N. Jeykumaran asked: What is the horizontal and vertical extent of the Indian air space? What is India's strategy to secure its air space?

Kishore Kumar Khera replies: Horizontally, the Indian air space is bound by the territory including territorial waters of the Union of India. Vertically, there are no defined limits. Owing to reduced air density with an increase in altitude, there are rarely any aircraft operations beyond 20 kilometres above mean sea level. Technically, Kármán line, at 100 kilometres above mean sea level (the highest altitude at which orbital speed provides sufficient aerodynamic lift to fly in a straight line for a typical aircraft), is considered inner boundary of outer space. However, there is no international legal definition of the demarcation between a country's air space and outer space.

The Indian Air Force (IAF) is the sole designated agency for the defence of Indian air space. The strategy to defend the Indian air space is based on surveillance, entry control and punitive action. Accordingly, approaches to the Indian air space are continuously monitored with the use of surface-based radars and augmented, on as required basis, with aerial platforms like Airborne Warning and Control System (AWACS) and Airborne Early Warning and Control (AEW&C) Aircraft. Incoming aircraft need to obtain prior clearance to enter Indian air space and the entry points are predefined. A tactical action is initiated in case of any deviation from the approved path by an incoming aircraft or approach to Indian air space without clearance. Armed fighter aircraft of IAF are always on standby to intercept and deal with an intruder. Intruding aircraft is forced to land at a suitable airfield for further investigations. In May 2019, an An12 aircraft that took off from Karachi and deviated from its path, and did not enter Indian air space from the designated point, was forced to land at Jaipur for further investigations. In case the orders by the interceptor are not followed, the intruder is warned prior to being shot. An Atlantique aircraft of the Pakistan Navy in 1999 and an F16 of the Pakistan Air Force in 2019 were shot down for violation of the Indian air space.

Posted on June 04, 2019