Helicopter Operations and Night Capability

IN INDIAN CONTEXT

The helicopter is probably the most versatile instrument ever invented by man. It approaches closer than any other to fulfilment of mankind’s ancient dreams of the flying horse and the magic carpet.

– Igor Ivanovitch Sikorsky

CHAPTER – I

INTRODUCTION

Background

1. After having flown the fixed wing aircraft successfully in 1903, man turned his attention towards the more complex and challenging problems of flying a rotary wing. The visionaries had long since prophesied the possibility of a vehicle that would takeoff vertically before moving forwards. The recorded evidence of this idea was found in the Chinese books as early as 400 BC, but it was probably only around 1490, when Leonardo da Vinci came up with his sketches of a similar vehicle, that the concept of helicopters actually advanced. Despite this, the first free flight was performed only in November 1907. Unlike the airplane, a helicopter is an aircraft with rotary wings. The capability to hover for long durations allows the helicopter to accomplish tasks unachievable by other means. In addition, the versatility and ease of operation, compared to a fixed wing aircraft make helicopters an excellent choice for all kinds of operations, by day and especially by night.

Evolution of Helicopter

2. The earliest mentions of a vertical flight have been in a Chinese book written in 4th century BC, referred to as Pao Phu Tau[1]. Someone asked the master about the principles of mounting to dangerous heights and travelling into the vast inane. The Master said, “Some have made flying cars with wood from the inner part of the jujube tree, using ox-leather [straps] fastened to returning blades so as to set the machine in motion”[2]. However, it was in 1490, when Leonardo da Vinci had the imagination to design a machine made of wood and starched linen, called the ‘helical screw’. This machine, operated by a spring mechanism, was supposed to literally screw itself vertically into the air. This machine, shown in Fig. 1, was the origin of the word helicopter. The word is a combination of the Greek words, ‘Helix’ meaning spiral and ‘Pteron’ meaning wing[3]. Thereafter, in July 1754, Mikhail Lomonosov demonstrated a small coaxial rotor for lifting meteorological instruments. Christian de Launoy, and his mechanic, Bienvenu, made a model with a pair of counter-rotating rotors, using turkey’s flight feathers as rotor blades, in 1784.

3. Between the Fifteenth and Twentieth Centuries, adequate machinery needed to produce helicopters, like turbine engines and rotors, was not yet made possible by assembly lines, but as the Industrial Revolution prompted factories and technology accelerated, the helicopter evolved. One of the first breakthroughs in helicopter advancement was by George Cayley who produced a converti-plane in 1843. A man named Bourne flew the helicopter-like aircraft a year later. Spring-like contraptions inside, apparently powered this model. All helicopter models at this time lacked suitable power to achieve flight and were both bulky and heavy[4]. In 1877, Enrico Forlanini’s unmanned helicopter, powered by a steam engine stayed at a height of 13 m for 20 secs after a vertical takeoff. However, Breguet-Richet‘s Gyroplane No. 1 achieved the first successful vertical flight, in September 1907. Since this machine did not have any control or steering devices of its own, this could not take the credit for the first helicopter to make a truly free flight. Paul Cornu claimed this recognition in November 1907, when he flew his ‘Flying Bicycle’ at a height of 0.3 m for 20 secs.

4. During the World War I in 1917, the engineers of Hungarian Ganz Company designed a radical motorized flying machine to replace the dangerous hydrogen-filled balloons, then being used to observe enemy positions. This aircraft flew to a height of over 50 m. 120 hp engines and two massive wooden propellers turning in opposite directions supported it. It was intended to lift a pilot, an observer, a machine gun and fuel for an hour’s flight. Because of great success and curious design, many specialists consider it as the world’s first real helicopter[5]. The quality and quantity of production materials increased, and great improvements were made in the field of engine technology in many parts of the world including Europe and the United States. An aircraft model for military advancement was needed for more versatile and precise war tactics. With better technology and more need, the next step in helicopter advancement would soon come.

5. Meanwhile, Juan de la Cierva was developing the first practical rotorcraft in Spain. In 1923, the aircraft that would become the basis for the modern helicopter rotor began to take shape in the form of an autogyro. Cierva had discovered aerodynamic and structural deficiencies in his early designs that could cause his autogyros to flip over after takeoff. The flapping hinges that Cierva designed for the C.4 allowed the rotor to develop lift equally on the left and right halves of the rotor disk. A crash in 1927, led to the development of a drag hinge to relieve further stress on the rotor from its flapping motion. These two developments allowed for a stable rotor system, not only in a hover, but in forward flight. Albert Gillis von Baumhauer, a Dutch aeronautical engineer, began studying rotorcraft design in 1923. His first prototype “flew” (“hopped” and hovered in reality) on 24 September 1925, with Dutch Army-Air arm Captain Floris Albert van Heijst at the controls. The controls that Captain Heijst used were Von Baumhauer’s inventions, the cyclic and collective. Patents were granted to Baumhauer for his cyclic and collective controls by the British ministry of aviation on 31 January 1927. At the same time, Boris N. Yuriev and Alexei M. Cheremukhin constructed and flew a single rotor helicopter that had an open tubing framework and utilized two anti-torque rotors, one each at tail and nose. Another Russian, Nicolas Florine, built the first twin tandem rotor machine to perform a free flight, in 1933. The Bréguet-Dorand Gyroplane Laboratoire was built in 1933. After many ground tests and an accident, it first took flight on 26 June 1935. Within a short time, the aircraft was setting records with pilot Maurice Claisse at the controls. On 14 December 1935, he set a record for closed-circuit flight with a 500-meter (1,600 ft) diameter. The next year, on 26 September 1936, Claisse set a height record of 158 meters (520 ft). And, finally, on 24 November 1936, he set a flight duration record of one hour, two minutes and 5 seconds over a 44 kilometre (27 mi) closed circuit at 44.7 kilometres per hour (27.8 mph). The aircraft was destroyed in 1943 by an Allied airstrike at Villacoublay airport. Despite the success of the Gyroplane Laboratoire, the German Focke-Wulf Fw 61, first flown in 1936, would eclipse its accomplishments. The Fw 61 broke all of the helicopter world records in 1937, demonstrating a flight envelope that had only previously been achieved by the autogyro. Nazi Germany would use helicopters in small numbers during World War II for observation, transport, and medical evacuation. The Flettner Fl 282 Kolibri synchropter was used in the Mediterranean Sea, while the Focke Achgelis Fa 223 Drache was used in Europe. Extensive bombing by the Allied forces prevented Germany from producing any helicopters in large quantities during the war.

6. In the United States, Igor Sikorsky built the VS-300, a single rotor design with a smaller rotor mounted vertically on the tail boom to counter the torque produced by the main rotor. Developed from this design, the R-4 became the first mass produced helicopter. This was also the only allied helicopter to see service in the World War II. Sikorsky produced over 400 helicopters of R-4, R-5 and R-6 types before the end of the war. Meanwhile, Bell Aircraft built the Model 30, which later developed into Bell 47, which became the first certified helicopter for civilian use and remained the most popular model for nearly three decades.

7. In 1951, Charles Kaman modified his K-225 helicopter with the turbo-shaft engine. This was a major development in terms of reducing weight penalty. On 11 December 1951, this became the first turbine powered helicopter, followed by Navy HTK-1 to be the first twin-turbine helicopter, in 1954. However, Alouette II was the first helicopter produced with a turbine engine[6]. More development were seen during the 1960s and 70s due to the Vietnam War. These advancements were fuelled by the military’s requirement for advanced helicopters for use as gunships, missile-launching platforms and for the rescue of the wounded troops. The Bell 209 Cobra was one of the helicopters produced at that time. Thereafter, with further advancement in technology, came the era of ‘Tiltrotors’. McDonnell produced their Tiltrotor UAV and Bell/Boeing produced the model 609, the world’s first commercial Tiltrotor[7]. Helicopters have continued to develop with the advancing technology and concepts like ‘NOTAR’, contra-rotating rotors, etc., have come into being. The helicopters have also found employment in nearly all walks of life and will continue to develop and find more areas of usability in the future. Nevertheless, for India the helicopter age started in the mid 1950s when a couple of Sikorsky helicopters flew in the Indian skies for the first time. The initial build-up was slow. The war with China in 1962 gave the necessary impetus to the chopper fleet in the armed forces. Since then there is no looking back[8].

CHAPTER – II

METHODOLOGY

‘When once you have tasted flight, you will forever walk the earth with your eyes turned skywards, for there you have been, and there you will always long to return”.

– Leonardo da Vinci

Statement of the Problem

1. To identify and study the roles and challenges for night operations by helicopters and to suggest measures to overcome these, in Indian context.

Hypothesis

2. Helicopters are going to be employed in greater numbers all over the world and India is no exception. Night helicopter operations will become a necessity due to the utilization of these machines in greater numbers as well as the future trends. Thus, India needs to improve the infrastructure and the support services to optimally utilise these flying machines by ensuring their unhindered operations by night.

Justification for the Study

3. The year 2008 had been declared as the year of the Helicopter, in India. The incredibly complex flying machine has come a long way and is now whirring at India’s doorstep like never before, both in the civil and military sectors. That is why the third International Seminar Heli Power India 2008 turned into a resounding success after Heli Power India 2006[9]. In addition, in August 2009, U.S. Trade and Development Agency (USTDA) awarded a grant to the Directorate General of Civil Aviation (DGCA), in India, to help update regulations and practices governing helicopter operations. The USTDA grant, to be carried out under the auspices of the U.S.-India Aviation Cooperation Program (ACP), will aid in the growth and development of India’s civil aviation sector by fostering increases in the volume of helicopter operations in the expanding Indian market[10]. Even though the growth of civil helicopter industry has stalled a bit in the world scenario, there is optimism in its growth in India. In a presentation at HELI-EXPO 2006, Air Vice Marshal Sridharan said, “India is truly a helicopter country on account of its diverse topography”[11]. This was because of the interlacing rivers and numerous hill ranges that impede the development of rail/road network. Helicopters are routinely employed by civil administration to support Government operations to connect to population centres in most of north India. Also since India is prone to natural disasters, wherein helicopters are utilised in a big way for relief operations, the need for, and thus the numbers of helicopters in operations is going to steadily increase.

4. The helicopter strength has not increased greatly in the defence services, though there are plans to upgrade the existing fleet as well as procure new helicopters in the near future. This will be mandatory keeping the internal security scenario in mind post 26/11 incident at Mumbai. Along with the increase in the number of helicopters, the changing scenario is laying more emphasis on night operations, throughout the world. Therefore, it is necessary to evaluate our capabilities to be able to undertake unhindered helicopter operations by night.

Scope

5. This study concentrates on bringing out the present and future roles envisaged for helicopter night operations, both civil and military, in Indian context. The paper is also intended to analyse the challenges to these operations, not considering the financial implications, and make some recommendations to enhance helicopter operations in India.

Method of Data Collection

6. The data/information for preparing this dissertation has been collected through books, periodicals, aviation magazines, journals and articles available at the Defence Services Staff College Library, Wellington. Handouts issued by the College and various papers presented on helicopters have been referred to. Due to the paucity of literature in the library, articles, publications, papers by professionals available on internet have been extensively used. Many aspects have been discussed with officers from the helicopter stream of all three services. Bibliography of the various sources has been appended to this paper.

Organisation of the Dissertation

7. The paper has been organised into chapters. It is proposed to study the subject in the following manner:-

(a) Chapter – I. Introduction

(b) Chapter – II. Methodology

(c) Chapter – III. Characteristics of a Helicopter

(d) Chapter – IV. Helicopter Operations in India

(e) Chapter – V. Helicopter Night Operations: Civil

(f) Chapter – VI. Helicopter Night Operations: Military

(g) Chapter – VII. Requirements for Night Operations

(h) Chapter – VIII. Challenges in Night Operations

(i) Chapter – IX. Recommendations

(j) Chapter – X. Conclusion

CHAPTER – III

CHARACTERISTICS OF A HELICOPTER

“Helicopters are really a bunch of parts flying in relatively close formation; all rotating around a different axis. Things work well until one of the parts breaks formation”.

– Anonymous

1. Unlike an airplane which uses the engine thrust for forward propulsion and the fixed aerofoil sections (wings) for the lift, a helicopter uses a set of rotating aerofoil sections (rotors) for both the lift as well as the directional motion. The engine power is primarily used for rotating the main rotor. It also has an anti-torque system in the form of a vertical tail rotor/contra-rotating coaxial main rotor or in some types; called the ‘NOTAR’, the jet efflux from the main engine is used for this purpose. This method of lift generations bestows the helicopter with the ability:-

(a) To takeoff and land vertically

(b) To hover over any given point

(c) To move in any direction, i.e. forward, backward and sideways

(d) Turn through 360° over a given point.

2. At times the helicopter require a short air strip to be able to carry out Short Takeoff and Landing (STOL) instead of the Vertical Takeoff and Landing (VTOL) due to the power requirement for VTOL not being available. This would depend on the:-

(a) All Up Weight (AUW). More the AUW more will be the power required for VTOL.

(b) Winds. Like conventional aircraft, helicopters takeoff/land most efficiently, when pointed into wind. Stronger the head winds the more efficiently the machine behaves.

(c) Density Altitude (DA). This is a function of the prevailing temperature and the density at the operating altitude and this determines the performance of the helicopter. Lower the DA better is the performance and load carrying capacity of a helicopter.

Types of Helicopters

3. The helicopters are classified into various types based on their Maximum Takeoff Weight (MTOW), their role and their design[12]. Based on the MTOW they are classified as:-

(a) Type-I (Heavy) – Skycrane S-61, Chinook, Mi-26

(b) Type-II (Medium) – Bell 205

(c) Type-III (Light) – Jetranger / Md-500

4. Based on the role they are classified as:-

(a) Utility helicopter – Mi-8, Mi-17, UH-1 Huey

(b) Armed helicopter/Gunship – A utility helicopter with limited firepower

(c) Attack helicopter – Mi-25/35, AH-64 Apache

(d) Airborne Early Warning (AEW) helicopter – Kamov Ka-32

(e) Anti-Submarine Warfare (ASW) helicopter – Seaking

(f) Multi-mission and Rescue helicopters – Chetak, Cheetal

(g) Observation helicopters – OH-58 Kiowa, Gazelle

(h) Training helicopters – Robinson R22, Cheetah

(j) Skycrane helicopters – Sikorsky S-64

(k) Helitack helicopters – Bell 205

(l) MEDEVAC helicopters – Sikorsky S76-C+

(m) Unmanned helicopters – Sikorsky “Cypher II”, Bombardier CL-327 “Guardian”

5. Based on their construction, they are classified as:-

(a) Conventional (Single rotor and tail rotor combination) – Alouette III, HAL Dhruv

(b) NOTAR (No Tail Rotor) – MD Helicopters 520N, Aerotécnica AC-14

(c) Tandem rotor – CH-47 Chinook, Boeing Vertol 107-II

(d) Fenestron – Eurocopter EC120B, Aérospatiale Gazelle

(e) Tip jet rotor – McDonnell XV-1, Hughes XH-17

(f) Coaxial rotors – Kamov-32, Sikorsky S-69

(g) Synchropter – Flettner Fl 282 “Kolibri”, HH-43 Huskie

(h) Compound helicopter/Gyrodyne – McDonnell XV-1, Kamov Ka-22

(j) Tilt rotor – Bell/Boeing V-22 Osprey, Bell/Agusta BA 609

(k) X-wing – Sikorsky S-72 (only experimental)

Advantages over Fixed Wing

6. The major advantages of a helicopter over a conventional fixed wing aircraft are as follows:-

(a) Ubiquity. The ability of a helicopter to operate from any/every place, without the requirement of a prepared surface, is its biggest advantage. This is also the major factor which favours extensive night operations by a helicopter, as it does not require elaborate infrastructure for night operations.

(b) Flexibility. The helicopter is very flexible in terms of task performance. It can be converted from one role to another with minimal time, resources and effort. This characteristic aids in ease of operations by night wherein there would be constraints in terms of lighted space, etc.

(c) Vertical Envelopment. Helicopters can achieve and maintain vertical envelopment without the need for a linkup.

(d) Versatility. The helicopter’s ability to fly at all speed regimes (i.e. 0 to maximum) and at very low heights, permits the use of terrain masking to improve its survivability and thus its utilization in combat scenario. This property also propels the use of helicopter in various civilian applications like survey, meteorological observation, etc.

(e) Logistic Support. Due to the above-mentioned attributes, the helicopter is the ideal platform for speedy logistic support in confined/inaccessible areas both for military as well as civilian needs.

(f) Under Slung Load. Helicopters also have the advantage of carrying the cargo/payload either inside their fuselage or, if the size/shape of the cargo/payload so demands then, outside as an under slung load, with minimal penalty.

(g) Weather. Helicopters can be flown in weather conditions like poor visibility and precipitation which would not permit flight of an airplane, owing to their versatility. Availability of better onboard avionics has improved its all weather capability manifolds.

(h) Night Operations. Owing to its ubiquity, versatility and the capability to operate in marginal weather conditions, helicopters make an ideal choice for night operations.

Limitations

7. Helicopters do have certain disadvantages as well, in comparison to a fixed wing aircraft. Some of these are:-

(a) Limited Speed. Due to the characteristics of rotating rotor blades (tip speeds approaching 1 Mach) helicopters cannot travel faster than about 350 kmph[13]. These speeds are very low and unsafe in a combat area.

(b) Fuel Consumption. Helicopter consumes more fuel than a conventional aircraft in performing the same task.

(c) Limited Range. Helicopters being smaller, carry lesser fuel. This coupled with the higher fuel consumption have a severe limitation on the range of operations of helicopters.

(d) Payload. Helicopters have to strike a balance between the size and weight of the intended payload viz. their own design and manoeuvrability. The bigger the intended payload the bigger the helicopter and lesser is the manoeuvrability (applicable for both internal and under slung loads). Also, the payload capacity of the helicopter reduces more rapidly with increase in altitude, compared to an airplane.

(e) Maintenance. Maintenance is difficult due to large number of moving part[14].

(f) High Cost. Rotorcraft being complex cost many times more than conventional airplane of similar performance, both in procurement as well as in operations.

(g) Noise & Vibrations. Helicopters are inherently noisy and prone to vibrations due to the rotor dynamics. This is problem area for both civil as well as military employment of these machines.

(h) Limited Service Ceiling. In general, helicopters have a much lower service ceiling compared to an airplane. Additionally, most of the helicopters have an unpressurised cabin/passenger area, thereby forcing them to operate at much lower altitudes, due oxygen considerations.

(i) Vulnerability. Noise, low speed and limitations due load are the major contributors to military helicopters being vulnerable to enemy fire. Thus, the armour requirement for the helicopter depends on these factors.

CHAPTER – IV

HELICOPTER OPERATIONS IN INDIA

“Any Air Force that welcomes the onset of darkness…is well on its way to victory”

– Mark Hewish

Civil Helicopters

1. Though the history of helicopter dates back to 400 BC, for India the helicopter age started in the mid 1950s when a couple of Sikorsky helicopters flew in the Indian skies for the first time[15]. These helicopters were for the Indian Air Force. The first commercial helicopter flight was undertaken by Capt. R Captain in a Hiller UH 12B in Nov 53. Helicopters in both civil & military have been in service of the nation for over 59 years. From 1953 to 1986, the commercial use of helicopters in India was limited to small Aviation companies who were involved in communication and crop spraying roles. The formation of Helicopter Corporation of India by the Govt in 1986 (later named Pawan Hans Helicopters Limited) with a fleet of 42 helicopters provided the first boost to the Industry in the country. The growth rate has registered double digit only since 2004. Since then, until 2007, the growth of civil registered helicopters has been very modest, as shown in Fig 2[16].

2. Against a global average of one helicopter per half million people, in India the ratio is one helicopter for five million. The Rotary Wing Society of India (RWSI), the only society of its kind came into existence in 1998 and that too due single handed efforts of Air Vice Marshal (Retd) K Sridharan. Despite the late start, the prospects for growth in civil helicopter fleet are bright. The rapidly growing economy with activities spreading to remote, inaccessible areas, increased dependence on air travel and the ever widening search for energy reserves could propel growth in the next few years[17]. Realising the potential shown by civilian helicopter operations across the country, the civil aviation ministry is reportedly setting up a ‘Helicopter Mission’ to coordinate helicopter operations and deliberate on relevant issues[18].

Military Helicopters

3. The build up of military helicopters was slow and the impetus to the fleet actually came only after the 1962 war with China, although some helicopters did see action in that war itself, primarily in the casualty evacuation role. The earliest helicopter pilots in India were former Fighter and Transport pilots who for medical reasons or ‘service exigencies’ were moved to helicopter units. They were joined by some pilots of the Auxiliary Air Force. The first ‘true blood’ chopper pilots were commissioned with the 83rd Pilots Course in 1963. As no helicopter training facility existed in India, those flight cadets who were selected to fly choppers were sent to the UK or USSR for their initial conversion before returning home to join Mi-4 or Chetak units. Subsequently a Logistic Support Training Unit was set up in Allahabad for training helicopter pilots, and this was later converted to the Helicopter Training School, which is currently located at Fighter Training Wing in Hyderabad[19]. From this modest beginning the IAF has grown in strength and capability to now participate in international exercises as well as in UN peace keeping missions all over the world.

Helicopter Industry

4. Hindustan Aeronautics Limited (HAL) came into existence on 01 October 1964. The Company was formed by the merger of Hindustan Aircraft Limited with Aeronautics India Limited and Aircraft Manufacturing Depot, Kanpur. The Company traces its roots to the pioneering efforts of an industrialist with extraordinary vision, the late Seth Walchand Hirachand, who set up Hindustan Aircraft Limited at Bangalore in association with the erstwhile princely State of Mysore in December 1940. The Government of India became a shareholder in March 1941 and took over the Management in 1942. HAL’S involvement with rotary-winged aircraft dates back to June 1962 when, to meet the Indian Air Force’s requirement for light helicopters, the Government of India signed a licence agreement with M/s SUD-AVIATION (Presently M/s EUROCOPTER, France)[20].

5. The first helicopter type to be built at HAL Bangalore was the Alouette Ill, later named Chetak, with firm orders having been placed in January 1965, the “raw material” production phase beginning in 1969-70. The Alouette II, with the dynamics including power plant of the Alouette Ill was specifically developed to meet the Indian Army’s stringent requirement and was christened Lama by the French (and Cheetah by the Indians). First Cheetah manufactured from raw materials was delivered in 1976-77[21].

6. Over the next twenty years, HAL’s Helicopter Division produced hundreds of Chetak and Cheetah helicopters for the Indian Air Force, Navy, Army and Coast Guard as also for a number of civilian customers, including State Governments while a score or more were exported. This division has also produced the Dhruv helicopter (Advanced Light Helicopter-ALH) and its variants for the three services as well as for certain friendly foreign nations. It is currently pursuing the series production of the same and also developing the Indian Light Combat Helicopter (LCH)[22].

7. India’s attraction for helicopter makers is reaffirmed by strategic deals struck in the past year by key rotorcraft players. Sikorsky Aircraft has signed a Memorandum of Understanding (MoU) with a unit of Tata Group on the production of cabins for the S-92 helicopter and Eurocopter has expanded its manufacturing capability in India in collaboration with Mach Aero[23].

CHAPTER – V

HELICOPTER NIGHT OPERATIONS: CIVIL

Any idiot can get an airplane off the ground, but an aviator earns his keep by bringing it back anytime, anywhere, under any circumstances that man and God can dream up.

– Walter Cunningham

1. Helicopter is a unique and very versatile machine and can be deployed in variety of roles by modifying them even at a very short notice. The various civil operations that can be undertaken by helicopters in the night are discussed in the following paragraphs. The many other roles undertaken by helicopters like, the use of Sky crane, maintenance and repair of overhead high tension cables, etc. are not discussed here as these operations are likely to be undertaken in day only.

2. Helicopter Emergency Medical Service (HEMS). Helicopters are used as air ambulances for emergency medical assistance in situations when an ambulance cannot easily or quickly reach the scene. Helicopters are also used when a patient needs to be transported between medical facilities and air transportation is the most practical method for the safety of the patient. Air ambulance helicopters are equipped to provide medical treatment to a patient while in flight. The use of helicopters as an air ambulance is often referred to as MEDEVAC, and the service is known as Helicopter Emergency Medical Service (HEMS)[24], [25].

3. Disaster Management. Disaster relief and humanitarian operations have become an increasingly important part of missions undertaken by many air forces around the world. The very magnitude of natural disasters like the massive tsunami, earthquake in 2001 and the seasonal floods in country warrant concerted efforts by various agencies to cope with the widespread destruction caused. Inevitably the helicopter had yet again featured as the primary air asset in bringing relief to the victims in these areas, be it food supplies, medical evacuation or movement of rescue parties to the hard to reach stricken areas. Tactical transport helicopters were used in a variety of multi-tasked missions from various air force bases around the region. They provided a vital link in creating the bridge for movement of personnel and materials in areas with little or no accessibility. At times, these operations had to be delayed due to the inclement weather or the absence of night capability with the helicopter in use. These occurrences reiterate the need for the nation’s armed forces as well as civil agencies to maintain a modern and effective rotary winged element that is capable of responding to these situations, irrespective of day or night[26].

4. Airborne Law Enforcement. Police departments and other law enforcement agencies, in other nations, use helicopters to pursue suspects. Since helicopters can achieve a unique aerial view, they are often used in conjunction with police on the ground to report on suspects’ locations and movements. They are often mounted with lighting and heat-sensing equipment for night pursuits[27]. The same is likely to be inducted into our Police and other security agencies, in the future.

5. Electronic News Gathering. Helicopters, due to their versatility & ubiquity, have become a popular means of electronic news gathering. The helicopters come equipped with gyro stabilised zoom cameras mounted under the fuselage and all other associated electronic equipment onboard for a direct transmission on satellite television. They are also equipped with cameras and lights for night time operations. Though this is not yet proliferated to India, the time is not very far when we’ll see couple of these helicopters operating overhead, on a 24 x 7 basis.

6. Aerial Survey. Government and industries require various surveys like damp surveys, heat loss surveys, insulation integrity, water ingress, electrical distribution inspections, aerial mapping & GIS of cities, pipeline aerial surveys, landfill site surveys for detection of methane gas and leachate flows, animal censusing surveys, sub-surface heating pipe/wiring detection and mapping etc. For their planning and development processes. These can be easily carried out by suitable equipment mounted on a helicopter. The advantage being that since the helicopter travels at a much slower speed and at a lower height compared to an airplane; the sampling rate for each parameter would be that much higher