Good day bob
Why would that AIREP be a compulsory position report? It doesn’t tally from the ERC and the text book page. Shouldn’t an AIREP is a pilot report who will report if he encounter special significant weather conditions?
Cheers
The triangle with a square around it found on ERCs, indicates a position at which DESIGNATED aircraft are required to transmit environmental weather information along with a routine position report. This allows the Met people to update upper-level weather data as required. It is unlikely that a general aviation aircraft will be a designated aircraft for that purpose.
General aviation aircraft are requested to transmit a 'SHORT AIREP whenever significant weather is encountered that is not already mentioned in existing forecasts.
See AIP GEN para 5.3.4 and para 11.2 and para 11.3.1
