Nagpur: R. B. S. Narayan, a retired meteorologist from the India Meteorological Department (IMD), sheds light on the critical role of meteorological services in aviation safety. In his analysis, he explores the regulatory framework, ethical considerations, and social responsibilities associated with aviation operations. Highlighting the challenges faced by the sector, he emphasizes the need for accurate weather forecasting, stringent safety protocols, and a commitment to ethical decision-making to ensure secure and efficient air travel.

Introduction

Humans are social beings with an inherent tendency to explore new relationships, travel, and discover new horizons. Transportation has always been a crucial part of human civilization, enabling trade and fostering the growth of cultures. It facilitates the movement of people, animals, and goods through various modes, including air, rail, road, water, cable, pipelines, and space. Since ancient times, humans have utilized various means of transport such as bullock carts, horse carriages, rickshaws, bicycles, cars, buses, trucks, trains, airplanes, elevators, trolleys, trams, metros, boats, and even rockets to fulfill their travel needs.

Air Transport

Air travel has revolutionized transportation by making journeys faster and more comfortable. Today, we can fly through the skies and reach distant cities in a matter of hours. A flight covering over 1,000 kilometers takes just one to two hours, offering a smooth and fatigue-free journey. The development of aviation has significantly reduced travel time from months to mere hours, making the world feel like a small village. Due to its speed and ability to overcome geographical barriers, air transport has become the preferred mode of travel. Apart from passenger and cargo transport, air travel is crucial for national defense and emergency response. In remote areas such as the Himalayas, aviation plays a vital role in reaching destinations swiftly. Additionally, air transport is essential for the rapid delivery of mail. Given India’s vast and diverse geography, the importance of air transport is self-evident. Positioned as a bridge between Western countries and Southeast Asia, India holds a central place in global aviation.

Challenges in Air Transport

Despite being considered one of the safest modes of transportation, air travel can still be nerve-wracking, especially in adverse weather conditions. In good weather, a flight feels as comfortable as sitting in a chair on the ground, with only slight noise in the background. However, when the weather turns turbulent, flights can become distressing. Hundreds of airplanes encounter bad weather daily, and turbulence caused by storm clouds or sudden atmospheric changes can make passengers anxious. Pilots are trained to avoid extreme weather conditions and always consult meteorological services before flights. Therefore, when experiencing turbulence, passengers should remember that skilled pilots, advanced aircraft, and meteorological support ensure their safety. Meteorologists work tirelessly, like vigilant border security personnel, monitoring weather conditions 24/7 to provide crucial updates to pilots.

Among the major challenges in air transport, technical failures in aircraft can be mitigated using advanced engineering and high-quality equipment. Human errors can be reduced through comprehensive training and the deployment of experienced staff. The growing threat of terrorism can be controlled with well-trained security forces and advanced technology. However, weather-related disruptions remain beyond human control. Studies show that nearly 80-90% of aviation accidents occur due to adverse weather conditions. Since nature cannot be conquered, the best approach is to adapt air transport operations according to weather conditions. Conducting thorough weather forecasts and assessments before every departure and arrival is essential for ensuring flight safety.

History of Indian Civil Aviation

October 15, 1932, marked a historic milestone in Indian aviation when Tata Airlines (later Air India) conducted its first flight. By 2016, India celebrated 84 years of aviation history. Air transport in India began in 1911 with the world’s first airmail service between Allahabad and Naini. The Indian National Airways Company was established in 1933. In 1953, all aviation companies were nationalized and placed under two newly formed corporations. On August 24, 2007, Air India and Indian Airlines merged into a single entity named “Air India.” The International Airports Authority of India, in collaboration with private firms like GVK and GMR, manages major airports in Mumbai, Kolkata, Delhi, and Chennai. The National Airports Authority oversees 86 domestic airports and civil aviation operations at defense airstrips. The Ministry of Civil Aviation and the Directorate General of Civil Aviation (DGCA) are responsible for formulating policies and regulations, expanding civil aviation infrastructure, and ensuring safety standards. The Airports Authority of India (AAI) was established on April 1, 1995, through the merger of the International Airports Authority of India and the National Airports Authority. AAI is responsible for air traffic control, aviation communication services, and ensuring the safety and efficiency of air navigation in Indian airspace.

Objectives and Network of Aviation Meteorological Services

The Indian Meteorological Department (IMD) is the national authority for providing meteorological services to domestic and international aviation in accordance with guidelines from the World Meteorological Organization (WMO) and the International Civil Aviation Organization (ICAO). The primary goal of these services is to enhance aviation safety and navigation efficiency. This objective is achieved by providing essential weather information to operators, air traffic control (ATC), airfield management, and other relevant agencies.

Meteorological services are provided as per ICAO Annex 3, which outlines global aviation weather standards. In recent years, India’s aviation industry has witnessed significant growth with the entry of private airlines. Major domestic aviation players, including Air India, Jet Airways, IndiGo, Kingfisher Airlines, and GoAir, have intensified competition in the market.

Weather Elements That Pose a Threat to Aviation Services

The first modern aircraft was created by the Wright brothers. As children, Wilbur and Orville’s father, who served as a bishop at the United Brethren Church in Huntington, USA, gave them a toy helicopter. This inspired them to build a real flying machine. Finally, on December 17, 1903, they successfully tested their aircraft. During early tests, when the plane frequently crashed, the younger brother suggested, “We should fly early in the morning when the wind is calm.” The elder brother agreed, emphasizing that “calm wind” is necessary, while “crosswind or strong wind” would hinder the mission. The next morning, they flew the aircraft successfully, marking the beginning of “aviation meteorology.” The Wright brothers understood the importance of wind, visibility, and temperature in air transport—factors that continue to influence aviation today.

Wind Direction and Speed

Wind direction and speed, whether at the surface or higher altitudes, play a crucial role in aircraft operations. During takeoff and landing, a headwind (wind blowing against the aircraft) is essential to provide thrust for takeoff and braking action for landing. Similarly, at cruising altitudes, a tailwind (wind pushing the aircraft forward) is beneficial for fuel efficiency and reducing carbon emissions, which also helps in saving foreign exchange.

Visibility

For safe takeoff and landing, a pilot must have a clear view of the runway. However, visibility often reduces due to various factors, forcing aircraft to either circle in the air or divert to an alternate airport until conditions improve.

• Fog and Haze: These often reduce visibility, disrupting air traffic.

• Thunderstorms: These typically occur due to cumulonimbus clouds, which are the most dangerous for aviation. Thunderstorms reduce visibility, cause lightning and heavy rainfall, and generate strong surface winds. They are associated with low-pressure zones and convective clouds, making aircraft susceptible to updrafts and downdrafts, increasing the risk of accidents.

• Rain: During monsoon seasons or due to western disturbances, heavy rain reduces surface visibility.

• Dust Storms: These occur due to western disturbances or induced circulation in India, drastically reducing visibility. Due to low humidity, strong surface winds generate dust storms, which typically occur in the afternoon when cumulonimbus clouds develop.

• Hailstorms and Heavy Rainfall: These interfere with flight operations due to solid ice pellets or excessive rainfall.

• Snowfall: Powdery snow occurs in Jammu and Kashmir during winter due to western disturbances, affecting flights.

Air Turbulence

Turbulence, whether in clear air or caused by convective clouds, can be dangerous for aircraft.

Clouds

Various types of clouds affect aviation:

• Low-level clouds (e.g., stratus clouds): Reduce visibility.

• Mid-level clouds (e.g., cumulonimbus clouds): The most hazardous for aviation, causing reduced visibility, lightning, thunderstorms, and strong surface winds. These clouds are associated with low-pressure areas and convective activity, increasing accident risks.

Temperature

For optimal engine efficiency, low temperatures are essential. As temperature rises, air density decreases, forcing aircraft to reduce their load. Even a 1-degree Celsius increase in temperature requires a significant reduction in aircraft weight.

Air Pressure

According to Laplace’s formula, air pressure decreases with altitude. Aircraft use an altimeter to measure altitude based on this principle. Air pressure referenced to sea level is known as QNH, while pressure measured relative to station level is called QFE.

Aviation Weather Services Provided by the India Meteorological Department (IMD)

The India Meteorological Department (IMD), under the Ministry of Earth Sciences (MoES), Government of India, provides meteorological services for civil aviation. The Director General of Meteorology at IMD, located at Mausam Bhavan, Lodhi Road, New Delhi – 110003, oversees these services.

Aviation meteorological services are provided within the Chennai, Delhi, Kolkata, and Mumbai Flight Information Regions (FIRs). The system includes:

• 4 Meteorological Watch Offices (MWOs): Located at major international airports in Chennai, Kolkata, Mumbai, and Delhi, responsible for continuous weather monitoring. They issue SIGMETs (Significant Meteorological Charts) to warn about hazardous weather phenomena like thunderstorms, tropical cyclones, depressions, and volcanic ash.

• 18 Aerodrome Meteorological Offices (AMOs): These provide forecasts, warnings, and real-time observations for flights operating from their respective airports.

• 51 Aeronautical Meteorological Stations (AMSs): These supply real-time weather observations, supporting AMOs with forecast requirements.

Modern Weather Monitoring Systems

To ensure accurate weather monitoring, Indian airports have implemented:

• Runway Visual Range (RVR) Monitoring: Ensures continuous visibility measurement for safe operations.

• Automated Weather Observation Systems (AWOS) and Integrated Automated Meteorological Observing Systems (IAAMS): Provide real-time weather updates, particularly for runway conditions.

Fog Forecasting

During winter, critical fog prediction products are uploaded on IMD’s website. A dynamic-statistical model helps forecast changing visibility conditions at northern Indian airports.

Aviation Weather Forecast Formats

1. METAR (Meteorological Aerodrome Report)

• Issued every 30 minutes, providing real-time weather observations, including:

o Surface wind

o Visibility

o Current weather conditions

o Cloud cover

o Temperature and dew point

o Atmospheric pressure

• SPECI Reports: Issued whenever there are significant changes in weather conditions.

• TREND Forecasts: Brief two-hour forecasts attached to METARs.

2. TAF (Terminal Aerodrome Forecasts)

• Issued for the next 9 to 30 hours at intervals of 3 to 6 hours.

• Covers surface wind, visibility, weather conditions, cloud cover, and temperature predictions.

3. Meteorological Briefing (Met Briefing)

• Provides pilots with weather-related information for flight planning.

• Includes upper-level weather conditions, wind patterns, and significant meteorological updates.

Problems and Solutions in Air Traffic

Along with safety concerns, flight delays are a major issue in air traffic in India. Many times, these delays occur due to adverse weather conditions. As a member of the International Civil Aviation Organization (ICAO), it is mandatory for the India Meteorological Department (IMD) to provide high-quality weather services to aviators in accordance with ICAO guidelines. These services include weather-related information, forecasts, and more.

As per Annex-III of ICAO, the IMD provides two types of weather reports: current weather conditions and weather forecasts. All these services are offered under the supervision of the Directorate General of Civil Aviation (DGCA). In this regard, the IMD must work in coordination with the Airports Authority of India (AAI) and other agencies to deliver high-quality weather services using advanced technology and modern equipment.

This is not only a regulatory requirement but also a social and moral responsibility for officials like us, so that we can contribute to providing a comfortable air travel experience for both citizens and international travelers.

To enhance services, several modern instruments such as radars, AWOS (Automated Weather Observing System), RVR (Runway Visual Range) devices, and Automatic Message Switching Systems (AMSS) are being utilized to deliver weather information promptly. Additionally, online weather services have been introduced as a part of service upgrades, ensuring that the department and concerned authorities fulfill their responsibilities effectively.

Let us pledge today to assure our fellow citizens of a safe and fearless air travel experience.

-R. B. S. Narayan, Meteorologist (Retd. IMD), D-401, Pyramid City-3, Besa Pipla Road, Nagpur-37