How Track Validity Checks Work

Sometimes a pilot uploads the wrong file, such as a flight from another day or another site. It's an easy mistake to make and a hard one to spot: the file is valid IGC, it opens, and it looks like a flight.

Scoring alone won't catch it. Because tasks often run across UTC midnight, GlideComp works out start gates and deadlines from the flight being scored, not from a fixed date. So a tracklog from another day simply moves the whole task onto its own day and scores as if nothing were wrong.

FAI S7A §4.4.2 makes catching this the software's job: the points that verify a flight must have "occurred at reasonable times (e.g. on the day in question)".

Both checks ask one question: is this file this flight? Both use margins wide enough that no honest track comes near them.

A track that fails either check is left out of scoring, and out of the comp and task analysis, where its clock and its air would skew the day's statistics for everyone else.

These flags describe the flying, not the file. Each can also fire on a genuine flight, so GlideComp shows them for a person to judge. They never change a score.

• Never left the take-off cylinder. This is what a pilot who launches and sinks straight back down looks like, and they rightly get the minimum distance. It is also what a recorder left running on launch looks like.
• No sign of flight. There is no sustained climb (1.5 m/s for two minutes) and no sustained glide (90 seconds of descent at 0.8 m/s, never slower than 4 m/s over the ground, and roughly straight). This catches a vario that recorded the drive up to launch, which speed alone can't, because a retrieve vehicle is faster than a paraglider.
• Impossible speed. Ground speed stays above about 119 km/h for paragliders, or 162 km/h for hang gliders, for a full minute, tailwind included. The one-minute window filters out GPS jitter. This flag looks for something that isn't a glider.

A pilot who launches and lands short still gets the minimum distance, usually 5 km. That doesn't change: bad luck on a short flight is still a flight.

A withheld tracklog is different, because it isn't evidence that the pilot flew this task. Those pilots stay in the scores, placed last with zero points and the reasons beside their name. GlideComp never removes them.

No other pilot's score moves. The withheld pilot is left out of the launch-validity count ( S7F §10.1 ) rather than counted as having flown, so a wrong verdict can only ever cost that one pilot.

Under S7A §4.4.6, rejecting a tracklog is the organiser's call, not the software's. A scorekeeper can accept a flagged tracklog in one step. It is then scored normally, its findings stay visible, and the competition's public audit log records the decision.

If your track was withheld, upload the right file. If the file you uploaded is the right one, talk to the scorekeeper.

Wrongly zeroing a pilot is worse than letting a bad file through, so the thresholds are set from real competition data.

Across 4,762 archived tracks, the typical flight passes within 70 m of a turnpoint. The furthest any honest track stayed from every turnpoint was 45 km. The 100 km threshold is more than twice that.

The one-day grace comes from the same data. In one archived task, three of eighty pilots had recorders stamped a day late. All three flew the task and were scored normally in the published results; one finished fourth, in goal. A rule that rejected a one-day offset would have given that pilot zero.

Across all 5,112 tracks GlideComp holds, the checks withhold exactly one: a New Zealand flight submitted to a Victorian task ten days later.

When a check fires, the pilot's report card names it, shows the numbers behind it, and says what to do next. The scores table also labels a withheld track, so a zero never looks like a glitch.

It's the same rule as track data cleaning: everything GlideComp did on the way to a score must be visible.