1.

Units of measurement

1.1.

The table of units of measurement shown below will be used by aeronautical stations within Indian FIRs for air-ground operations

2.

Temporal Reference System

2.1

Gregorian calendar is used and Time periods published in AIS products are in Co-ordinated

Universal Time (UTC) except where otherwise stated. Reporting of time is expressed to the

nearest minute. E.g. 12:04:35 is reported as1205. Local time is 05:30 hours ahead of UTC

2.2

Daylight saving hours are not employed.

3.

Horizontal Reference system

3.1.

Name/designation of reference system

3.1.1.

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

3.2

Identification and parameters of the projection: Universal Transverse Mercator (UTM) projection is used.

3.3

Identification of the ellipsoid used: In India Geodetic Reference system-1980 (GRS-80) ellipsoid is used.

3.4

Identification of the datum used: In India International Terrestrial Reference Frame 2008 (ITRF 2008) is used.

3.5.

Area of application:

3.5.1.

Area of application for the published geographical coordinates coincides with the area of responsibility of the Aeronautical Information Service, i.e. the entire territory of India as well as the airspace over the high seas encompassed by the Chennai, Kolkata & Mumbai Flight Information Regions in accordance with the Regional Air Navigation Agreement.

3.6

An explanation, if applicable, of the asterisk used to identify those coordinates that do not meet Annex 11 and Annex 14 accuracy requirements: An asterisk (*) will be used to identify those published geographical coordinates which have been transformed into WGS-84 coordinates but whose accuracy of original field work does not meet the accuracy requirements in Annex 11, Chapter 2 and Annex 14, Volumes I and II, Chapter 2.

4.

Vertical reference system

Name/designation of reference system used: In India, AMSL is used in which Indian Mean Sea Level (IMSL) derived from nine-stations located along Indian subcontinent is used as a reference datum and wherever Earth Gravitational Model-2008 (EGM08) & Earth Gravitational Model-1996 (EGM96) are used, it is specifically mentioned.

5.

Aircraft nationality and registration marks

5.1.

The nationality mark for aircraft registered in India is the letter “VT” for civil aircraft and “VU” for Air-Force aircraft. The nationality mark is followed by a hyphen and a registration mark consisting of 3 letters e.g. VT-EPC or VU-AWB. The nationality mark for unmanned aircraft registered in India is U followed by 6 Alpha-Numeric characters, i.e., between 0 and 9 or A and Z, e.g., UB67DFC.

6.

Public holidays

6.1.

The following three national holidays are fixed and observed every year:

6.1.1.

Republic Day

26th January

6.1.2.

Independence Day

15th August

6.1.3.

Mahatma Gandhi’s Birthday

2nd October

6.2.

Government holidays for the year 2023 2024 are as follows: