Experts express their opinions on what caused Air India Boeing 787 crash

NEW DELHI, June 17: The Boeing 787-8 Dreamliner met with its first disaster in its 14-year history at Ahmedabad last week, killing all on board except one passenger and 33 others on the ground. Speculation about what caused the crash is swirling. All what we know for certain is the pilot's Mayday distress call, till the time the flight data recorder is examined. Every sign at the runway was normal.

If the pilot was able to tell the ATC at the critical moment, "Thrust not achieved... falling... Mayday! Mayday! Mayday!", he would as well have definitely stated the real cause instead, if he knew. Obviously, he was not aware of what exactly was preventing lift. It would also indicate the cockpit parametres were normal.

Besides, the CCTV and the video circulating on social media do not indicate any serious abnormalities in takeoff or descent.

Unlike what the common man thinks, modern airplanes don't plummet straight down even when both engines fail. The following is the second part of our series on some related questions raised by our readers and the answers given by experts for raising travellers' awareness about how we fly and the emergencies we may encounter.

IndiaTravelTimes: If both the engines fail, the aircraft (Boeing) should fall vertically, not in a gliding angle (as in the video). What do you say about that?

Expert: Not quite! If both engines fail, a Boeing aircraft—like most modern planes—is designed to glide rather than plummet straight down. Aircraft wings generate lift, allowing the plane to descend at a controlled angle rather than dropping vertically. Pilots are trained to manage this situation by maintaining optimal airspeed and angle of descent to maximize the aircraft’s glide range.

For example, a Boeing 747 can glide roughly 15 miles for every mile it descends. That gives pilots a chance to find a safe landing spot, whether it's a runway, a field, or even water. In short, even without engine power, aircraft don’t just drop like a rock—they use aerodynamics to stay controlled. Pretty fascinating, right?

Q: But in the Ethiopian crash the Boeing MAX fell in a vertical descent. How do you explain that?

A: An exception to the usual glide behaviour of aircraft is when other systems too fail like the MCAS in the case of Ethiopia's Boeing 737 MAX 8.

The Ethiopian Airlines Flight 302 crash was a tragic exception to the usual glide behaviour of aircraft. The Boeing 737 MAX 8 involved in the accident experienced a loss of control due to a faulty sensor triggering the Manoeuvring Characteristics Augmentation System (MCAS). This system repeatedly pushed the nose of the aircraft downward, despite the pilots' attempts to counteract it.

As a result, the plane entered a steep, uncontrollable dive shortly after takeoff, leading to its catastrophic impact. The force of the crash was so intense that both engines were found buried deep in the ground. This was not just a typical engine failure scenario but rather a failure of automated flight control systems, which led to a rapid descent instead of a controlled glide.

This crash, along with the earlier Lion Air Flight 610 accident, led to the worldwide grounding of the Boeing 737 MAX fleet and extensive investigations into its safety systems. It was a stark reminder of how critical software and sensor reliability are in modern aviation.

Q: In this context, how do you rate the survival chances of passengers of the Air India 787-8 Dreamliner if it had not hit the hostel building? You must have observed the Boeing was gliding and descending normally till it hit the building and then only crashed.

A: Yes. Good question. You are right. The survival chances of passengers aboard the Air India 787-8 Dreamliner would have been significantly higher if the aircraft had not collided with the hostel building.

As you said, reports and a video also indicate that the plane was gliding normally before impact, suggesting that it was still under some level of control.

However, the crash became catastrophic due to several factors:

The collision with the hostel building caused a violent impact, leading to structural failure and a massive fire.
The aircraft was carrying 1.25 lakh litres of fuel, which ignited upon impact, creating temperatures as high as 1,000°C, making survival extremely difficult.
The sole survivor, Vishwash Kumar Ramesh, was seated near an emergency exit, which allowed him to escape moments before the fire engulfed the wreckage.
If the aircraft had landed in an open area or even attempt a controlled emergency landing, the chances of survival would have been much much greater.

In previous aviation accidents where planes glided to emergency landings, many passengers survived.

Unfortunately, in this case, the collision with the building and subsequent fire reduced survival chances to Nil except one!

Q: If engine failure was the reason for "Thrust not achieved" Mayday call, both engines were facing problem. Otherwise he could manage with one engine. As you said, Boeing 787 can take off, climb and fly even with one engine. Did bird hit damage both engines? This is a one-in-a-billion chance like the Hudson mishap. Even then there should have been smoke coming from the engine. That is not in the video. There was no burnt bird debris found anywhere either. Your comments.

A: You're absolutely right that the Boeing 787-8 Dreamliner is designed to operate with one engine in case of failure. A dual-engine failure is extremely rare, which is why experts are still debating the exact cause of the crash.

Some aviation analysts suspect that a bird strike may have affected both engines, given the aircraft's sudden loss of thrust shortly after takeoff. However, as you pointed out, there was no visible smoke or burnt bird debris in the footage, which raises questions about whether a bird strike alone could have caused such a catastrophic failure.

Do you suspect something else?

Q. If due to engine or power failure the hydraulic system doesn't work, can the pilot still control the flaps and gears in Boeing 787-8 Dreamliner.

A: The Boeing 787-8 Dreamliner primarily relies on electrically powered systems rather than traditional hydraulic systems for many flight controls, including flaps and landing gear. However, in the event of a complete power failure, pilots may face significant challenges in controlling these components.

Flaps: The 787 uses electrically actuated flaps, meaning they do not depend on hydraulic power. If electrical power is lost, flap movement may be restricted, but backup systems could allow limited control.

Landing Gear: The landing gear is normally extended and retracted using electro-hydraulic actuators. In case of hydraulic failure, there are manual gear extension procedures, but retraction may not be possible.

Landing gear remained extended while flaps were prematurely retracted, possibly due to cascading system failures, which can sometimes lead to abnormal flight configurations.

Q: If flaps are not extended (as in the video), can you still take off/climb? Or, that led to the crash?

A: Flaps are crucial during takeoff because they increase lift, allowing the aircraft to climb efficiently. If flaps are not extended, the aircraft can still take off, but with compromised lift, making climb-out more difficult.

In this case, video footage and eyewitness accounts suggest that the flaps were fully retracted while the landing gear remained extended, which is an unstable configuration for ascent. Aviation experts speculate that this combination could have led to an aerodynamic stall, preventing the aircraft from gaining altitude.

Some theories suggest that the pilots may have accidentally retracted the flaps instead of the landing gear, which would have drastically reduced lift at a critical moment.

Q: What's your take on the latest revelation that RAT is down and extended as per a new video? Read with the retracted flap and extended gear positions.

A: The revelation that the Ram Air Turbine (RAT) was deployed adds a critical layer to the investigation. The RAT is a small emergency turbine that automatically extends when an aircraft experiences complete electrical power loss or severe hydraulic failure. Its presence suggests that the aircraft may have suffered a major systems failure, possibly affecting flight controls.

When combined with the retracted flaps and extended landing gear, this configuration is highly abnormal for takeoff. Flaps are essential for generating lift at lower speeds, and their premature retraction could have compromised climb performance, making it difficult for the aircraft to gain altitude. Meanwhile, extended landing gear increases drag, further reducing the aircraft’s ability to climb efficiently.

Experts analyzing the crash footage speculate that the RAT deployment may indicate a loss of primary electrical power, which could have affected key flight systems, including flap control and landing gear retraction. If the pilots were dealing with cascading failures, they may have been forced into emergency procedures that left the aircraft in an unstable configuration.

It is to be investigated whether the RAT deployment was a symptom of an electrical failure or a result of pilot intervention in response to an emergency. The black box data will determine.

ITT: Thank you. We would like to hear your take on the speculation of aviation fuel contamination or manipulation of the fuel lines as the cause of the Air India disaster in our next conversation.

(PART-III to follow)