NORMAL AERODROME OPERATING MINIMA – is applicable for all Scheduled or Non Scheduled Domestic and International Operators operating in India, who have filed and have received approval to operate with the normal Aerodrome Operating Minima.
RESTRICTED AERODROME OPERATING MINIMA – is applicable for all Scheduled or Non Scheduled Domestic and International Operators operating in India, who have either not filed or have not received approval to operate with the normal Aerodrome Operating Minima.
The Restricted Operating Minima is usually higher than Normal Operating Minima. The Standard rule that is followed to increase the Restricted Aerodrome Operating Minima above Standard
Operating Minima is as follows-
For Precision Approaches the Decision Height is increased by 100 feet for Category ‘A’ and ‘B’ A/c and by 50 feet for Category ‘C’ and ‘D’ A/c.
For Non Precision Approaches the Minimum Descent Height is increased by 100 feet for all Categories of the A/c.
STANDARD TAKE OFF MINIMA – is used at some Airfields, where the Take Off minima can be set to a lower value than the Landing minima. This is done when there is an alternate Runway available in the vicinity of the airfield with a published instrument approach procedure, where the A/c can divert to if it is required to make an emergency landing.
Whenever both Runway Visual Range and Visibility are available, the RVR will be the criteria for the Landing,
RVR is issued only when the visibility falls below 1500 meters.
RVR is measured at a height of 16 feet.
For landing purposes, the landing minimas are as follows-
If visibility is reported as 3000 meters, a 10 % reduction can be made to this visibility for the landing purposes.
Example- visibility reported as 3000 meters.
10 % of 3000 =300 meters, 3000-300 =2700 meters.
A/c can land with the pilot’s minima of 2700 meters.
Note – Remember only the reported visibility can be reduced by the above stated formula, the minimum visibility required by the company to land can not be increased by the 10% value or any such formulas