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The Air India Boeing 787-8 crash in Ahmedabad, a tragic event marking the deadliest disaster for an Indian airline in decades and the first-ever crash involving this aircraft model, continues to be investigated with meticulous detail. A pivotal piece of evidence that has recently emerged is a video captured by Aryan Asari, a class 12 student and amateur photographer, during the final moments of the ill-fated flight. This video, sourced directly from Asari's phone, presents a clearer view of the events preceding the crash and has the potential to challenge previously held theories regarding the cause of the accident. One of the key areas of speculation among aviation experts has been the deployment, or lack thereof, of the Auxiliary Power Unit (APU) and the Ram Air Turbine (RAT), both of which serve as emergency power sources on the aircraft. The video appears to suggest that the RAT, specifically, was not deployed, aligning with the testimony of the sole survivor who recounted a loud bang followed by a blackout, and then the emergence of a green light within the cabin. This evidence lends credence to the possibility of a significant equipment-related emergency that occurred during the flight's initial ascent. The RAT's purpose is to provide essential power to the aircraft in situations where primary and secondary power sources have failed. It's a wind turbine positioned behind the landing gear console, designed to automatically deploy into the airstream and generate power. The fact that it appears to have deployed suggests a critical system failure on board. A regulatory source noted that the loud bang described by the survivor could have been the sound of a lower hatch giving way as the RAT deployed automatically. However, the source also acknowledged that other triggers could have caused a similar sound. The deployment of the RAT indicates a dire situation, potentially involving a total electrical failure, a significant hydraulic failure, a dual-engine failure, or a combination of these and other contributing factors. While dual-engine failures are exceedingly rare, the appearance of insufficient lift and a loss of thrust has brought this possibility back into consideration for investigators. The focus now shifts to the question of whether a dual-engine failure, previously deemed improbable but theoretically possible, played a significant role in the crash.
Civil Aviation Minister K Ram Mohan Naidu stated during a media briefing that investigators will be examining all plausible theories in their pursuit of determining the cause of the accident. However, he also emphasized that it is too early to arrive at any definitive conclusions based solely on the preliminary video evidence. Modern aircraft are highly complex machines, and a thorough and meticulous investigation is necessary to uncover the precise cause or combination of causes that led to the crash. The clearer video evidence obtained from Asari serves as a valuable clue for investigators, providing them with an additional piece of the puzzle to consider as they delve deeper into the data and analyze the available information. Several potential scenarios are being explored, including the possibility of fuel contamination or fuel line blockage, which could have resulted in the engines being starved of fuel and experiencing a sudden shutdown. An airport source mentioned that the refueling process for the flight took longer than usual, lasting approximately 42 minutes. However, other sources indicated that this duration was not necessarily out of the ordinary for a long-distance international flight with a full passenger load. Another area of investigation is the potential for bird strikes. While Ahmedabad airport does have a higher-than-average rate of bird hits compared to other airports in India, it would be extremely rare for a bird strike to disable both engines simultaneously. The available footage does not appear to support the theory of a significant bird strike, and there is no evidence of bird carcasses found either at the accident site or on the airfield. The deployment of the RAT is typically a last resort, providing basic power to the aircraft when all other systems have failed. While the RAT is most effective at higher altitudes, giving pilots sufficient time to reach the nearest available airfield, the pilots of Flight AI-171 did not have that luxury. The plane had just taken off and was at an altitude of only 625 feet, or approximately 400 feet when accounting for the Ahmedabad airport's 200-foot elevation, before it crashed shortly thereafter.
Aviation accidents rarely have a single cause, and they usually involve a series of events that occur together or one event leading to another. Before the emergence of Asari's clearer video, experts were increasingly focusing on the possibility that the landing gear of AI-171 was down and the flaps were not retracted properly after the aircraft lifted off the runway. Some speculated that there might have been an erroneous retraction of the flaps instead of the gear. The apparent lack of lift, as described by the sole survivor who said the plane seemed to hang in the air before crashing, supported this theory. However, the deployment of the RAT changes the dynamics of the investigation entirely. Based on the available videos, the rate of rotation, which involves pulling back on the yoke or center stick to lift the nose wheel off the ground during takeoff, appeared to be normal. However, the landing gear not being retracted even after the aircraft became airborne is when problems seem to have begun. The landing gear should be retracted by the time the aircraft reaches 100 feet after achieving a positive rate of climb, which is when the captain gives the command to retract the landing gear to the co-pilot. Having the gear down, coupled with an incorrect wing flap configuration, would result in insufficient lift and significant drag. Even a partial loss of thrust could have further compromised lift, given that the landing gear was extended. The fact that the pilots pulled the nose up towards the end suggests a desperate maneuver, as the terrain warning would have started sounding in the cockpit. While the Flight Data Recorder (FDR) has been recovered and will provide extensive insights into the reasons behind the crash, the Cockpit Voice Recorder (CVR), the other black box, will also be critical to the investigation. The CVR will reveal details of the pilots' interaction with each other and with air traffic control, as well as the warnings and alarms that sounded in the cockpit before the fatal crash. Together, the FDR and CVR data are expected to provide a comprehensive understanding of the events leading up to the crash, helping investigators piece together the sequence of events and identify the factors that contributed to the tragic accident. This investigation will be crucial not only for understanding the causes of this specific crash but also for improving aviation safety and preventing similar accidents from occurring in the future.