On Friday, a helicopter of 'Trans Bharat Aviation' met with an accident while returning from Badrinath to Dehradun in Chamoli district of Uttarakhand. The pilot and 5 pilgrims died in the accident. The helicopter took off from Dehradun at around 12.20 pm and reached Badrinath at around 1.11 pm. Here 5 passengers sat and the helicopter took off for return. During this time the plane went out of control and fell.
Officials have cited bad weather as the initial reason for the accident. Officials of the Air Accident Investigation Bureau (AAIB) and the Directorate General of Civil Aviation (DGCA) are trying to find out whether the accident happened due to bad weather or due to a faulty engine or any mistake by the pilot.
Initial reports from the Chamoli district administration suggest that the helicopter got stuck in bad weather in the Hathi Parvat area and fell while descending. The Meteorological Department had issued an orange alert for Chamoli on October 30. The Meteorological Department has clearly said that there may be a danger of thunderstorm with lightning, hail and winds at the speed of 40 to 50 km per hour at different places. Flights were stopped in Badrinath Valley from 9 am to 12 noon due to bad weather. They were started again after the weather improved.
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Which question has not been answered yet?
AAIB team is searching the debris. The black box has not been found yet. The debris has been almost completely destroyed. The tail area of the helicopter is left. The accident site is 20 to 22 km away from the nearest road. People are reaching there through risky routes on foot. DGCA had announced after the accident that it would be mandatory to have a co-pilot in all charter helicopter flights for the rest of the season. Now single pilot will not be allowed in charter flights. 11 operators of Char Dham route have objected to this rule and said that they will stop the services from November 2.
After the Uttarakhand accident, a question is being raised again and again that why helicopters crash?
The International Helicopter Safety Foundation (IHSF) and the Federal Aviation Administration (FAA) have conducted several studies on helicopter accidents. A common thing came to light in different studies that accidents happen due to three reasons. Firstly, the engine may fail, secondly, the weather may be bad and thirdly, the pilot may fail to take the right decision at the right time. How, understand-
Why do helicopter accidents happen?
Aeronautical engineer Abhishek Rai, referring to the study of these institutions, said, 'A major reason for helicopter accidents is human errors and bad weather. When suddenly dense fog or clouds appear, the pilot cannot get the correct idea of direction and altitude. In such a situation, due to lack of visibility ahead, the flying helicopter often collides with mountains, trees or electric wires. Many times a pilot's mistake like losing control during flight directly results in a major accident.
He said, 'Technical fault and complex design of the helicopter is also a reason for the accident. The rotor, tail rotor or gearbox are the most sensitive parts in a helicopter. If any one of these malfunctions, it becomes very difficult to handle it immediately. Single-engine aircraft are most at risk. Sometimes the helicopter gets trapped in the vortex of air created by its own wings and starts falling rapidly. Helicopters fly very close to the ground, so pilots have very little time to handle any technical glitches or setbacks. Before anything can be done, the plane becomes a victim of an accident.
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When do accidents happen due to pilot error?
Aeronautical engineer Abhishek Rai said, 'According to a report by the Federal Aviation Administration, 5 to 10 percent of accidents occur due to spatial disorientation. 90 percent of these are fatal. The human body is designed to maintain balance on the ground. The signals coming from the eyes, inner ear and muscle-joint sensors in the air sometimes do not match with each other. This gives wrong signals to the brain and the pilot gets confused.
Many times, after a slow and long turn, when suddenly straightened, it seems as if the plane is tilting in the opposite direction. After a long turn or spin, the brain feels that it has stopped rotating. When straightened, it feels like rotating in the opposite direction. The pilot relies on body sensations to make incorrect corrections and the aircraft may crash into the ground. Many times, due to excessive disorientation, the route of a plane crash is not decided and accidents occur. A sudden increase or decrease in speed gives a false feeling of going up or down. This can also happen during night takeoffs in dark skies. Incorrect response may result in a crash or stall.
Which helicopters are more risky?
Aeronautical engineer Abhishek Rai, referring to a report by Science Direct in the year 2021, said that it has been observed that single engine helicopters are the most risky. There is no chance of recovery after an engine failure. He said that multi-engine helicopters also fail but there are more chances that the accident could be averted.
What is the scientific reason for the accident?
Abhishek Rai said, 'Most accidents happen during short distance flights. 10 times more accidents occur in land flights than in sea flights. Small commercial helicopters have only one pilot. He flies by hand instead of using a computer or autopilot, which increases the margin of error. Models with single engine and fewer blades are more sensitive. Light helicopters, with a piston engine and low rotor blades, are difficult to handle when a sudden technical failure or gust of wind occurs. These helicopters are more sensitive.
Helicopters with single-engine, single-piston or reciprocating engines are considered the most risky and dangerous. Twin-engine helicopters are considered safe because if one engine fails, the other one acts as a backup. In single-engine helicopters, due to minor engine or fan failure, the pilot may not have time to recover due to reduced thrust. In complex conditions like heavy weight, adverse weather or high altitude, there is no scope for power reserve in these light engines. Planes meet with accidents due to loss of control.
Also read: Uttarakhand: Helicopter returning from Badrinath Dham crashed, 6 people were on board
What is the function of top and back wings?
The largest fan attached to a helicopter is called the main rotor. The fans at the rear are called tail rotors. The work of both types of wings is different. Both are connected to each other by doing different things. A fan lifts the helicopter off the ground and stops it in the air, creating thrust. The blades fitted in these help the helicopter to turn and change direction.
Engineer Abhishek Rai told that when the big fan above rotates rapidly in one direction, the entire body of the helicopter automatically starts rotating in the opposite direction. The small fan installed at the back keeps the body straight by pushing air from one side. This is why helicopters rotate back and forth instead of rotating in one place. The pilot increases or decreases the power of this small fan by pressing the paddle with his feet. With this, the helicopter can easily turn right or left while standing at one place in the air.
How many helicopters are there in India?
A report by the Indian Brand Equity Foundation (IBEF) suggests that there are about 90 helicopter operators in India, which include non-scheduled operators, private companies, state governments and public sector companies. They have a total of 280 turbine helicopters. This is a very small number compared to the 14,000 helicopters operating in the US. These are considered better and safer than helicopters with piston engines. There are more than 1 thousand helicopters in India but most of the commercial helicopters are single engine.