PATNA, June 14 -- The Airports Authority of India (AAI) has recently sounded out the Bihar government that Patna airport is unsafe for air operation given its short runway length and operational constraints on both sides of Runway 25 and Runway 07, said officials. While there are trees of the Sanjay Gandhi Botanical Park and the secretariat clock tower on Runway 25, the overhead electricity traction line of the railways on Runway 07 pose obstructions to any incoming aircraft, said officials. The Air India plane crash in Ahmedabad on Thursday has again brought into focus how unsafe the Jayprakash Narayan International (JPNI) airport in Patna is. The AAI recently wrote twice in the previous two months of April and May to the Bihar government, highlighting the unsafe operations at the Patna airport. It has, in fact, been persistently pursuing since 2012 with the Bihar government for additional land to extend the runway length from the existing 2072 metres to at least 2500 metres, In its last letter to the Patna district magistrate in May, before the arrival of Prime Minister Narendra Modi to Patna on May 29, the AAI while mentioning about unsafe air operations at Patna airport, requested not only for cutting of trees at the adjoining zoo, but also for providing 500 metres of additional land towards the botanical park and trimming by 17.5 metres the height of the 56 metres (184 feet) tall secretariat clock tower, as per the Bihar tourism website. However, barring the occasional pruning of trees, nothing tangible has been done on ground from the Bihar government side, said officials. The last obstruction limitation assessment survey (OLAS) to identify and assess obstacles that could pose a safety risk to aircraft operations around an airport, undertaken by the AAI in 2022-23, had pointed to around 100 obstacles, including trees, the clock tower atop the old pre-Independence secretariat building, mobile towers and apartments beyond the permissible height around the Patna airport. Technical experts said the glide angle of aircraft, which is the angle between its flight path and the ground (runway) when an aircraft is descending to land, is steeper at 3.15 degrees at the Patna airport, as compared to the normal 3 degree. A smaller glide angle indicates a more efficient glide, meaning the aircraft can travel a greater distance for a given altitude loss. Given the 3.15 degree glide slope an approaching aircraft has to maintain, the total distance available (TDA) for landing is lesser than the existing runway length of 2072 metres because of the tall trees and clock tower and the overhead traction lines around the Patna airport, said officials. Aviation experts said that for a category C aircraft like the Boeing 737 or the Airbus 320, which operate at the Patna airport, the ideal minimum runway length should be 2500 metres. Given that making available additional land for extending runway length, cutting trees in the adjoining biological park, a protected forest area, or trimming the height of the clock tower atop the state's secretariat came under the Bihar government, the ball for ensuring safe air operations at Patna airport, is clearly in the state government's court, said officials. An Alliance Air Boeing 737-2A8 flight (CD 7412) crashed in Patna on July 17, 2000, killing 55 people on board the aircraft and five on ground. The incident happened around 7.30am at Patna's Gardanibagh area, barely 2km from the runway of the JPNI airport, when the aircraft from Kolkata to Patna enroute to Delhi via Lucknow was on its approach to land. The twitterati, meanwhile, called for immediate extension of Patna airport runway in light of the Ahmedabad air crash on Thursday. Users on X said, "Shiny terminals won't take away the risks associated with short runway at Patna airport." The PM inaugurated the new integrated terminal building of Patna airport, built at a cost of Rs 1200 crore, on May 29, and it was made operational on June 3. However, nothing has been done to improve its operational safety by increasing its runway length. Bihar's additional chief secretary cabinet secretariat, S. Siddharth, did not respond to HT's calls or text messages on his cellphone on Friday. Efforts to contact AAI chairman Vipin Kumar, a Bihar cadre IAS officer, proved futile as he did not respond to this reporter's calls, text message or email....