COM2 frequency |
| Lights (7 types) | Landing, strobe, navigation, taxi, beacon, logo, wing |
| Autopilot | AP master on/off, selected heading, selected altitude, selected speed, selected VS, autothrottle engaged |
| Systems | Autobrake setting, seatbelt sign, no smoking sign, pitot heat, windshield anti-ice, APU running, battery master, main door open, hydraulic pressure, cabin altitude, cabin VS |
| Weather | Wind speed, wind direction, wind gusts, OAT, barometric pressure (QNH), visibility, precipitation type, cloud base altitude, structural ice accumulation |
| Time | Simulator Zulu time |
Performance Snapshots
The logger doesn’t just record raw data — it analyses it to create performance snapshots at key moments:
Continuous Tracking
Throughout your flight, the following min/max values are tracked:
- Maximum altitude reached
- Maximum indicated airspeed
- Maximum Mach number
- Maximum and minimum G-force
- Maximum climb rate (fpm)
- Maximum descent rate (fpm)
- Minimum fuel remaining
Departure Snapshot
Captured when you start the flight at the gate. Records initial conditions: gate name, fuel load, weight, weather, and pressure setting.
Takeoff Snapshot
Captured at the moment of lift-off. Records: IAS at rotation, pitch angle, flap setting, wind conditions, and calculated headwind/crosswind components using trigonometric wind decomposition relative to your runway heading.
Cruise Statistics
Calculated as running averages during the cruise phase: average altitude, IAS, Mach, fuel flow, OAT, and total cruise duration. These help you understand your cruise efficiency.
Approach Snapshot
Captured when entering the final approach phase. Records ILS deviations (localizer and glideslope in dots) and performs a stabilised approach check at 1,000 ft AGL:
- ✅ Gear must be down
- ✅ Flaps must be extended (> 0%)
- ✅ Vertical speed must be between 0 and −1,000 fpm
If any condition fails, an unstabilised approach event is logged.
Touchdown Snapshot
Captured at the exact moment of landing. Records: vertical speed (fpm), ground speed, pitch, flap and spoiler positions, and wind data with headwind/crosswind calculation. Also checks for bounce detection — if the aircraft becomes airborne again within 5 seconds of touchdown.
Arrival Snapshot
Captured when you reach the gate (On Block). Records: fuel remaining, total fuel used, block time, and gate assignment.
Data Usage
All telemetry and performance data is:
- Sent with your PIREP — admin staff can review your detailed flight data.
- Visible on your profile — landing rate, score, and key metrics appear on your pilot page.
- Used for scoring — the rule engine evaluates telemetry in real-time for violations.
- Available for analytics — airline-wide performance statistics and trends.