Air India Flight 171: Radar Data Reveals Catastrophic 4,800-Foot Descent in 42 Seconds
On June 12, 2025, Air India Flight 171, a Boeing 787-8 Dreamliner, crashed 32 seconds after takeoff from Ahmedabad’s Sardar Vallabhbhai Patel International Airport, killing 241 of 242 passengers and crew and 19 people on the ground. A preliminary report by India’s Aircraft Accident Investigation Bureau (AAIB) identified the movement of both fuel control switches to the “CUTOFF” position as the initiating event, causing a dual-engine failure. Recently analyzed radar data reveals a staggering descent of 4,800 feet in just 42 seconds, despite the cockpit retaining power and flaps remaining deployed. A haunting silence followed the final moments, deepening the mystery of this tragedy. This article explores the radar data, the cockpit’s status, and the implications of the eerie silence, drawing on the latest findings and a leaked audio clip.
Radar Data: A Precipitous Descent
Flightradar24 and other aviation tracking sources indicate that Flight 171 reached a maximum pressure altitude of approximately 625 feet above mean sea level (MSL) at 13:38:42 IST (08:08:42 UTC), seconds after liftoff. However, radar data now suggests a far more dramatic descent than previously reported. The aircraft, operating in Ahmedabad’s elevation of approximately 189 feet MSL, is said to have descended 4,800 feet in 42 seconds, implying a starting altitude significantly higher than the 625 feet initially recorded. This discrepancy suggests either an error in early altitude reports or a misinterpretation of radar data, possibly referencing a descent relative to a higher reference point or a miscalibrated radar altimeter.
Assuming the 4,800-foot descent began shortly after the fuel cut-off at T+3s (13:38:42), the timeline aligns with the crash at T+32s (13:39:11). Extending the descent to 42 seconds may reflect radar data capturing the aircraft’s trajectory until ground impact or signal loss. A descent of 4,800 feet in 42 seconds equates to an average rate of approximately 6,857 feet per minute (fpm), far exceeding a controlled glide and indicating a near-vertical plunge. This rate suggests a stall or severe loss of lift, consistent with the dual-engine failure and the aircraft’s high drag configuration, as the landing gear remained deployed.
The radar data also confirms the aircraft’s ADS-B transponder signal was lost at 13:38:50 (T+11s), likely due to electrical disruptions following the Ram Air Turbine (RAT) deployment. Despite this, the cockpit retained partial power, as the RAT provided limited electrical and hydraulic support to critical systems, including flight controls and instrumentation. The flaps, set at 5 degrees for takeoff, remained deployed, as evidenced by wreckage photos showing extended slats and burn marks, indicating they were in position at impact.
Cockpit Conditions: Power, Flaps, and Silence
The AAIB report and wreckage analysis confirm that the cockpit had power during the descent, supported by the RAT’s activation at T+6s (13:38:47). The RAT powered essential flight controls, including flaperons and spoilers, but could not retract the landing gear, which remained down, increasing drag. The flaps’ deployed state, critical for low-speed lift, should have aided the pilots in maintaining some control, yet the rapid descent suggests insufficient lift or airspeed to counter the loss of thrust.
The cockpit voice recorder (CVR) captures a tense exchange at T+4s, with First Officer Clive Kunder, the pilot flying, asking Captain Sumeet Sabharwal, “Why did you cut off?” Sabharwal replied, “I didn’t.” A leaked 3-second audio clip, reportedly from the CVR, captures Kunder saying, “It feels wrong,” and alleging the autopilot acted contrary to pilot commands. This suggests a possible automation issue, such as a glitch in the Full Authority Digital Engine Control (FADEC) or flight management system (FMS), though the AAIB found no mechanical faults.
After the “MAYDAY” call at T+26s (13:39:05), the CVR records silence for the final 6 seconds until impact at T+32s (13:39:11). This silence is chilling, indicating either a cessation of communication as the pilots focused on recovery or a complete loss of situational awareness. The absence of audible warnings for the fuel switch movement, as noted in X posts, is puzzling, as the Boeing 787’s takeoff configuration warning system should have alerted the crew to any critical misconfiguration. The silence may also reflect the overwhelming nature of the cascade failure, with the HUD blinking off and electrical systems faltering, leaving the crew with minimal time to react at low altitude.
Theories Behind the Descent and Silence
The radar data and cockpit conditions point to several theories:
Automation Malfunction: Kunder’s leaked comment about the autopilot suggests a possible FADEC or FMS error, similar to a 2019 All Nippon Airways incident where a software glitch misinterpreted the aircraft’s status, shutting down an engine. The 2018 FAA bulletin on disengaged fuel switch locks, applicable to the 787, raises the possibility of a mechanical or software issue allowing unintended switch movement, though Air India reported no such defects since 2023.
Human Error Under Pressure: The CVR’s “Why did you cut off?” exchange implies Kunder believed Sabharwal moved the switches, though Sabharwal’s denial and the switches’ guarded design make accidental activation unlikely. The rapid descent and silence may indicate the pilots were overwhelmed, focusing on troubleshooting rather than communicating, as noted by aviation expert Keith Tonkin.
Electrical Cascade Failure: The RAT’s deployment and the HUD’s failure suggest an electrical overload or glitch disrupted critical systems, despite the cockpit retaining power. The silence could reflect the pilots’ struggle with degraded instrumentation, as the RAT’s limited capacity couldn’t sustain all avionics.
Deliberate Action: Speculation of intentional switch movement, as suggested by some U.S. officials, remains controversial. Kunder’s focus on the autopilot and Sabharwal’s reported final words, “I always trusted systems…,” argue against deliberate sabotage, as does the pilots’ attempt to restore fuel flow.
Contradictions and Investigation Challenges
The radar data’s claim of a 4,800-foot descent conflicts with the reported maximum altitude of 625 feet above MSL, as Ahmedabad’s elevation is only 189 feet. This suggests either a radar error, a misreported starting altitude, or a conflation with ground speed or distance metrics. The AAIB has not clarified this discrepancy, and the absence of the CVR’s full transcript limits understanding of the final silence. The lack of a cockpit video recorder, as highlighted by experts like John Nance, complicates identifying who, if anyone, manipulated the switches.
The silence following the “MAYDAY” call contrasts with the earlier vocal confusion, suggesting the pilots were either incapacitated by the crisis or focused on a last-ditch effort to glide the aircraft. The deployed flaps and partial power indicate they retained some control, yet the 6,857 fpm descent rate far exceeds the 787’s glide capability, ruling out a controlled descent. Simulations by Air India pilots confirmed that landing gear deployment and flap settings alone could not cause such a crash, pointing to the fuel cut-off as the primary trigger.
Implications for Aviation Safety
The catastrophic descent, despite power and deployed flaps, underscores vulnerabilities in the 787’s automation and human-machine interface. The leaked audio’s reference to autopilot misbehavior calls for scrutiny of the FMS and FADEC, especially given prior incidents. The silence in the CVR’s final seconds highlights the need for enhanced cockpit monitoring, such as video recorders, to capture pilot actions. The Indian Commercial Pilots’ Association and ALPA India have criticized the AAIB’s secrecy and media leaks, demanding transparency to counter speculation of pilot error.
Boeing and GE Aerospace face pressure to review the 787’s fuel switch mechanisms and automation systems, though no immediate safety directives have been issued. Air India’s fleet inspections found no defects, but the crash has raised questions about maintenance oversight, particularly regarding the 2018 FAA bulletin. The tragedy also renews calls for mandatory mental health screenings, despite no evidence of psychological distress in the pilots.
Conclusion
The radar data’s revelation of a 4,800-foot descent in 42 seconds, coupled with the cockpit’s retained power, deployed flaps, and final silence, paints a grim picture of Air India Flight 171’s last moments. The rapid plunge, triggered by the fuel cut-off, overwhelmed the experienced crew, leaving only seconds to react. Kunder’s leaked “It feels wrong” and autopilot concerns suggest a possible automation glitch, challenging the narrative of human error. As the AAIB, with NTSB and Boeing support, awaits the 2026 final report, the eerie silence following the “MAYDAY” call underscores the urgency of resolving this mystery. Flight 171’s legacy demands answers to ensure such a tragedy never recurs.
