Air India Crash: Three Key Theories

Catastrophe Over Ahmedabad: The 30-Second Flight of Air India AI171

A thorough probe will eventually uncover what doomed Air India Flight AI171 during its journey from Ahmedabad to London's Gatwick airport. Thursday afternoon's events, however, highlight a stark aviation reality: the period following departure is the most demanding and perilous. Soon, Indian accident investigators will welcome their international counterparts. Specialists from the UK and the US are scheduled to collaborate on establishing the crash's cause. The Boeing 787-8 Dreamliner fell just 1.5 kilometres away from Sardar Vallabhbhai Patel International Airport, transforming a standard departure into a national disaster.

This incident signifies a dark milestone. It is the inaugural fatal event involving a 787-8 Dreamliner since the model began flying commercially in 2011. The catastrophe on Thursday resulted in the deaths of 241 individuals on the aircraft and more among those below. Professionals in aviation and aviators stationed in India have started to analyze the sparse available information. These pilots, with extensive experience operating the 787-8 model out of the nation's global hubs, are concentrating on what could have caused the jet to plunge into apartment blocks in central Ahmedabad only moments after it became airborne.

A Struggle for Height

The aircraft was under the command of Captain Sumeet Sabharwal and his co-pilot, Clive Kundar. Both men were seasoned flight crew. Mr Sabharwal had a career spanning over two decades as a pilot for commercial airlines, having accumulated in excess of 8,000 hours of flight time. With 242 individuals on board, the jet moved towards the runway at the Ahmedabad global air terminal. Departure occurred at 1:39 PM local time (08:09 GMT). The flight was heavily laden for its long-distance trip to London.

India's Home Affairs Minister, Amit Shah, mentioned that the aircraft transported 100 tonnes of fuel, which was nearly its maximum capacity. Right after getting airborne, the flight deck sent out a distress signal. No subsequent communications came from the plane. The reason for the mayday remains uncertain, though the single individual who survived the ordeal described hearing a substantial noise while the jet found it difficult to climb. Authenticated video later depicted the aircraft traveling dangerously low above a populated neighbourhood before it vanished behind vegetation and structures, preceding a massive blast.

The Final Seconds

The last data sent from Flight AI171 indicated the aircraft achieved a peak height of just 190 meters (625ft). It subsequently began to lose altitude. The flight crew would have had no opportunity to respond to a total power loss from both engines. Security camera footage established that the airplane was in the sky for only half a minute. The jet came down in a heavily built-up neighbourhood. Early images revealed apartment buildings with severe damage in a district that also housed medical facilities and governmental structures. The location of the crash instantly became a scene of frantic rescue activity.

An International Investigation Convenes

The inquiry into the AI171 disaster will adhere to a strict international protocol. This framework is detailed in Annex 13 of the Convention on International Civil Aviation, often called the Chicago Convention. This agreement specifies that the country where the accident happened—in this instance, India—directs the safety inquiry. It also provides formal rights for other involved nations to join. These participants include the manufacturing state (the United States, for Boeing), the operator's state (India), and the destination state (the United Kingdom). This structure ensures a transparent and multi-faceted investigation.

The main purpose of an Annex 13 inquiry is not to allocate fault but to find the cause and stop similar future events. India's Directorate General of Civil Aviation (DGCA) will thus collaborate with official representatives from the NTSB in the US and the AAIB from the UK. These groups consist of specialists in flight operations, airframe structures, engines, and aircraft systems, guaranteeing a thorough examination of every flight aspect. The international makeup of the team is meant to stop any one nation from having excessive influence on the conclusions.

Image Credit - Aviation Week

The Search for the Black Boxes

Key to the inquiry is finding the airplane’s two flight recorders. Often called "black boxes," these units are in fact coloured bright orange to help find them in wreckage. The devices include the Cockpit Voice Recorder (CVR) and the Flight Data Recorder (FDR). They are protected inside crash-survivable memory units, usually situated in the aircraft's tail section, an area that frequently sustains the least impact. An underwater locator beacon is fitted to each unit, which activates when submerged in water.

The CVR documents the complete audio environment within the cockpit, such as crew dialogue, radio messages, and any audible warnings or system notifications. Current CVRs store the final two hours of sound on a repeating loop. The FDR documents thousands of different airplane parameters, tracking everything from altitude, airspeed, and direction to engine output and flight control positions. These recorders together will let investigators piece together a precise timeline of the flight's final, tragic seconds and deliver essential, objective information to comprehend the failure sequence.

The Dreamliner's Unblemished Record

Prior to this tragedy, the Boeing 787 Dreamliner maintained a perfect record regarding fatal accidents since it was introduced in 2011. This crash is the first to cause passenger deaths. The 787 stands as one of the most advanced jets flying, recognised for its economical fuel use and its construction from lightweight composite materials. More than 1,100 Dreamliners operate worldwide, having flown over 875 million passengers. The model, however, has faced safety reviews before. In 2013, the entire global fleet was grounded for a period due to problems with its lithium-ion batteries overheating.

More recently, production standards and quality assurance at Boeing facilities have been subjects of concern. Allegations suggested that subpar components were installed on the 787 assembly line and that the emergency oxygen equipment had a significant failure rate. While incidents not involving fatalities have taken place, such as an engine shutdown on an Air India 787 in 2023 and a sudden mid-air drop on a LATAM Airlines 787, the airplane's safety history concerning fatal crashes was, until this point, spotless.

Theory One: A Rare Dual Engine Failure

The limited footage available of the airplane's difficulties has prompted speculation about the exceptionally uncommon scenario of a failure affecting both engines. The videos seem to depict the jet not producing enough thrust to climb as expected. A near-total power loss could account for this situation. Malfunctions of two engines at once are practically unknown in contemporary aviation. The most well-known case is still the 2009 “Miracle on the Hudson,” where US Airways Flight 1549 landed safely on the Hudson River following a collision with birds that disabled both engines after departing LaGuardia Airport in New York.

Such a malfunction might arise from issues like tainted fuel or an obstruction in the mechanism for fuel metering. If the specific flow of fuel to the engines is cut off, this can result in the engines flaming out and ceasing to operate. Other specialists, however, are still dubious, noting the absence of clear proof in the video evidence. A simultaneous malfunction in both engines is regarded as an exceedingly unusual occurrence. GE Aerospace, the maker of the engines, has sent personnel to India to aid the inquiry.

The Role of the Ram Air Turbine

When a catastrophic loss of engine power occurs, airplanes such as the 787 are equipped with a final emergency system: the Ram Air Turbine, or RAT. The RAT is a compact propeller-driven turbine stored within the fuselage or wing. It can be extended automatically or by the crew if the two main engines cease to function. Once extended, the rush of air spins the turbine, which then drives a hydraulic pump or an electrical generator. This action does not bring back engine thrust but it does supply crucial power to vital systems, like primary flight controls and essential flight displays.

The power level generated by the RAT hinges on the airplane's speed; slower speeds produce less power. There are questions about whether the RAT on Flight AI171 was activated. Its activation would be compelling evidence of a total loss of main engine power. Investigators will closely inspect the wreckage for any indication of its deployment. In the interval between the loss of primary power and the RAT's activation, the airplane’s batteries supply temporary electricity to the most essential systems.

Image Credit - Hindustan Times

Theory Two: A Catastrophic Bird Strike

A major impact with birds is another possibility. Impacts with avian wildlife can present an immense danger, especially during the vital departure and arrival stages of flight. If a sizable bird or a group of them gets ingested by an engine, it can inflict catastrophic damage and an instant loss of power. The airport at Sardar Vallabhbhai Patel is infamous for its large bird population. This view has been shared by numerous aviators from India with regular experience flying out of the airfield.

Official figures corroborate these firsthand accounts. The Ahmedabad airport has consistently ranked high within the country for incidents where birds were struck. Recent statistics for 2023 revealed a significant 107% jump in strikes from the year before, with 81 events documented in the initial ten months alone. Unlawful waste disposal and pigeon racing in adjacent neighbourhoods have been identified as contributing issues.

The Hudson Comparison

While an impact with a bird is a credible reason for engine malfunction, the situation for Flight AI171 is vastly different from the Hudson River event. In that 2009 incident, the A320 jet hit a group of geese when it was at an altitude of around 2,700 feet. This provided the pilots with vital time and height to assess the problem, glide the unpowered airplane, and perform a controlled landing on water. Every one of the 155 individuals aboard survived. The crew operating the Air India jet had no similar advantages. Their airplane was at a significantly lower height and was still in its climbing phase.

The encounter, if one took place, would have happened when the airplane was most vulnerable. Carrying a substantial load of fuel and passengers, and at a reduced airspeed, no room for any mistakes would have existed. An impact with a bird seldom leads to a catastrophe unless both engines are affected at the same time. For the crew of Flight AI171, a malfunction in both engines at an altitude of only a few hundred feet would have created an unsurvivable situation, affording no time or space to guide the airplane to safety.

Theory Three: Flap Configuration Error

A third theory indicates a potential problem related to the flaps on the airplane. Flaps are movable panels on the back edge of the wings that are deployed for takeoff and landing. They boost both lift and drag, enabling the airplane to get airborne at a slower speed and over a shorter distance. Should the flaps have been improperly set for the departure, the heavily weighed-down Dreamliner would have found it immensely difficult to create the lift required to ascend after leaving the airstrip.

This problem would have been greatly exacerbated by the weather conditions in Ahmedabad. On the day of the incident, temperatures were getting close to 40°C (104°F). These high temperatures result in what aviation calls "hot and high" conditions. Hot air is less dense than cool air, a factor that lowers both engine output and the wings' ability to create lift. In these circumstances, the proper positioning of the flaps and full engine power are absolutely essential.

The Challenge of 'Hot and High' Takeoffs

High surrounding temperatures have a considerable negative impact on airplane performance. Air that is less dense requires the wings to travel faster through it to create an equivalent amount of lift. This makes a longer takeoff roll and a faster departure speed necessary. Concurrently, jet engines generate less power because the less dense air contains fewer oxygen molecules for burning fuel. For a completely full, long-distance flight such as AI171, taking off in that kind of heat would have already stretched the airplane's performance capabilities.

The flight crew would have needed to figure out their takeoff performance data with great care, considering the temperature and air density. These figures establish the necessary engine power setting and flap position. In such tough circumstances, a minor mistake in the jet's setup can lead to devastating results. The mix of a heavy airplane, a complete capacity of fuel, and hot, thin air provides zero margin for any kind of error during the departure phase.

The Takeoff Configuration Warning System

While a mistake with flap configuration might explain the airplane's inability to climb, modern jets like the Boeing 787 come with advanced safety features to stop such errors. The Takeoff Configuration Warning System (TCWS) is a vital protection measure intended to notify the crew if the airplane is not properly prepared for departure. This system checks the position of the flaps, slats, speed brakes, and stabiliser trim. If the pilots push the thrust levers forward for takeoff while any of these systems are in an unsafe state, a loud, pulsing horn will sound inside the cockpit.

For the flap error theory to hold true, the crew would have needed to either overlook or ignore this vital alert. A malfunction of the warning system itself is another, though less likely, possibility. A mistake like that, however, would be exceptionally uncommon. Pilots are responsible for positioning the flaps before they take off, and numerous checks and established steps exist to confirm the proper configuration. If improperly set flaps were indeed the cause, it would strongly suggest the possibility of a mistake made by the crew.