One of the pilots of Air India 171 seemed to suggest the aircraft was having engine issues in a frantic Mayday call as the Boeing 787-8 descended toward a medical school apartment building 20 seconds after taking off from Ahmedabad Airport Thursday. “Thrust not achieved … falling … Mayday! Mayday! Mayday!” the pilot was recorded as saying in an exchange released on Sunday. The tower tape added fresh detail to the rampant speculation about the cause of the crash, which killed 241 of 242 people onboard the Dreamliner for the 10-hour flight to London’s Gatwick Airport. The lone survivor walked away from the crash mostly uninjured but remains in a local hospital.
The flight data recorder has been recovered from the aircraft but the cockpit voice recorder has not. Until the data is downloaded from those devices, speculation on the cause of the crash has centered on a poor quality cellphone video that some believe shows the flaps retracted. There are also those who believe the video shows the ram air turbine (RAT) deployed, indicating a loss of electrical power. The FDR, assuming the data is recoverable, will be able to confirm whether any of those conditions were present when the plane initially climbed to 400 feet AGL, pitched up and then lost altitude at a sink rate of about 475 feet per minute. In addition to the casualties on the plane, at least 29 people on the ground were also killed.
Could I really be the only person on here or Facebook or elsewhere who has pointed out the trajectory of this aircraft with its long, slender, elegant wings resembles a classic “ “Lifting off thanks to ground effect, climbing out of ground effect at a wingspan AGL , and thus settling back in” accident whether that airspeed deficit is due to power loss or no flaps or something else. In panic mode that ESL radio caller may have meant to say “ no lift” rather than “no thrust”.
In today’s english speaking edition of “were the deck chairs properly aligned on the titanic” we can clearly see how that radio call mattered to all those lost lives in India.
Captain obvious at your service.
Good note, but recognize the effect diminishes with height - it is not a sudden cutoff.
It is a clue as to what the crew were grasping.
Hopefully the CVR will be found with useable information on it - a fire smouldering for a long time would not be good.
What I studied was that ground effect was a consideration within 1/2 of the wingspan of altitude. This aircraft climbed 400 feet (and the climb looked smooth for a heavy aircraft on a hot day), so I discount that theory. Also, the mayday call was “lost power - no thrust” – this was reported last evening and is somewhat at variance with this article.
If they shot a fully loaded 787 down the runway to rotation speed, then “thrust was achieved”. I can only guess that the pilot misinterpreted the situation and was still confused when the plane settled downward.
I’m astonished from armchair quarterbacks sans 8,000 hours of flight time.
Speaking of experience, I’m never astonished that these so-called accidents happen primarily with foreign air carriers like India, Malaysia , Korea, Ethiopia and Indonesia.
That might be because the US has a small population compared to the rest of the world and a whole lot fewer airplanes/airlines. The world does not end at the US border.
Not ground effect. the aircraft would not have climbed away at all and just floated along till the airspeed dropped below stall.
Facts:- The pilot not flying declared a loss of thrust in his mayday. The RAT DID deploy as the noise was audible and it was clearly visible in some of the videos. The only speculation is why would two engines simultaneously suffer the same thrust roll-back? The primary answer is obviously loss of fuel flow, either from the airframe, or within the engines, but why?
Inadequate knowledge alert!
‘Ground effect’ on drag and lift diminishes quickly with altitude AGL, there is no cutoff as one poster thinks but the amount quickly becomes irrelevantly small.
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petebutt43:
You aren’t making sense.
You should integrate all factors, including trading speed for altitude.
RAT deployment is very interesting.
The FDR recording if useable should show at what point thrust declined.
I note that apparently the airplane used all of the runway, if observed dust was off the end so airplane quite low. (But normal obstacle clearance requirements with loss of thrust of one engine only specify 35 feet above end of runway, though in this case there was an obstacle on or near the flight path - the building the airplane hit.
One SOP is to make an acceleration check at 80 knot or so, perhaps more in an overspeed takeoff - has expected distance down runway been achieved? That requires an estimate of that distance for the particular takeoff.
(‘Feel’ of performance many not be accurate. Testing of B737-200C at 2500 feet high Edmonton International at high weight, hot day showed normal performance while crews felt airplane was not performing correctly.
Have you checked those assertions against any actual data? Smaller population does not correlate with fewer aircraft or airliners.
There is one airport in Alaska with 500 seaplane slips. There’s a waiting list. How many seaplanes in your baseline densely-populated nation? A dozen? Major US airlines operate thousands of aircraft, some overseas, but I bet if you find the actual numbers you will find that US airlines still eclipse China, India, or any other country in terms of number of aircraft, enplanements, seat-miles, operations, number of qualified pilots, or just about any metric you can dream up.
They had limited speed, so how are they going to trade for altitude.I think it is you that has a lack of knowledge.
Exactly what I wrote!
Neglecting to extend flaps, trying to takeoff on wrong shorter runway, … happen in the US. Not often but they do.
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Target climb speed is above stall speed, so there is some ability to trade speed for altitude, but eventually stall occurs or an obstruction may intervene.
You don’t know until FDR data is successfully retrieved.
Decades ago a poohbah of Transport Canada was persuaded to go to Yellowknife to look at seaplane operations. He came back raving about the number of float planes on the lake, remarking that a large proportion were one-airplane operations. Changed his mind on helping operators and on regulations.
At the Otter 50th show by Viking at YYJ I met a couple who had just flown down from AK to attend, they were busy providing services prior to the trip.
But the rest of the world has different standards, and techniques, and cultures.
That plays a role especially when things do not go 100% right on a flight.
Well, let’s wait and see if that was the case or not.
People who DO fly the 777/787 have been online saying that the aircraft did not really need 5% flaps to stay in the air after takeoff (under these conditions of the flight).
“It is a clue as to what the crew were grasping.” At that moment anyway, RAT deploying is very interesting.
Investigators should examine the ground that people think the airplane was close to at end of takeoff roll (dust observed), debris ingestion is another think to consider but FDR data if obtained would pinpoint where thrust was lost and might give clues as to why. (Engine parameters and controls.)
Neglecting to extend flaps, trying to takeoff on wrong shorter runway, … happen in the US. Not often but they do.
The Daily Mail of 19Jun25 reports that both of the ‘black bozes’ have been found.
However, I read elsewhere that a video recorder had been found.
The paper reports that the right engine had been replaced in March.
One more Fact:- The u/c WAS selected up, but didn’t complete the sequence. The first action on selecting up the bogie is tilted hydraulically nose down, which the bogies clearly are on the video. The sequence was obviously interrupted then as the U/c doors didn’t open, which would have been the next action.
The recorders on a 787 are Combi-recorders, which record BOTH VCR and FDR data, so you only need to find one.
Leading edge flaps are usually very important to stability when airplane pitched up, until speed increases.
Early in DC9-10 operations in the US, one crashed because it was pitched up aggressively (-10 did not have LE flaps).
FTR, subsequent examination of images suggests flaps were extended at a low setting such as 5 (typically LE slats are out at any TE flap extension value), and that full length of runway was used. I was simply listing potentials - days ago.
Your statement does not include speed those pontificators were thinking of - there is a reason flap extension is used during takeoff,
Instructive in possibilities is B737 at Bristol England on 04Mar25.
Autothrottle disengaged during takeoff roll so crew set thrust manually but too low.
Only achieved 10 feet over end of runway instead of normal 35 feet or more.
Good information thankyou.
What I found most significant was from an interview with the sole surviving passenger. He stated that his first indication of a problem was that the cabin lights started flickering and changing colours. That stands out as an electrical system problem. Hasn’t anyone else seen that interview? That is a big clue.
And there is currently a tit-for-tat India is having with a border country, too.
the higher quality video gave a plethora of information:- The flaps WERE extended (slats can be seen extended); The U/c WAS selected up (the bogies were in the nose down position which is the first item in retraction sequence); The RAT was deployed (clearly visible n the higher quality vid + the distinctive noise and witness statement from survivor). Some form of dual engine thrust roll-back occurred. Hydraulic power was interrupted just after selecting gear up (all four pumps are electrically driven). The RAT would supply electrical power to only one hydraulic pump, which prioritises flight controls.
Good, increases chance that data survived.
Crash recorders cannot withstand all events, prolonged fire smouldering eliminated data from CVR of PW314.
Maintenance of recorder systems has been a problem before some crashes.
One tactic with dual mode is to locate one in front of aircraft, nose often survives because it tends to be strong (as in UA232 for example.)
Good to know, higher quality video and onsite wreckage photos are useful.
The FACTS with no spin or speculation:- Flaps and slat WERE extended: U/C WAS selected up (the bogies had translated to nose down, but u/c doors did not open). The RAT did deploy (clearly visible + distinctive noise): Some form of thrust roll-back occurred on both engines simultaneously (enough for all the generators to drop off line)
Some form of thrust roll back is the correct answer. I was told by a former 787 pilot that the thrust levers are not physically connected to the engine fuel controls. In simplistic terms the thrust levers “communicate” electronically with the fuel controls. There was a failure of that system. Likely following a major electrical system failure.
I mean, the “tit-for-tat” has been going on since 1947 off and on, and even before that when Pakistan was still part of India. Terrorism is always a possibility until it is ruled out by finding the actual cause. But has anyone seen a reason to suspect foul play??? Been on the rise in recent decades, sure, but still, most incidents, by far, turn out to be accidents, not crimes…
Chicken and egg problem:- was the thrust roll-back caused by the electrical failure or was the electrical failure due to the engine thrust roll-backs?
Some form of thrust roll back is the correct answer. I was told by a former 787 pilot that the thrust levers are not physically connected to the engine fuel controls. In simplistic terms the thrust levers “communicate” electronically with the fuel controls - OK that much is obvious.
“There was a failure of that system. Likely following a major electrical system failure.” is PURE speculation.
PURE speculation. Thrust roll-back yes, anything other than facts gleaned from the videos is speculation:- Flaps down (slats extended - vids and photos), U/c selected up (bogies nose down), RAT extended (clearly visible and distinctive noise on videos), Thrust roll-back / double engine failure ( RPM to idle or low speed, or complete shut-down, not obvious either way)