Much awaited Instrument Landing System (ILS) has been commissioned at Hubballi Airport. Dharwad MP Pralhad Joshi shared the news in a tweet and thanked Minister of Civil Aviation Hardeep Singh Puri. He also requested the minister to increase the frequency of Hubballi to Hyderabad flight.
As of now, Hubballi Airport is using DVOR (Doppler Very High Frequency Omni Range) to control Approach/Departure procedures. DVOR is a landing aid that is used to determine the flight Position and Direction in relation to their destination.
There was a demand to install ILS at Hubballi Airport owing to flight diversions and delays caused by bad weather including Heavy rain and Fog. ILS guides the pilots to land the aircraft safely even when the visibility is low.
In March 2015, a Spicejet aircraft (Bombardier Dash8 Q400) carrying 75 passengers has skidded off the runway due to bad weather. One is the reason attributed to the mishap was the lack of Instrument Landing System (ILS).
What is ILS? How does it work?
Instrument Landing System (ILS) transmits two signals from Airport to the flight.
- Localizer – It helps to keep the aircraft in centerline which means aligning the flight to the Runway Centerline (Lateral guidance).
- Glideslope – It helps the aircraft to maintain the correct descent profile (exact descent angle to be maintained to reach runway) the Vertical guidance.
When the aircraft captures both Localizer and Glideslope, they can continue their approach even when visibility is low (Fog or Rainy conditions). The approach is continued till Minimum Decision Height (DH). Once DH is reached pilots should have the runway in sight or else they will go around and wait until visibility improves.
Depending on DH, ILS landing is classified into different categories like Cat I, Cat II, Cat III-A, Cat III-B, and Cat III-C. Hubballi Airport is getting Cat I ILS. Decision height for Cat I ILS is not lower than 60m (200ft).