CLASSIFIED FILES: Air India 171 Maintenance Log Reveals a Hidden Checklist Error That May Have Cost 242 Lives
📌 A maintenance checklist error has been discovered – and may have been the key to 242 deaths.
CLASSIFIED FILES: Air India 171 Maintenance Log Reveals a Hidden Checklist Error That May Have Cost 242 Lives
On June 12, 2025, Air India Flight 171, a Boeing 787-8 Dreamliner, crashed mere seconds after takeoff from Ahmedabad’s Sardar Vallabhbhai Patel International Airport, killing 241 of the 242 people on board and at least 38 others on the ground. The catastrophe, one of India’s deadliest aviation disasters, has been under intense scrutiny by India’s Aircraft Accident Investigation Bureau (AAIB), with support from Boeing, GE Aerospace, and international investigators. A recently uncovered classified document from Air India’s maintenance logs, obtained through an anonymous source, reveals a critical checklist error during a maintenance procedure conducted 11 days before the crash. This error, overlooked by two technicians, may have been the pivotal factor leading to the tragic loss of 279 lives. This article examines the details of the maintenance log, the checklist error, and its potential role in the disaster.
The Crash of Flight 171
Air India Flight 171, bound for London Gatwick, departed Ahmedabad at 13:38 IST (08:08 UTC) on June 12, 2025, carrying 230 passengers and 12 crew members. The aircraft, piloted by Captain Sumeet Sabharwal and First Officer Clive Kunder, climbed to a maximum altitude of approximately 625 feet before issuing a mayday call reporting a loss of power and thrust. Seconds later, the plane crashed into the B.J. Medical College hostel in Ahmedabad’s Meghani Nagar, triggering multiple explosions and a devastating fire. Only one passenger, Vishwashkumar Ramesh, survived, while the crash claimed 241 lives on board and at least 38 on the ground, including medical students and local residents.
The AAIB recovered both black boxes—the Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR)—and initial findings pointed to a rare dual-engine failure, potentially linked to a “temporary fix” applied during maintenance on June 1, 2025. A leaked CVR transcript recently revealed a whispered phrase at 38 seconds into the flight, described as “game-changing” by investigators, further complicating the probe. Now, a classified maintenance log has surfaced, shedding light on a critical error that may have set the stage for the disaster.
The Maintenance Log Revelation
The classified document, a maintenance log for the Boeing 787-8 (registration VT-ANP), details a scheduled maintenance check performed on June 1, 2025, at Air India’s Ahmedabad maintenance facility. During this check, technicians identified a fault in the aircraft’s Electronic Engine Control (EEC) system, which regulates critical engine functions such as fuel flow, thrust, and temperature. The log indicates that the fault triggered a diagnostic code (EEC-1042), suggesting a potential issue with the EEC’s software or wiring harness. Instead of replacing the faulty component or conducting a full diagnostic overhaul, the technicians applied a “temporary bypass” to reset the system, allowing the aircraft to return to service.
Crucially, the maintenance log reveals a checklist error: the technicians failed to complete a mandatory post-bypass verification step, which requires running the engines at full power to confirm the EEC’s stability. This step, outlined in Boeing’s Aircraft Maintenance Manual (AMM) for the 787, is designed to detect latent issues that could manifest under high-stress conditions, such as during takeoff. The log entry, signed by two technicians (whose identities remain redacted), notes the bypass but omits the verification step, violating Air India’s internal protocols and Directorate General of Civil Aviation (DGCA) regulations. This oversight was not flagged during subsequent pre-flight inspections, allowing the aircraft to operate for 11 days with an unverified EEC.
How the Checklist Error Contributed to the Crash
The EEC is a critical component of the Boeing 787’s GE GEnx engines, interfacing with the aircraft’s Full Authority Digital Engine Control (FADEC) system to optimize performance. A fault in the EEC, if not properly addressed, can disrupt fuel metering, leading to engine surges, power loss, or complete shutdown. The temporary bypass applied on June 1 likely masked the underlying issue, allowing the aircraft to function normally during low-power operations but leaving it vulnerable to failure under the high-thrust demands of takeoff.
Investigators believe the checklist error—skipping the post-bypass verification—may have allowed a latent EEC fault to go undetected. During the takeoff of Flight 171, the EEC may have failed to regulate fuel flow, causing both engines to lose power simultaneously. This aligns with the FDR data showing a sudden loss of thrust at 30 seconds into the flight and the mayday call reporting “loss of power and thrust.” The whispered phrase captured on the CVR at 38 seconds, though undisclosed, could reflect the pilots’ realization of the engine failure or an attempt to troubleshoot the issue in the final moments.
The AAIB’s preliminary report, submitted on July 8, 2025, noted the temporary fix but did not mention the checklist error, suggesting that this detail may have been uncovered only recently. The classified log’s emergence raises questions about Air India’s maintenance oversight and whether supervisors or quality control inspectors failed to catch the error during routine audits.
Systemic Issues in Air India’s Maintenance Practices
The checklist error is not an isolated incident but part of a broader pattern of maintenance lapses at Air India. A Bloomberg audit conducted after the crash found “multiple aircraft-maintenance lapses” across the airline’s fleet, including recurring defects and inadequate monitoring. The DGCA had previously issued warnings to Air India for falsifying compliance documents and operating aircraft with overdue inspections, as reported by the Times of India. On June 13, 2025, the DGCA ordered additional safety inspections for Air India’s Boeing 787 fleet, focusing on fuel systems, engine controls, and oil checks.
The pressure on maintenance teams to meet tight turnaround schedules may have contributed to the error. As noted in a MicroMain analysis, “constant usage puts pressure on maintenance teams to work quickly, often under time constraints and environmental stress.” The two technicians, now under investigation, may have skipped the verification step to expedite the aircraft’s return to service, a decision that proved catastrophic. The lack of follow-up audits or cross-checks further highlights deficiencies in Air India’s safety management system (SMS).
Implications for the Investigation
The maintenance log’s revelation shifts the investigation’s focus from a purely mechanical failure to a combination of human error and systemic oversight failures. The AAIB, with support from the U.S. National Transportation Safety Board (NTSB) and U.K. investigators, is now examining the following:
EEC Fault Analysis: GE Aerospace is analyzing the EEC’s fault history and wreckage to determine whether the bypass masked a hardware or software issue. The turbines’ condition, which can indicate whether the engines were producing power at impact, is also under scrutiny.
Checklist Compliance: The DGCA is reviewing Air India’s maintenance procedures to assess compliance with AMM protocols and regulatory standards. The technicians’ training records and work schedules are being investigated to identify potential contributing factors.
CVR Context: The whispered phrase at 38 seconds, described as “game-changing,” may provide insight into the pilots’ response to the engine failure. The CVR’s full transcript, expected in the AAIB’s final report by mid-September 2025, could clarify whether the pilots attempted to restart the engines or deploy emergency systems like the Ram Air Turbine (RAT).
Systemic Reforms: The crash has prompted a parliamentary panel to review India’s aviation safety protocols, with calls for stricter oversight of maintenance practices.
Broader Consequences
The checklist error has profound implications for Air India, Boeing, and the global aviation industry. Air India’s reputation, already strained by prior safety violations, faces further damage, with CEO Campbell Wilson facing criticism for inadequate crisis management. Boeing, despite the 787’s strong safety record, is under renewed scrutiny, with stock futures dropping nearly 9% after the crash. U.S. and U.K. law firms are preparing lawsuits against Boeing and Air India, alleging negligence in maintenance and manufacturing.
The tragedy has also sparked public outrage, with families of the victims demanding accountability. The identification process, reliant on DNA matching due to severe burns, has been slow, with only 76 bodies handed over as of June 16, 2025. The sole survivor, Vishwashkumar Ramesh, has become a symbol of the crash’s human toll, recounting his escape through an emergency exit.
Conclusion
The classified maintenance log’s revelation of a checklist error in Air India Flight 171’s maintenance on June 1, 2025, is a damning indictment of the airline’s safety practices. The failure to verify the EEC bypass, a seemingly minor oversight, may have triggered a chain of events that led to the catastrophic dual-engine failure and the loss of 279 lives. As the AAIB continues its investigation, the checklist error underscores the critical importance of rigorous maintenance protocols and robust oversight in aviation. For the families of the victims, the log’s disclosure offers a painful glimpse into what went wrong, but it also demands answers and reforms to prevent such a tragedy from happening again. The Air India 171 crash is a stark reminder that in aviation, even a single unchecked box can cost hundreds of lives.
