My Research and Thoughts on the Air India 171 Tragedy

Preliminary Report-Accident involving Air India’s B787-8 aircraft bearing registration VT-ANB-at Ahmedabad on 12 June 2025

Introduction

The AI 171 crash was a tragic and complex aviation incident surrounded by conflicting reports and speculation. This blog post reviews available information, technical details, and pilot actions to provide a clear and balanced overview. It aims to help readers understand the event better and highlight the need for transparency and safety improvements in aviation.

Purpose of the investigation

I am an aviation enthusiast with a strong passion for understanding and following aviation news, incidents, and technical updates. Since 2020, I have been closely researching various aviation events, collecting information from articles, videos, official reports, and expert analyses to deepen my understanding.

When I learned about the AI 171 incident, I dedicated myself to studying all available material in detail. I took notes, cross-checked facts, and analyzed timelines and technical data to piece together a clearer picture of what might have happened.

This blog post is my effort to present a well-researched, clear, and logical summary of the incident based on publicly available information and technical reasoning. It aims to clarify inconsistencies, highlight important technical details, and encourage thoughtful discussion on aviation safety and accident investigations.

While I am not an aviation professional, my goal is to contribute to the conversation with transparency, curiosity, and respect for the facts, and to help others better understand this complex event.

Incident Overview

Brief description of flight, takeoff, crash:

Air India Express Flight AI 171 was operating with a Boeing 787 Dreamliner when it departed from Ahmedabad. The takeoff initially appeared normal, but shortly after rotation and liftoff, the aircraft encountered critical issues. Within seconds of becoming airborne, both engines unexpectedly lost power. Despite the pilots’ efforts to regain control, the aircraft, after climbing briefly to around 400 feet due to inertia, began to descend rapidly. The entire sequence from takeoff to impact lasted only about 32 seconds.Human impact (passengers, survivor, ground casualties):There were 242 people on board—passengers and crew. Tragically, almost all of them lost their lives, with only one known survivor. The crash site, near a hostel area, also resulted in casualties and injuries on the ground, adding to the scale of the tragedy.

Background Information

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Basic Flight Information: –

Pilot Information

Captain (Pilot Monitoring)	Sumeet Sabharwal (ATPL Holder)
First Officer (Pilot Flying)	Clive Kunder (CPL Holder)
Captain’s Experience	15600 hours (8600 hours in B787)
First Officer’s Experience	3400 flight hours (1100 hours in B787)

Timeline of Events

Key Timestamps:

• The entire flight from liftoff to impact lasted around 32 seconds.
• Rotation (VR): The nose was lifted, and the aircraft began liftoff.
• ~0–4 seconds after VR: Main landing gear left the ground.
• Immediately after liftoff (~30–40 ft): Both engines began losing power almost simultaneously.
• RAT Deployment (~70 ft): The Ram Air Turbine (RAT) deployed, indicating the aircraft had already lost engine-generated power very close to the ground.
• Peak Altitude (~400 ft): Due to initial momentum, the aircraft briefly climbed despite the engine failures.
• Final Descent (~32 seconds from takeoff): With no thrust and insufficient lift, the aircraft descended rapidly and crashed near a hostel area.

Sequence of Takeoff, Engine Failure, and Crash:

1. Takeoff Roll: Aircraft accelerated normally on the runway, reaching decision speed (V1) and then rotation speed (VR).
2. Liftoff: The nose lifted, and the aircraft left the ground as expected.
3. Engine Failure: Within seconds of liftoff, both engines unexpectedly failed. The pilots attempted to follow emergency procedures by cycling the fuel control switches to reignite engines.
4. RAT Activation: Loss of engine power triggered deployment of the RAT, supplying minimal emergency hydraulic and electrical power.
5. Climb and Inertia: The aircraft climbed briefly to approximately 400 feet due to momentum, but without engine thrust it could not sustain altitude.
6. Crash: The aircraft descended rapidly, impacted the ground within 32 seconds of liftoff, resulting in a catastrophic crash.

Critical Speeds During Takeoff

What are V‑speeds?

Speed	Meaning	What happens at this point
V1 – Decision Speed	The last speed on the runway where the crew must decide to abort or continue the takeoff.	After crossing V1, you are committed to fly even if an emergency occurs.
VR – Rotation Speed	The speed at which the pilot begins to pull back on the control column to raise the nose and start liftoff.	Nose starts to lift off the runway.
V2 – Takeoff Safety Speed	The minimum speed that must be achieved and maintained after takeoff with one engine inoperative	Ensures the aircraft can safely climb out even if one engine fails.

Observed Speeds and Timings for AI 171

• Rotation Speed (VR):
  The aircraft began to rotate at about 155 knots (noted in simulation recreations).
  The nose started to lift, and within about 4 seconds the main wheels left the ground—normal timing for a Boeing 787 near maximum takeoff weight.
• Maximum Recorded Speed:
  Shortly after liftoff, data shows the aircraft reached 175–180 knots, then began to lose speed as the engines failed.
• Time Between VR and Liftoff:
  For a normal Boeing 787 under MTOW, the time between VR and landing gear leaving the runway is around 4 seconds.
  AI 171 matched this timing, taking approximately 4 seconds from rotation to liftoff, which indicates that up to that point both engines were functioning normally.

Technical Analysis of Engine Failure

Dual Engine Failure Procedure (Boeing 787 Manual)

According to the Boeing 787 Flight Crew Training Manual:

• In the rare case of a dual engine failure, pilots are instructed to:
  1. Cut the fuel control switches off, then
  2. Turn them back on (recycle) to attempt an auto‑relight of the engines.
• This procedure is to be carried out regardless of airspeed or altitude because immediate action is required to restore thrust.

What happened on AI 171:

• The pilots followed this exact procedure.
• The left engine responded and ignited again after recycling, but the right engine failed to relight.
• This shows the crew was actively trying to recover the aircraft, not causing further harm.

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 RAT (Ram Air Turbine) Deployment Timing

• The RAT deploys automatically when both engines fail to provide emergency hydraulic and electrical power.
• Based on data and analysis from the passages:
  • The RAT deployed immediately after liftoff, around 70–100 feet altitude, which confirms that the engine failure occurred right at or just after liftoff—much earlier than some reports suggested (like 400–600 feet).
  • RAT deployment shows both engines were already out when the aircraft was still very low and climbing purely on inertia.

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TCMA (Thrust Control Malfunction Accommodation) and Known Engine Issues (Before Preliminary Report)

• The GEnx‑1B engines installed on Boeing 787s have a known fault called TCMA (Thrust Control Malfunction Accommodation).
• TCMA can trigger unintended engine shutdowns or fail to accommodate certain faults correctly.
• Similar failures have been investigated on other 787 flights (e.g., incidents in the US), but this was not addressed in the official report for AI 171.

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Service Bulletin / Bridge Ball Advisory Ignored

• A service bulletin was issued regarding a component called the bridge ball in the engine’s fuel system.
  • If not periodically replaced, it can lead to loss of thrust control.
• Additionally, the FAA issued an advisory in 2018 warning that fuel control switches on certain Boeing models (including B787/B717) could unintentionally move to “off” due to a faulty locking mechanism.
• Air India did not comply with this advisory because it was not legally mandatory, even though it was recommended for safety.

Takeoff Performance and Weight Factors

Overloading and Near‑MTOW Operations

• The aircraft was operating close to its Maximum Takeoff Weight (MTOW).
  • Approximate weight at departure: 2,13,401 Kgs, compared to the 787’s MTOW of around 2,18,183 Kgs.
• Operating near MTOW reduces takeoff performance and climb capability, leaving less margin if anything goes wrong.
• Industry insiders have suggested that overloading is sometimes under‑reported (passenger and cargo weight underestimated) to save costs, which further degrades performance.

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Longer Than Normal Runway Usage

• Performance charts from the passages indicate that the aircraft’s takeoff roll distance exceeded the normal limits:
  • The takeoff run crossed beyond the green and red reference lines on charts, into the yellow caution range.
• A longer-than-usual runway usage suggests:
  • Reduced thrust or
  • Higher-than-planned weight,
  • Or other factors affecting acceleration.

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Ahmedabad Runway Elevation

• Ahmedabad airport is around 200 feet above sea level.
• Higher elevation means lower air density, which slightly reduces engine thrust and aerodynamic lift compared to sea-level airports.
• While not extreme, combined with heavy weight, this elevation can contribute to longer takeoff runs and reduced climb performance.

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Charts and Performance Data

• In simulator recreations and performance data analysis:
  • Rotation speed (VR) and liftoff were consistent with heavy loading, requiring more runway and more time to become airborne.
  • Charts clearly showed the takeoff performance margin was tight, leaving little buffer for an unexpected event like a dual engine failure.

Maintenance and MEL Issues

CAC/Pack Failures and Cabin Pressure Warnings

• The Boeing 787 involved was not in perfect technical health even before departure.
• Out of four Cabin Air Compressor (CAC) units that supply air for pressurization and air‑conditioning, only one was fully functional:
  • Two CAC units were already inoperative.
  • The aircraft was released under the Minimum Equipment List (MEL), which legally allows operation with certain faults.
• Cabin pressure warnings had reportedly triggered earlier, meaning the remaining systems were under more stress.

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MEL Documentation Overload for Pilots

• Pilots received MEL documents several pages long before the flight, listing all deferred defects:
  • Items ranged from minor cabin issues (e.g., broken business‑class seats, water leaks) to critical systems (CAC failures, sensor issues).
  • These documents must be reviewed along with pre‑flight duties—in about 75 minutes—which is often not enough time to fully assess safety implications.
• Such information overload increases operational risk:
  • Important details might be overlooked.
  • Pilots are forced to rely on ground staff assurances that the aircraft is legally airworthy.

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Persistent Faults and Misuse of the MEL

• The airline’s culture reportedly allowed recurring technical faults to continue across multiple flights:
  • Faulty parts were sometimes swapped between aircraft to keep them flying longer than allowed.
  • Known issues were marked as MEL items rather than being permanently repaired, leading to chronic reliability problems.
• Pilots reported aircraft being dispatched with unresolved system faults, which creates a “Swiss cheese” scenario where multiple small failures can align and lead to disaster.

Operational Issues at Air India

Organisational Friction and Privatisation Impact

• After privatization and mergers, Air India’s engineering and maintenance departments have faced internal friction:
  • Disputes over ownership, pay structures, and responsibilities have affected workflow.
  • Maintenance decisions are often delayed or influenced by non‑technical management.
• This environment has created a culture where safety fixes are deferred, and operational priorities sometimes outweigh engineering caution.

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“Swiss Cheese” Model of Failures

• The crash highlights a systemic layering of small failures rather than one single cause:
  • Multiple technical issues (e.g., CAC failures, MEL items) combined with procedural oversights.
• This model underscores that no single factor caused the crash, but rather a chain of preventable weaknesses in the system.

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Poor Passenger Experience

• Passengers frequently encounter visible signs of poor maintenance and service on Air India flights:
  • Broken or malfunctioning seats (e.g., non‑reclining business‑class seats).
  • Inoperative call buttons and cabin systems.
  • Leaking water or malfunctioning in‑flight entertainment.
• These issues indicate underlying maintenance problems that go beyond passenger comfort and reflect deeper operational inefficiencies.

Inconsistencies in the Official Report

Engine Failure Timing vs. Physical Plausibility

• The official report claims the engine failure occurred after the aircraft reached certain speeds (e.g., after 180 knots or 42 seconds).
• However, technical analysis and simulation show this is physically implausible:
  • If the engine failed only after reaching 180 knots, the aircraft’s speed would initially continue rising briefly before dropping.
  • Evidence suggests the engine had already failed before the pilot operated the fuel cut switches.
• The timing described in the report conflicts with standard aerodynamics and pilot procedures, causing confusion and raising doubts about the accuracy of the report’s sequence.

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Photo Inconsistencies

• The report’s contains photos with notable discrepancies:
  • Some images show conflicting details about aircraft status (e.g., gear position, flap status).
  • These inconsistencies have not been adequately explained or addressed in the report.
• Such photographic issues add to concerns about the report’s overall reliability and thoroughness.

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FADEC Misspelling and Missing Signatures

• The report contains basic errors, such as misspelling critical terms like “FADEC” (Full Authority Digital Engine Control).
• There is a lack of official signatures, file numbers, and dates on the main report document.
• This absence of proper authorization and verification questions the legitimacy and completeness of the investigation.

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AAIB Statement: No Current Recommendations

• The Air Accident Investigation Bureau (AAIB) officially stated that at this stage of the investigation, there are no recommended actions for Boeing 787-8 and/or GE GEnx-1B engine operators or manufacturers.
• Despite this, issues related to these components have been noted but not formally addressed or linked as causes.
• This cautious stance raises questions about the depth and transparency of the ongoing investigation.

Media and Public Narrative

Mental Health Claims About the Pilot

• Some media outlets speculated that the captain was mentally disturbed due to the recent passing of his mother.
• These claims lacked any factual timestamps or official confirmation and often used vague terms like “immediately” without precise timing.
• Such narratives appear speculative and have not been substantiated by investigation data.

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US Media Leaks and Bias

• The preliminary investigation report was leaked primarily to US media outlets before official release.
• This leak included selective information that tended to shift blame onto the pilot rather than Boeing or systemic issues.
• Given Boeing’s significant economic footprint in the US, such bias might reflect underlying motivations.

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Economic Incentives to Blame Pilots

• Boeing contributes roughly US$97 billion annually to the US economy.
• The company employs over 150,000 direct workers and works with nearly 10,000 US suppliers.
• The US GDP is sensitive to disruption (0.4% quarterly).
• Insurance claims are easier and faster to settle if pilot error is accepted as the cause rather than manufacturing defects or airline negligence.
• This economic context suggests possible external pressures influencing the narrative around pilot blame.

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Flaps vs Gear Controversy

• A theory circulating online suggested that pilots might have accidentally retracted the flaps instead of the landing gear, causing loss of lift.
• Normally, pilots retract the landing gear at about 100 feet after takeoff; retracting flaps early would cause dangerous loss of lift and descent.
• However, this theory is highly questionable for several reasons:
  • Landing gear and flap handles are separate and positioned far apart in the Boeing 787 cockpit, making accidental flap retraction unlikely.
  • Flap retraction is a slow process (~18 seconds), giving pilots time to notice and correct any mistakes.
  • Boeing 787’s aircraft protection systems (like slat auto gap) prevent slat retraction at unsafe speeds and angles, guarding against lift loss.
  • Crash photos show slats were extended post-crash, indicating flaps/slats likely were not retracted.
  • Engines showed no malfunction, pointing to a lift-related issue but not flap retraction.
  • Even if the landing gear was left down mistakenly, the plane is certified to fly safely with gear down and one engine inoperative.
• Overall, flap retraction error as a cause is unlikely, and the real cause remains under official investigation.

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Black Box Handling and Location Data

8-Day Delay in Black Box Transport

• The aircraft’s black box (Flight Data Recorder) was kept in Ahmedabad for eight days after the crash.
• This was unusual because the black box should have been transported promptly to Delhi for detailed analysis.
• This delay raised concerns about transparency and procedural adherence during the investigation.

Emergency Locator Transmitter (ELT) Failure

• The ELT, which automatically activates to provide the aircraft’s location after a crash, did not activate during this incident.
• The failure of the ELT made locating the crash site significantly more difficult, especially in areas like forests or oceans.
• This critical failure was barely addressed in the official report, raising further questions about equipment reliability and investigation completeness.

Investigation Process and Accountability

 Preliminary Report Deadlines and Purpose

• According to international standards (Section 7), the preliminary crash report is due within 30 days after the incident.
• For AI 171, the report was completed on July 11 and publicly released on July 12.
• The purpose of this report is to present facts and data, not to assign blame or make prevention recommendations.
• However, the report was criticized for lacking detail, clarity, and technical precision, leaving many questions unanswered.

Historical Pattern of Blaming Pilots

• Indian accident investigations often have a tendency to place the blame on pilots, even when contradictory evidence exists.
• This approach can sidestep deeper issues like maintenance lapses, systemic failures, or regulatory shortcomings.
• Past investigations have shown missing or deleted critical data, such as Cockpit Voice Recorder (CVR) recordings, further clouding transparency.
• The investigation culture appears to favor quick closure by blaming human error, rather than pursuing root causes.

Systemic Issues and Industry Culture

• Boeing structural concerns have been raised by whistleblower engineers alleging defects like structural gaps and improperly fused joints in Boeing 787 aircraft.
• Despite congressional hearings, audits officially denied these concerns, highlighting potential conflicts of interest and insufficient oversight.
• This echoes the earlier Boeing 737 Max safety crisis, where design flaws, inadequate training, and software issues led to catastrophic crashes.
• The regulatory environment often appears to protect manufacturers (Boeing), airlines (Air India), and suppliers (engine makers) rather than prioritize safety and accountability.
• Insurance and economic factors incentivize assigning blame to pilots instead of addressing systemic faults.

Pilot Challenges During Engine Failure

• Engine failure during or shortly after takeoff is one of the most stressful and time-critical emergencies pilots can face.
• Pilots must react within seconds under extreme pressure to follow memory items and emergency procedures.
• Common pilot errors under stress include delayed rotation, retracting the wrong systems (landing gear vs flaps), or cutting off the wrong engine.
• A notable example is GoAir Flight 338 (June 21, 2017), where after a bird strike, pilots mistakenly shut down the working engine, resulting in dual-engine failure at 3300 ft. Fortunately, a safe emergency landing was made.
• This incident underscores the difficulty pilots face in managing multiple failures simultaneously.

Professional Behavior of AI 171 Crew

• Despite the overwhelming emergency, AI 171’s pilots demonstrated calm professionalism.
• They attempted to relight the engines by recycling the fuel switches, consistent with Boeing 787 manuals.
• The captain, with over 15,000 flight hours and experience as a trainer, made deliberate efforts to control the aircraft.
• The calm mayday call and nose-up input before the crash indicate the crew were focused on minimizing damage and saving lives, not negligent or reckless.
• These actions strongly counter the narrative that pilot error or mental instability caused the accident.

Conclusion

Summary of Findings

• The AI 171 crash was a tragic event marked by a rare dual-engine failure shortly after takeoff, leading to the loss of almost all lives on board and casualties on the ground.
• Evidence indicates the pilots followed emergency procedures professionally and made every effort to control the aircraft, contradicting narratives blaming pilot error or mental health issues.
• The investigation report lacked clarity, detailed technical analysis, and transparency, with inconsistencies in timelines, missing official signatures, and unexplained handling of crucial evidence such as the black box and ELT failure.
• Systemic issues including Air India’s operational shortcomings, poor maintenance practices, ignored FAA advisories, and Boeing’s ongoing safety concerns contributed to the incident’s complexity.
• Economic and regulatory pressures appear to influence the public narrative, with incentives to shift blame towards pilots rather than manufacturers or airlines.
• The flap versus landing gear retraction controversy highlights misunderstandings about cockpit design and aircraft protections, further emphasizing the need for accurate technical communication.
• Overall, the crash underscores critical vulnerabilities in aviation safety culture, investigation integrity, and regulatory oversight.

Call for Transparency and Systemic Change

• There is an urgent need for independent, thorough, and transparent investigations free from external influence to establish the true causes of the crash.
• Aviation authorities must prioritize systemic reforms, including improved maintenance standards, stricter compliance with safety advisories, and enhanced pilot training under realistic conditions.
• Manufacturers like Boeing must be held accountable for addressing known design and software issues and ensuring robust safety assurances.
• Media and public discourse should be informed by technical facts rather than speculation or economic interests that distort the truth.
• Ultimately, safeguarding passenger lives and restoring public trust demands a holistic approach that addresses both human and technical factors, supported by a culture of openness and continuous learning.

References and Sources

• Boeing 787 Flight Crew Training Manual – Dual Engine Failure Procedures.
• FAA Advisory (2018) on fuel control switches and locking mechanisms for Boeing aircraft (including B787 series).
• Various publicly available accident investigation reports (preliminary)
• News articles, and independent pilot analyses discussed in online forums and video content.
• Youtube Videos (Flying Beast, Captain Steeeve, Joe Costanze, Dhruv Rathee, Garybpilot and many more.
• Personal simulation tests and notes from reviewing speed data, timestamps, and video footage of the incident.
• Use of AI tools (ChatGPT, Gemini, Perplexity and many more)

JAI SIYA RAM🙏 🙏 🙏