service availability index based on the number of airports with EGNOS-based approach procedures with an operational status versus the total number of airports with EGNOS-based approach procedures;
innéacs infhaighteachta seirbhíse bunaithe ar líon na n-aerfort a bhfuil nósanna imeachta ascnaimh acu atá bunaithe ar EGNOS agus a bhfuil stádas oibríochtúil acu i gcoinne líon iomlán na n-aerfort a bhfuil nósanna imeachta ascnaimh acu atá bunaithe ar EGNOS;