For five days, the airport at Visakhapatnam has been shut to civilian traffic, leaving hundreds of passengers stranded. And this time it is not the airport’s bad layout — there’s annual flooding during the monsoons — that’s causing the problem: the shutdown is because the Navy-controlled airport lacks modern navigational facilities to guide civilian air traffic even in light smog conditions.

The airport handles 63 flights every week, operated by Indian Airlines, Kingfisher, Air Deccan and Air Sahara — all four have had to cancel flights. The only aircraft landing or taking off from Vizag are Navy helicopters.

Visibility at Vizag currently stands at 3,000-metres which is fine by standards at most airports in the country. But without a modern Instrument Landing System (ILS), Vizag requires a high minimum visibility level of 4,500-5,000-metres for landing aircraft. The hills that flank Vizag airport are also a hazard, contributing to the high visibility requirements, but they only represent part of the story.

Despite an increasing demand from civilian air traffic, the Vizag airport depends on virtually obsolete navigational aids that require near perfect visibility conditions. These systems include Conventional Omni-directional Radio, non-directional beacon and transponder-based distance measuring equipment to guide civilian traffic, all of which require very high “visibility minima”. All approaches and landings are, therefore, entirely visual, with no electronic navigational aids.

Comparable small civilian airports in the country, including Varanasi, Indore, Bhopal, Ranchi and Vadodara, have at least an ILS Cat-I navigational system which requires visibility of just 550-metres for landing. Delhi;s Indira Gandhi international airport has the much more sophisticated Cat-III B system, which requires visibility levels of just 200-metres or less. The Navy-controlled Dabolim airport in Goa also has the ILS Cat-I system.

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