Up in the skies or on the ground, when the weather gets seriously bad, there’s no substitute for experience. CAPTAIN A. RANGANATHAN on the dangers of weather-flying in the wake of a spate of recent accidents which have claimed many lives recently including that of the Andhra Pradesh Chief Minister Y.S. Rajasekhara Reddy.

Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so. — Douglas Adams

God created birds to fly. Man chose to build machines that intruded into this region. India, which has always been considered a “Blessed land”, has benefited immensely from the covering shadow that the divine blessings has provided to our aviation. When you consider several near disasters that Indian aviation has escaped from, you have to start believing in divine intrusion. Of late, what is worrying is the decline in the level of experience and training standards.

On 3rd September 2009, the helicopter carrying the chief minister of Andhra Pradesh, crashed into the hills and all five on board died. The helicopter was deviating and descending to a lower level to avoid the heavy thunderstorm that it encountered. Taking the deviation on the side which produces the maximum downdraft and also in an area where high terrain exists, resulted in the crash. During the last 15 years, several fatal accidents involving General Aviation aircrafts or helicopters carrying political leaders have perished in bad weather. They have all been the result of inadequate training and experience in operations in adverse weather conditions. The regulator has failed to implement stringent safety and training standards for all these operations. We refuse to learn from experience.

Behind the silver lining

There is an old saying, “Every cloud has a silver lining”. This may be true in other contexts but in flying, every cloud has a hidden lining. What appears beautiful when you are far from the danger can be lethal if you enter into the cloud with a silver lining. The recent Air France 447 crash in the Atlantic Ocean on June 1 is a pointer. The way in which the aviation world has been rocked in recent times by the weather phenomena makes one wonder whether we really understand how to deal with nature. 2009 has been a year when aircrafts have been battered by turbulence in the air, near the ground, and in the financial world. The last category is man-made while the first two are entirely due to nature.

A recent study published by the National Aerospace Laboratory (NLR) in the Netherlands, brings out several interesting statistics. They found that 43.8 per cent of non-fatal and 13.3 per cent of fatal accidents were weather related for aircrafts weighing over 27,000 kg. For large aircrafts, more than 55 per cent of the accidents happened during the “en route” phase of the flight while for small aircrafts more than 27 per cent took place in the landing phase of the flight. In the en route stage, more than 83 per cent of the accidents took place due to turbulence and six per cent due to thunderstorms. In the landing phase, they found 31 per cent were due to slippery runway conditions, 23 per cent due to rain and 27 per cent due to winds.

No substitute

Theoretical knowledge can never replace experience when you deal with nature. The weather conditions that aircrafts experience change every few minutes. Weather is a science but weather flying is an art. This art can be perfected only through experience in actual conditions. Fear of flying engulfs passengers whenever their flight encounters adverse weather conditions. There is a small percentage of pilots who are also weather shy. The fear can get accentuated when you are piloted by persons who have never experienced an encounter with adverse weather.

Weather flying can be described by the three corners of a triangle representing the following important factors:

The weather: A dynamic factor with countless variables.

The aircraft: With fixed parameters like limitations, speeds, thrust etc.

The human element: The pilot, to modify the fixed elements to match the variables in weather conditions.

Only experience and training will bring the human element to the required level of proficiency. Having been “baptised by the fire”, some of us can speak with authority on the experience of flying in severe weather conditions. Landing on two occasions, during a raging cyclone in the 1970s, landing during a severe squall in Singapore, landing during a typhoon in Hong Kong and encountering the most severe of thunderstorms, “The Norwester” in Northeast India and surviving the encounters are lessons that one can never forget. Sharing these experiences in training gives the ultimate pleasure .

The last two years have been very painful as far as aviation is concerned. Starting with the TAM airlines crash in Sao Paulo in July 2007 which killed 197 people, we have had a string of weather-related accidents. Some have been lucky with few fatalities but in others several lives have been lost. Several flights have encountered severe turbulence, resulting in injuries to several passengers or crew. There have been accidents due to misunderstanding of automation in the cockpit. The following details of the crashes this year highlight the danger of weather flying:

On February 25, 2009, a Turkish airline Boeing 737-800 crashed while landing at Amsterdam airport. In the cockpit were three pilots, a training captain, a trainee co-pilot and another co-pilot in the jump seat. The weather conditions during landing was a drizzle. The aircraft crashed short of the runway when the pilots did not recognise that the engine thrust had retarded to idle, due to a malfunction in the autoflight system. The three pilots and another six passengers died while 25 received serious injuries when the aircraft literally dropped down from a few hundred feet off the ground.

On March 23, 2009, a Federal Express MD-11 crashed while landing on a wet runway amid strong cross wind conditions in Narita airport in Tokyo. The landing was witnessed by many on the television. Both pilots were killed when the aircraft catapulted on one wing.

On June 1, 2009, the Air France flight AF 447 crashed into the Atlantic Ocean killing all 228 on board. The flight had three pilots, one captain and two co-pilots. Airlines in some countries carry an additional co-pilot to relieve a captain during flight, to cater for the extended duty time limits. It is likely that AF 447 had two co-pilots in the cockpit at the time of the crash. The aircraft entered a region of severe thunderstorm activity and crashed. Why did the crew enter that area is a mystery. The black boxes have not been located yet and that is going to be very big hurdle in the investigation.

Unexplored possibility

A possible theory that the investigators do not seem to be taking note of is the airflow near a huge thunderstorm cloud. Theoretically, the core of the cloud has strong updrafts, which get super-cooled. The resulting downdraft of a strong air mass is of super-cooled air and probably hail. This comes down on the portion of the cloud that is anvil shaped. This clear area has proved to be the undoing of several flight crew. You encounter severe turbulence and possible loss of engine thrust and speed.

All modern jet engines have electronic engine control called FADEC (Full Authority Digital Engine Control). It takes the ambient temperature conditions to set the limit for engine thrust. If the temperature increases due to a warm air mass, the FADEC will bring the thrust down to prevent exceeding the engine thrust limits. AF 447 flew in the vicinity of an exceptionally severe thunderstorm cloud, towering over 57,000 feet. The very strong updraft inside the core would have come down as a strong downdraft of warm air. The resultant speed loss due to the downdraft plus the thrust decay in the engine would have dropped the speed very rapidly.

A pilot who has experienced this and survived would recognise the conditions immediately. A rapid loss in altitude is the only way to recover if this downdraft extends over a large area. The two inexperienced pilots in the cockpit may not have realised this and got into a classic “Jet upset” conditions in severe weather. The actual truth will be known only when the black boxes are found. Until then, we have to survive with the theory that is going around on the failure of the “Pilot probes”.

On June 30, 2009, a Yemenia Airbus A-310 crashed while making an instrument approach for landing in rain conditions. The aircraft, while making a second approach, crashed into the Indian ocean. All the 11 crew and 141 passengers died while one passenger survived miraculously.

Two Qantas have encountered severe turbulence while en route, resulting in injuries to passengers and unknown damage to the aircrafts. A Continental Airlines flight had also encountered severe turbulence, resulting in injuries to passengers. Several other airlines have encountered severe turbulence in flight.


Global warming has changed the world weather. Nothing can be predicted — the seasons, the monsoons or what kind of weather an aircraft is likely to encounter en route. The lack of clear foresight in the perceptions of the regulators in India is a worrisome factor. In their enthusiasm to please the airline owners, the safety requirements are compromised. Required experience levels have been watered down and we can have two pilots who have never encountered adverse weather conditions manning the cockpit. One of the factors that has been identified in weather flying is the “startle factor”. A young 19- or 20-year-old co-pilot without any experience and a new inexperienced captain who might be equally startled, are not likely to provide a confident crew in the front!

Our regulations permit a raw pilot with just 200 hours on a light single-engine trainer aircraft and the basic commercial pilot’s license to be a co-pilot of a large jetliner. He undergoes around 25 hours of simulator training on the airline jet trainer and then, after just a minimum number of flights under supervision of a training captain, he is let loose on the routes with passengers on board. To transition from an aircraft weighing just 600 kg, travelling at speeds less than 200 kmph to a jet aircraft weighing 80,000 to 3,00,000 kg travelling at 900 kmph takes a lot of experience, especially when confronted by adverse weather conditions. They would never understand the effect of inertia of a large mass.

Relaxing requirements

The recent circular on the experience levels of foreign pilots is another clear pointer to their lack of understanding of the dangers. Permitting a mere 2,000-hour captain with just 100 hours on the type of aircraft is playing with safety. A captain who has flown 1,900 hours on a turbo-prop aircraft, flying at lower altitudes and at lower speeds, in unlikely to perform to the required level while flying a high performance jet aircraft at high altitudes and speeds which may be more than double of what he has experienced. Even a captain who has flown a different type of jet most of his career, is bound to revert to old habits when fatigue takes over.

Our regulations require just a minimum total cockpit time of 500 hours between a captain and the co-pilot. You may have an expatriate captain with just 100 hours on the type of aircraft (Boeing 737-800/900, Boeing 777 or Airbus 319/320/321/330) with a 400 hour co-pilot. Both might never have experienced a flight in adverse weather conditions. Handling a heavy aircraft through an active thunderstorm zone requires a lot of skill and experience. Modern aircrafts have very good instrumentation and safety features. However, if a failure of these devices takes place, as it did on the fatal Air France flight, your survival depends entirely on God’s mercy.

Pete Seeger, the famous folk singer once said: Education is when you read the fine print. Experience is what you get if you don’t. Only time will tell if we are a safe aviation community when flying in adverse weather conditions.


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