http://cities.expressindia.com/fullstory.php?newsid=213037
Visibility meters fail in fog fight
 
The haze-day 2: 22 flights delayed, DGCA says pilots trained on CAT-III to get take-off priority 
 
RAGHVENDRA RAO
 
NEW DELHI, DECEMBER 13 For a good 80 minutes, authorities at the Indira Gandhi International Airport were clueless about the Runway Visual Range (RVR) as meters installed at the mid and end-point of the main runway conked off.

Both the RVR meters, installed by the Meteorological Department to measure the visibility of light and surface markings, were hit by a snag at 6 am and could only be repaired by 7.20 am. This, when dense fog had reduced instrument visibility below 300 metres and general visibility below 100 metres between 5.30 am and 9 am today.

 
 
"Out of the three RVR meters installed ... the ones at mid-point and point 10 suffered from a mechanical problem. But we got them repaired promptly," R.K Jenamani, Met Department's Director In-charge at IGI said.

As many as 22 flights were delayed and only 36 flights could be operated during the LVP imposed between 5.10 am and 9.24 am. While one flight each to Srinagar and Bangalore was cancelled, two flights to Mumbai, including a Cargo plane, were diverted.

Meanwhile, the Directorate General of Civil Aviation (DGCA) today issued additional guidelines to deal with situation at IGI Airport. "Airlines which have CAT III compliant aircraft and crew shall get priority in sequencing and take-off," Director General Civil Aviation Kanu Gohain said. DGCA has instructed that pilots, while requesting for start up, shall intimate the ATC about whether the crew is CAT IIIA/B or CAT II qualified.

Only 126 pilots and 50 co-pilots, all belonging to national carriers Air India and Indian (Airlines), have been trained for low visibility operations using Instrument Landing System (ILS) CAT III B. Similarly, only 83 pilots and 24 pilots, again with the national carriers, are equipped to operate in CAT III A systems. While Jet Airways has 84 pilots and 76 co-pilots trained for CAT II operations, Air Sahara has 9 pilots and 4 co-pilots for the same.

CAT III B systems are used when RVR falls down to 50 metres and CAT III A systems are used when RVR falls down to 200 metres.

DGCA has said that low Visibility Procedures shall start from the moment the RVR drops to 800 meters or less.