Guest Column | A Tall Order

The IAF has adapted well to latest technology for high altitude operations

AVM Manmohan BahadurAVM Manmohan Bahadur (retd)

It was just 18 years back that ‘Kargil’ happened — the first war in Indian history to be carried live into our bedrooms, thanks to the expansion of national television networks. The Indian Air Force (IAF) had named its operation as Operation Safed Sagar.

It brought forth operational challenges that no one had ever thought of, nay dreamt of, including by the manufacturers of weapon systems and associated equipment. The almost two-month long engagement, fought at dizzying heights of 16 to 17,000 feet Above Mean Sea Level (AMSL) by the Indian army, required the Indian Air Force (IAF) to deliver ordnance at targets associated at those altitudes – their weapon release points and altitudes can well be imagined!

This article discusses the peculiarities of conducting high altitude operations and how the IAF plans to conduct such missions. This analysis is especially important at this juncture as India and China have just been through a two-month eyeball to eyeball contest at the 14,000 ft Doklam area in Bhutan — whether more such tensions and skirmishes can be expected is a subject for another analysis.

The IAF’s operating environment is an aerodynamicist’s and weapon system designer’s delight as well as a nightmare; the same fixed wing or rotary wing aircraft is supposed to operate and deliver ordnance and/or cargo from sea level to 15,000+ feet AMSL altitude! This brings in three basic requirements. First, the requirements of the platform (on which the weapon is mounted), second, the issues that need to be factored-in by the aircrew while flying and lastly the combat support environment to operate flying platforms.

HAL Rudra

Platform Requirements

Ideally, an operator would like to have a platform that carries high payload at high speed and with high endurance. The platform should be able to carry out its missions by day and night and in adverse weather conditions.

Maintenance requirements should be low and it should be possible to service the platform in field conditions, and prepare it for missions with a minimal requirement of specialist tools and equipment. Such an aircraft does not exist! The reality of aircraft design and performance is far removed from this utopian wish; it gets tougher when one talks of operations at high altitude.

All other parameters being fixed, the performance of an airborne platform is a function of altitude and temperature - and hence air density. It is common knowledge that with increase in altitude and/or temperature the density of air reduces, thereby increasing the density altitude.

Aircraft performance depends majorly (among many other factors) on the prevalent density altitude; the higher the density altitude the more adverse is aircraft performance — this explains why every aircraft and major weapon system is tested in Jaisalmer during summers when the temperature is between 45-50 degrees C, and Leh in winters where the altitude is 11,000 ft and temperature drops to below -25 degrees C.

Added to that is the fact that aero-engine power reduces drastically with increase in altitude. Practically, due high costs of aircraft, most airborne platforms are multi-role so that they can be used optimally. Thus, an element of compromise comes in between load carrying capability and manoeuvring aerodynamic performance that is needed.

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