 |
|
The Air India AI 171 plane crash, a tragic event that claimed the lives of nearly all passengers, has been the subject of intense scrutiny and investigation. While initial reports and paraphrased excerpts suggested possible pilot error, aviation expert Richard Godfrey has presented a compelling analysis that points to a different root cause: the premature deployment of the Ram Air Turbine (RAT) in conjunction with water ingress into the aircraft's electronic equipment bay. Godfrey's findings, detailed in an interview with Geoffrey Thomas, shed light on the complex sequence of events leading to the crash and underscore the importance of stringent maintenance protocols and adherence to safety directives. The Aircraft Accident Investigation Bureau (AAIB) preliminary report, released a month after the London-bound aircraft crashed, provided a timeline of events leading up to the disaster. The report indicated that the aircraft requested pushback and startup clearance at 1:13 pm, followed by confirmation from the pilots that they would require the full length of Runway 23. ATC granted pushback at 1:13:13 pm and startup clearance at 1:16:59 pm. Taxi clearance was granted at 1:25:15 pm, and the aircraft was instructed to line up on Runway 23 at 1:33:45 pm. Takeoff clearance was given approximately four minutes later. However, just two minutes after lifting off, the pilots issued a MAYDAY call and the aircraft crashed seconds later. The rapid succession of events made it impossible for ATC to establish communication with the flight crew. A critical observation in the report was the simultaneous shutdown of both engines within one second of each other after the fuel supply was cut off. Attempts were made to relight the engines, but they proved unsuccessful. The engines, recovered from the crash site, were found in the “Run” position. The cockpit voice recorder captured a conversation between the pilots, with one asking the other why the engines had been cut off. The second pilot denied having done so. This seemingly inexplicable event became a focal point of the investigation, prompting Godfrey to delve deeper into the data to uncover the underlying cause. Godfrey's analysis hinges on the timing of the RAT deployment. He observed that the RAT was auto-deployed at approximately 1:38:47 pm, based on a comprehensive review of data, including the preliminary report and CCTV footage from the airport. According to the EAFR data, both engines' N2 values fell below minimum idle speed, and the RAT hydraulic pump began supplying hydraulic power at 08:08:47 UTC (1:38:47 pm IST). Godfrey emphasized that the preliminary report failed to adequately explain the timing and reason for the RAT deployment, although it did include an image showing the RAT in its extended position. Godfrey clarified that the screenshot depicting the RAT in its extended position was taken approximately 2.5 seconds after the RAT hydraulic pump began supplying hydraulic power. He reached this conclusion by synchronizing multiple datasets, including the preliminary report's FDR and ATC logs (accurate to the nearest second, ±0.5 seconds), FlightRadar24 ADS-B data (precise to the millisecond, ±1 ms), and high-frame-rate airport security CCTV footage recorded at 29.921 frames per second, accurate to within 33 milliseconds. Godfrey mapped the CCTV camera's field of view from the preliminary report, noting that the location was 229 metres from the Runway 23 end. This meticulous analysis allowed him to pinpoint the precise timing of the RAT deployment and its relationship to other critical events. The significance of the RAT deployment lies in its function as an emergency power source. The RAT provides emergency hydraulic or electrical power during a loss of main power, such as dual‑engine failure. It can deploy automatically or manually, giving pilots enough power to control the aircraft and attempt a safe landing. However, it only supplies essential systems and needs enough speed and altitude to work effectively. If the failure occurs at very low altitude or just after takeoff, the RAT might not generate enough power quickly enough to prevent a crash. In the context of the AI 171 crash, the premature deployment of the RAT suggests that a significant power loss had already occurred, triggering the emergency system. This, coupled with the low altitude and airspeed at the time of the incident, likely contributed to the pilots' inability to regain control of the aircraft.
While the RAT deployment provides a crucial piece of the puzzle, Godfrey's analysis extends beyond this single event. He investigated six possible root causes behind the crash, ultimately identifying water ingress in the Electronic Equipment (EE) bay as the most probable cause. Godfrey based this conclusion on recent Airworthiness Directives (ADs) from 2025 that specifically address this issue in Boeing 787 aircraft. The directive warns that installed water line couplings in lavatories or galleys can cause leaks, allowing water to migrate into the EE bay. Once there, the water can trigger electrical failures and potentially lead to a complete loss of power. The relevance of this AD to the AI 171 crash lies in the potential for water ingress to disrupt critical electrical systems, including the Engine Electronic Control (EEC) and the Full Authority Digital Engine Control (FADEC). These systems are responsible for controlling engine performance and fuel supply. A disruption to these systems could explain the simultaneous engine shutdown observed in the preliminary report. Godfrey considered other possible causes, including a shared DC bus failure. While technically possible, this scenario would require the rare, simultaneous failure of multiple contactors (electrical switches). He ranked IPC Faults (breaker trips or electrical arcs) and Software-Controlled Isolation as low-probable causes, citing discrepancies in the timeline of events and the absence of historical cases. He also dismissed GCU Software Overflow and PRB-A water ingress as possible causes, based on the aircraft's recent power-down history and the falsity of a purported Boeing service bulletin. Godfrey's comprehensive analysis led him to conclude that the most likely cause of the accident was water ingress into the electronic equipment (EE) bay during rotation. This water ingress, he believes, led to a simultaneous electrical disruption of the EEC and FADEC, as well as the electrical power buses feeding both systems. This disruption resulted in a near instantaneous shutdown of both engines at low air speed and low altitude. The limited energy margin at such a critical phase of flight left insufficient time for the FADEC-controlled engine relight sequence to restore thrust and prevent a loss of control and terrain impact. The engine relight sequence typically takes at least 20 seconds, if not longer, making it impossible to recover from the dual engine failure at such a low altitude.
Importantly, Godfrey's analysis exonerates the pilots from blame. He firmly states that the root cause was not pilot error. While there may have been some discussion in the cockpit about who did what and when, he believes that the pilots were taken by surprise by the sudden and unexpected engine shutdown. He emphasizes that the event was preventable, highlighting the critical role of maintenance oversight and compliance with safety directives. The cockpit voice recording, in which one pilot asks the other why the engines were cut off, further supports the notion that the event was unexpected and beyond the pilots' control. The flight was commanded by 56-year-old Captain Sumeet Sabharwal and 32-year-old Clive Kunder as the First Officer, experienced aviators with a combined total of over 19,000 flying hours, nearly half of which were spent operating Boeing 787 aircraft. Both pilots were properly rested and had cleared health checks before the flight, further reducing the likelihood of pilot error. Godfrey attributes the tragedy to lapses in maintenance oversight and non-compliance with FAA Airworthiness Directive 2025. He notes that this directive explicitly warns about water ingress into the EE bay and calls for improvements to the cabin ceiling to prevent such incidents. The failure to adequately address this known vulnerability may have contributed to the conditions that led to the crash. In conclusion, Richard Godfrey's analysis of the Air India AI 171 plane crash provides a compelling alternative to the initial assumption of pilot error. By meticulously analyzing various data sources and considering multiple potential causes, he has presented a strong case for water ingress into the electronic equipment bay as the primary factor leading to the dual engine failure and subsequent crash. His findings underscore the importance of rigorous maintenance protocols, adherence to safety directives, and proactive measures to mitigate known vulnerabilities in aircraft systems. The tragedy serves as a stark reminder of the potential consequences of neglecting these critical aspects of aviation safety and the devastating impact that such lapses can have on human lives.