Our dear AAI (Airports Authority of India) has messed up the landing facilities at BIA and HIA:
"The new airports in Bangalore and Hyderabad are claimed to be ‘world class’. To achieve that title, several requirements have to be met. While the runway and the ground facilities of the two airports seem to be of the required standard, they fall short in an important area — rapid connectivity to the city. When one looks at the airports that get selected for the top slots worldwide, the connectivity infrastructure is initiated even when the airport design is in the conceptual stage.
The two airports also fail in a very important safety aspect. While the builders have done a good job as regards construction of the runway and other ancillaries, the Airports Authority of India has erred badly in the installation of the Instrument Landing System Glide Slope in both Bangalore and Hyderabad.
An aircraft coming in to land normally descends on a 3-degree glide slope. Yet , the AAI has installed the glide slope to an angle of 3.30 degree at one airport and 3.40 degrees in the other, forcing the aircraft to descend more steeply than it needs to, that is, at 900-1000 feet per minute. As the structural limit for the landing gear (or the wheels of the aircraft) is only 600 feet per minute, pilots have to shift from the high sink rate to a rate less than 600 feet per minute just before landing with a flare manoeuvre. Any delay, either due to a judgement error or fatigue, can result in a hard landing or a tail strike.
This Glide Slope angle is steeper than the limit of 3.25 degrees set for instrument landing systems Category II or III that are used in poor visibility conditions. By taking the easy option, the Bangalore and Hyderabad airports will allow landings only when the visibility conditions are more than 550 metres."
Forward this Blog entry