2.1.1   Units Of Measurement

The ICAO Table 3-4 of Annex 5 - Units of measurement to be used in the air and ground operations - has been selected for general use by all aeronautical and aircraft stations engaged in operations within Lisboa and Santa Maria FIRs.

The referred Table is also used in the AIP, VFR Manual and in NOTAM.

2.1.2   Time system

Coordinated Universal Time (UTC) is used in the air traffic and communications services and in documents published by the Aeronautical Information Service, unless otherwise indicated.

In reporting time, the nearest full minute is used, e.g., 12h 40min and 40s is reported 1241.

Time checks to aircraft are accurate within 5 sec.

The Winter Time in Portugal (Mainland) corresponds to UTC. In Madeira corresponds to (UTC) and in Açores corresponds to UTC minus 1 hour (UTC-1).

The Summer Time in Portugal (Mainland) corresponds to UTC plus one hour (UTC+1). In Madeira corresponds to UTC plus 1 hour (UTC + 1) and in Açores to UTC.

Times applicable during summer period are given in brackets.

Seasonal periods:

Winter From the last Sunday of October until the Saturday before the last Sunday of March.

Summer From the last Sunday of March until the Saturday before the last Sunday of October.

2.1.3   Geodetic reference datum

All published geographical coordinates indicating latitude and longitude are expressed in terms of the World Geodetic System — 1984 (WGS-84) geodetic reference datum.

Coordinates published with an asterisk (*) are transformed into WGS84 coordinates but whose accuracy does not meet the requirements in Annex 11, Appendix 5 and Annex 14, Appendix 5.

2.1.4   Aircraft nationality and registration marks

The nationality mark for aircraft registered in Portugal is the letters CS.

The nationality mark is followed by a hyphen and a registration mark consisting of 3 letters, e.g., CS-ADC.

2.1.5   Public holidays