From IGC to Black Box

To understand how the Vector Vario records, protects, and signs your flight data
1. What are flight data for?

Flight data describe objectively and precisely what happens in the air at every moment, whether it is to:

  • validate a flight on XContest;
  • analyze a flight or performance;
  • understand an incident or accident.
2. The IGC standard

The Vector Vario records all flight information in an IGC file, a standard format defined by the FAI/CIVL. This file contains:

  • a header detailing the pilot, aircraft, and flight recorder used;

  • des timestamped points every second, indicating position and altitudes (barometric and GNSS);

  • a signature at the end of the file, ensuring the authenticity of the data.

Such a file is necessary and sufficient to validate a flight on XContest but lacks detailed information to understand flight dynamics or analyze atmospheric conditions accurately.

3. IGC+ enhanced by the Vector Vario

The Vector Vario adds the following additional data, measured and calculated precisely:

  • Attitude: heading, pitch, and roll angles of the aircraft;
  • Flight dynamics: IAS and total acceleration;
  • Environment: 3D wind (horizontal and net components), air temperature, and relative humidity.

These data allow:

  • Des Very detailed flight analyses; très détaillées ;

  • Precise study of weather conditions and their evolution;
  • Des Advanced visualizations (e.g., on the right a track with 3D wind in Google Earth);

  • Better understanding of circumstances leading to an incident or accident ;

These additional data do not prevent the IGC file from being validated on XContest.

4. A Final signature despite unexpected termination

To guarantee authenticity, recorded data must be signed. When the flight ends normally, the device simply adds this signature at the end of the IGC file. However, in case of an unexpected stop (malfunction, impact…), the file remains incomplete, potentially corrupted, and unsigned.

A system is therefore required to ensure that the data are correctly recorded and signed, no matter what happens.

5. The temporary double-signature solution

The Vector Vario’s strategy to record all data and ensure it is always signed consists of:

  • Recording every second the new data in the IGC file;

  • Saving every second the new signature in a separate file, along with the line number of the last data it validates in the IGC file.

This signature file keeps only the two most recent signatures and alternately updates them. In this way, the data recorded every second in the IGC file are always accompanied by a valid signature, even in case of an unexpected device stop. All scenarios are thus covered:

  • In the vast majority of cases, the Vector Vario shuts down normally, adds a signature at the end of the file, and the signature file is deleted.
  • In exceptional cases where an unexpected shutdown occurs, there will remain:
    • the unsigned IGC file;
    • the signature file with the two most recent valid signatures.

To repair the IGC file, it is necessary to:

  • Retrieve the IGC file and its corresponding signature file (same name, with a .sig extension);

  • Identify in the signature file the signature associated with the highest line number; 

  • Delete all data in the IGC file after that line number;

  • Add the valid signature at the end of the remaining IGC data.

A tool available in the Configurator performs automatically these operations.

6. A tool to repair interrupted IGC files

In the Configurator, advanced mode provides access to the tool for repairing interrupted IGC files:

  1. Click three times on the Vector Vario Configurator title to activate advanced mode;
  2. In the horizontal bar, click the tools icon ;
  3. Import the .igc and .sig files with the same name;
  4. Download the IGC file automatically repaired by the tool.

This tool does not verify the file’s validity; this operation is always performed by XContest.

7. Concerning the Vector Vario Pro

The Vector Vario Pro records data in a CSV file. An authentication system similar to the one used for IGC files is employed, except that the final signature is placed on the first line of the file. In case of an unexpected stop, all data after the last authenticated line must be deleted, and the signature on the first line replaced.

In the Configurator, the same tool used for repairing interrupted IGC files can perform this operation automatically without risk of error.

Contact us if it is necessary to certify the authenticity of the recorded data.

Conclusion – A black box ddapted for free flight

Without claiming the robustness and reliability of a commercial aircraft flight recorder, the Vector Vario implements a backup and signature strategy that allows:

  • Complete data recorded up to the last second ;
  • A signature always present and recoverable;
  • Compatibility with XContest ;
  • Data usable foradvanced analysis of flight and atmospheric conditions.

All of this in a lightweight, discreet instrument perfectly suited to free-flight activities.

Some measurements are only reliable if the Vector Vario is correctly oriented, and for paragliders, mounted on a normally tensioned riser. Outside of these conditions, parameters such as attitude or relative wind should be interpreted with caution. For incident or accident analyses, the most relevant data are usually those immediately preceding the event.

The black box system detailed on this page is available on the Vector Vario starting from version v1.32b released on 02/12/2025