July 13, 2025, 12:19:00 GMT
permalink Post: 11921280
One question, from looking at my own timeline.
It appears that we went from a position of loss of both engines (i.e. trigger for auto RAT deployment) to RAT supplying power within between 3 and 5 seconds.
Does anyone know:
1. How long the RAT takes to deploy and generate power from point of trigger?
2. Is it the act of engine loss (from fuel shutoff) that is the auto trigger, or the sub idle power that is the trigger (in which case this would take around 1 of these seconds)?
Also, at peak IAS of 180kts, presumably less by the time RAT is actually deployed, combined with the RAT drag and a minimum speed of 130kts for (reliable) RAT performance, I assume that the RAT would not in fact have provided power for all that long in truth?
It appears that we went from a position of loss of both engines (i.e. trigger for auto RAT deployment) to RAT supplying power within between 3 and 5 seconds.
Does anyone know:
1. How long the RAT takes to deploy and generate power from point of trigger?
2. Is it the act of engine loss (from fuel shutoff) that is the auto trigger, or the sub idle power that is the trigger (in which case this would take around 1 of these seconds)?
Also, at peak IAS of 180kts, presumably less by the time RAT is actually deployed, combined with the RAT drag and a minimum speed of 130kts for (reliable) RAT performance, I assume that the RAT would not in fact have provided power for all that long in truth?
July 13, 2025, 13:29:00 GMT
permalink Post: 11921325
This is excellent, thank you. It has helped me to crystallise a thought about the length of time the switches were at cut off.
10 seconds is a long time in a life threatening situation (like most clich\xe9s, the cinematic trope of time slowing down only reflects people's real experiences, mine included). Reaction times to completely unexpected events can be in the order of 3-5 seconds, but I find it hard to think that it would have taken any pilot as much as 5-7 seconds to set the first switch back to run. It's not something that anyone trying to save the aircraft is going to take time to consider.
Possible explanations for the length of time are a physical altercation - but if that was so, then why did the switches then stay at run? We will be none the wiser on that, at least until the next report. Another, perhaps more likely possibility is that the switch movement itself was unnoticed by at least one of the pilots, and was not noticed until its effects took hold a couple of seconds later (my phrasing here is intended to leave open the question of how the switch moved, or was moved). Combined with the startle reaction time, this would start to explain a 10 second delay. So I expect the CVR comments are towards the later end of the possible range indicated in the excellent diagram.
10 seconds is a long time in a life threatening situation (like most clich\xe9s, the cinematic trope of time slowing down only reflects people's real experiences, mine included). Reaction times to completely unexpected events can be in the order of 3-5 seconds, but I find it hard to think that it would have taken any pilot as much as 5-7 seconds to set the first switch back to run. It's not something that anyone trying to save the aircraft is going to take time to consider.
Possible explanations for the length of time are a physical altercation - but if that was so, then why did the switches then stay at run? We will be none the wiser on that, at least until the next report. Another, perhaps more likely possibility is that the switch movement itself was unnoticed by at least one of the pilots, and was not noticed until its effects took hold a couple of seconds later (my phrasing here is intended to leave open the question of how the switch moved, or was moved). Combined with the startle reaction time, this would start to explain a 10 second delay. So I expect the CVR comments are towards the later end of the possible range indicated in the excellent diagram.
If powered by the RAT or APU would that introduce a time delay before you an can effectively put them back to Run?
July 13, 2025, 15:22:00 GMT
permalink Post: 11921391
The graph based on the preliminary timeline would indicate 2-3 seconds to establish the RAT power. Having used RATs in the sim and on test flights on two types, that\x92s seems correct. It\x92s very quick and, if the switches were cutoff on the runway, no way would the plane achieved that flight path, probablt overrun the runway.
July 13, 2025, 17:40:00 GMT
permalink Post: 11921477
Hi,
I have a couple of questions. Forgive me for being late into this thread if any of them is already discussed:
1) I just read this in a Boeing manual:
2) Looking at the incident timeline, one of the pilots takes corrective action to reswitch to RUN position 10 seconds after maximum air speed is reached and 5 seconds after RAT is deployed. Is this normal?
It's not clear however that whether their conversation is after or before the RAT is deployed.
(No visual or auditory cues in the cockpit for a critical fuel switch action? Not hearing the engines shutting down?)
3) The same pilot that turns on Engine 1's fuel switch, turns on Engine 2's switch 4 whole seconds later. Why not consecutively, right one after the other, just like they were turned off one second apart?
If only he had done so the second engine might have recovered in time as well.
4) This aircraft's TCM has been replaced in 2019 and 2023, not related to a fuel switch issue. And there had been no fuel switch defect reports since 2023. One begs to ask if there had been a fuel switch defect report back in 2023 and what was the nature of it?
Are TCM's replaced as a whole, including the switches, twice? If so, why wouldn't they install a TCM version at least in 2023 with redesigned switches (w/ enhanced locking mechanism) mentioned in the FAA SAIB? Have they installed old/used TCM's manufactured prior to 2018 SAIB?
Please note that the RH and LH GE engines of the aircraft were only installed in March 2025 and May 2025 respectively, but they were used and dating from 2013 and 2012. Is this normal for a 12 year old Boeing aircraft to change so many mission critical components?
Electronic parts somehow, but how durable are those GE engines?
Thanks,
C.A.
I have a couple of questions. Forgive me for being late into this thread if any of them is already discussed:
1) I just read this in a Boeing manual:
The fuel control switches send signals to open or close fuel valves to operate or shutdown the engines.
- They send signals to the remote data concentrators (RDC) and the spar valve start switch relays.
- The spar valve start switch relays use these signals to control the spar valve and the high pressure shut off valve (HPSOV) in the fuel metering unit (FMU).
- The RDCs send the signals to the common data network (CDN) and then to the electronic engine control (EEC) to operate the FMU fuel valves (FMV and HPSOV).
The fuel control switches have 2 positions:
- RUN
- CUTOFF.
You must pull the switch out of a detent to select a position.
There seems to be RDC's (remote data concentrators) and CDN (common data network) between those fuel switches and the fuel valves. Is there any possibility that there may have been an electronic control module or sensor fault to generate such a signal rather than mechanical switch movements?
- They send signals to the remote data concentrators (RDC) and the spar valve start switch relays.
- The spar valve start switch relays use these signals to control the spar valve and the high pressure shut off valve (HPSOV) in the fuel metering unit (FMU).
- The RDCs send the signals to the common data network (CDN) and then to the electronic engine control (EEC) to operate the FMU fuel valves (FMV and HPSOV).
The fuel control switches have 2 positions:
- RUN
- CUTOFF.
You must pull the switch out of a detent to select a position.
2) Looking at the incident timeline, one of the pilots takes corrective action to reswitch to RUN position 10 seconds after maximum air speed is reached and 5 seconds after RAT is deployed. Is this normal?
It's not clear however that whether their conversation is after or before the RAT is deployed.
(No visual or auditory cues in the cockpit for a critical fuel switch action? Not hearing the engines shutting down?)
3) The same pilot that turns on Engine 1's fuel switch, turns on Engine 2's switch 4 whole seconds later. Why not consecutively, right one after the other, just like they were turned off one second apart?
If only he had done so the second engine might have recovered in time as well.
4) This aircraft's TCM has been replaced in 2019 and 2023, not related to a fuel switch issue. And there had been no fuel switch defect reports since 2023. One begs to ask if there had been a fuel switch defect report back in 2023 and what was the nature of it?
Are TCM's replaced as a whole, including the switches, twice? If so, why wouldn't they install a TCM version at least in 2023 with redesigned switches (w/ enhanced locking mechanism) mentioned in the FAA SAIB? Have they installed old/used TCM's manufactured prior to 2018 SAIB?
Please note that the RH and LH GE engines of the aircraft were only installed in March 2025 and May 2025 respectively, but they were used and dating from 2013 and 2012. Is this normal for a 12 year old Boeing aircraft to change so many mission critical components?
Electronic parts somehow, but how durable are those GE engines?
Thanks,
C.A.
When reading any of the data when it comes out, pay some attention to the sampling rate of the data being provided, it is quite possible to make erroneous assumptions where that is not taken into consideration. The data buses used to get data from the aircraft system to the recorder, and the recorders themselves use sequential sentences, and varyious rates.
IMHO.
July 13, 2025, 17:54:00 GMT
permalink Post: 11921488
The event shows that it's really imperative to relight the engines as quickly as possible.
The preliminary report says it took about 5 seconds for the engines to spool down to idle. 14 CFR \xa7 33.73 - Power or thrust response requires a jet engine to reach 95% thrust from stabilized flight idle in not over 5 seconds. So with a sufficiently quick reaction, flipping the switches back after 5 seconds, they could've been back in business by the time they actually flipped the switches back.
So it's not "flip the switches 3 seconds after liftoff and you're unrecoverable"; to be unrecoverable, there must also be sufficient time for the engines to spool down enough.
Don't ask, "why did you cut the engines", flip them back on. Go for the E in PACE.
The preliminary report says it took about 5 seconds for the engines to spool down to idle. 14 CFR \xa7 33.73 - Power or thrust response requires a jet engine to reach 95% thrust from stabilized flight idle in not over 5 seconds. So with a sufficiently quick reaction, flipping the switches back after 5 seconds, they could've been back in business by the time they actually flipped the switches back.
So it's not "flip the switches 3 seconds after liftoff and you're unrecoverable"; to be unrecoverable, there must also be sufficient time for the engines to spool down enough.
Don't ask, "why did you cut the engines", flip them back on. Go for the E in PACE.
It's possible from the timeline in the report that this statement was made at the same time (or even after) they were moved back to RUN. The report is ambiguous on this unfortunately...!
Re: spool down to idle, that is interesting and passed me by - the report certainly does imply it took 5 seconds, which is at odds at an earlier post from (I believe) tdracer , who said this would take 1, maximum 2, seconds.
However when I read it again, it's again ambiguous - the 5 seconds is when the RAT started supplying power, but this isn't clear and unequivocal that engine went below idle at the same time in the wording, although definitely heavily implied.
July 13, 2025, 18:03:00 GMT
permalink Post: 11921493
Electrical effects of engine rollback
As I understand it from previous discussions, without the APU, all electrical power except for that DC power provided by battery to essential systems would have been lost.
With the copilot as PF, would he have lost his instrument displays? If so, possibly additional startle effect and workload for him.
Why did the ADS-B information keep going on for so long? My understanding from previous threads was that loss of ADS-B was considered an indication of loss of electrical power.
What else would be expected with loss of power?
Some general speculation: I find it hard to understand the long delay from what must have been the onset of obvious issues to the time the first engine is set to "RUN". I wonder if much more cockpit dialog intervened, e.g. PF requesting PM to turn the fuel switches back on (since he had his hands full), and eventually operating the switches himself, with the delay and time gap between the two switches being turned to "RUN" being attributable to being preoccupied with flying the aircraft under trying conditions.
July 13, 2025, 18:39:00 GMT
permalink Post: 11921522
I would like to raise a subject that I don't believe has been discussed here since the Preliminary Report was published, namely what happened to the aircraft's electrical systems as a consequence of the dual engine rollback and thereafter (RAT deployment, partial engine recovery, etc.). Apologies if I've missed posts on this topic here, but I have tried to review all of this thread quickly after previously reading most of it in detail.
As I understand it from previous discussions, without the APU, all electrical power except for that DC power provided by battery to essential systems would have been lost.
With the copilot as PF, would he have lost his instrument displays? If so, possibly additional startle effect and workload for him.
Why did the ADS-B information keep going on for so long? My understanding from previous threads was that loss of ADS-B was considered an indication of loss of electrical power.
What else would be expected with loss of power?
Some general speculation: I find it hard to understand the long delay from what must have been the onset of obvious issues to the time the first engine is set to "RUN". I wonder if much more cockpit dialog intervened, e.g. PF requesting PM to turn the fuel switches back on (since he had his hands full), and eventually operating the switches himself, with the delay and time gap between the two switches being turned to "RUN" being attributable to being preoccupied with flying the aircraft under trying conditions.
As I understand it from previous discussions, without the APU, all electrical power except for that DC power provided by battery to essential systems would have been lost.
With the copilot as PF, would he have lost his instrument displays? If so, possibly additional startle effect and workload for him.
Why did the ADS-B information keep going on for so long? My understanding from previous threads was that loss of ADS-B was considered an indication of loss of electrical power.
What else would be expected with loss of power?
Some general speculation: I find it hard to understand the long delay from what must have been the onset of obvious issues to the time the first engine is set to "RUN". I wonder if much more cockpit dialog intervened, e.g. PF requesting PM to turn the fuel switches back on (since he had his hands full), and eventually operating the switches himself, with the delay and time gap between the two switches being turned to "RUN" being attributable to being preoccupied with flying the aircraft under trying conditions.
There seems to be a period around second 12/13 post V1 where engines are (or should) be likely below idle, but prior to RAT power generation.
Note that the report explicitly states the RAT started providing hydraulic power 5 seconds after engine shutdown commenced. It doesn't reference electrical power. So we don't know whether this was at the same time - others may clarify re: RAT operation.
But either way, it would appear there would be a gap in power (which, incidentally, would tie in with the survivor commentary). But yet ADS data continued.
If in fact there was a momentary loss of power then that would contribute heavily to the startle and "delay" in refiring (although comments here make me think there wasn't really such a delay anyway).
(And incidentally would make what appears to be a really rather valiant attempt to save the aircraft even more impressive)
July 13, 2025, 19:06:00 GMT
permalink Post: 11921541
These for me are very interesting questions.
There seems to be a period around second 12/13 post V1 where engines are (or should) be likely below idle, but prior to RAT power generation.
Note that the report explicitly states the RAT started providing hydraulic power 5 seconds after engine shutdown commenced. It doesn't reference electrical power. So we don't know whether this was at the same time - others may clarify re: RAT operation.
There seems to be a period around second 12/13 post V1 where engines are (or should) be likely below idle, but prior to RAT power generation.
Note that the report explicitly states the RAT started providing hydraulic power 5 seconds after engine shutdown commenced. It doesn't reference electrical power. So we don't know whether this was at the same time - others may clarify re: RAT operation.
If memory serves me right on the 777 the electrical output capacity of the APU is about 8-10 times the output capacity of the RAT.
It will likely be even more on the 787.
July 13, 2025, 19:10:00 GMT
permalink Post: 11921547
I assume this means that the APU was not operational until this point?
July 13, 2025, 19:16:00 GMT
permalink Post: 11921552
I don\x92t know if it started to open or was registered open at 8 seconds.
July 13, 2025, 19:18:00 GMT
permalink Post: 11921555
The APU needs air to operate. The inlet provides that air.
July 13, 2025, 19:20:00 GMT
permalink Post: 11921557
I believe the APU can take quite a while to start, certainly more than 30 seconds. The APU inlet door in the wreckage is open but it's not clear if it is fully open or perhaps closed a little with the loss of whatever power is used to drive the actuator. Electrical or hydraulic? I have seen other 787 APU inlet door photos showing what seems to be a wider aperture but that was on an aircraft on the ground.
July 13, 2025, 19:27:00 GMT
permalink Post: 11921563
So this brings me back to my original observation (and that of another poster) - it would appear that there was a time period of at least 2 seconds, and potentially longer depending upon RAT electrical power, where the aircraft lost some (?) or all (?) electrical power, which hasn't really been discussed.
This would definitely contribute to recovery challenges (albeit slightly tangential to root cause discussion).
(And, strangely, ADS data appeared to continue during the period this would have occurred)
July 13, 2025, 19:37:00 GMT
permalink Post: 11921569
Thanks to you both.
So this brings me back to my original observation (and that of another poster) - it would appear that there was a time period of at least 2 seconds, and potentially longer depending upon RAT electrical power, where the aircraft lost some (?) or all (?) electrical power, which hasn't really been discussed.
This would definitely contribute to recovery challenges (albeit slightly tangential to root cause discussion).
(And, strangely, ADS data appeared to continue during the period this would have occurred)
So this brings me back to my original observation (and that of another poster) - it would appear that there was a time period of at least 2 seconds, and potentially longer depending upon RAT electrical power, where the aircraft lost some (?) or all (?) electrical power, which hasn't really been discussed.
This would definitely contribute to recovery challenges (albeit slightly tangential to root cause discussion).
(And, strangely, ADS data appeared to continue during the period this would have occurred)
Without the APU, would there have been sufficient power to restart even one engine, never mind two?
Could this be why the delay between the first and second switches being moved to RUN?
Does it also mean that in reality the 10 seconds between OFF and RUN is immaterial as there was insufficient electrical power to start the engines anyway?
July 13, 2025, 20:36:00 GMT
permalink Post: 11921626
From the point that the fuel cutoffs were switched back to run, the primary (perhaps only) relevant issues were time and altitude. The left engine was relit and recovering on it's own but the right would probably have needed cranking as it appears to have had a hung start because it was spooled down too far and the airspeed was too low. However, I'm pretty sure that even if the APU had already been running at takeoff, they still would have needed at least another 30 seconds if not longer for full thrust. Also, there was nowhere near enough time for the APU to start and come online here.
Last edited by Mrshed; 13th July 2025 at 20:49 .
July 13, 2025, 20:43:00 GMT
permalink Post: 11921632
Incidentally, the APU door started opening *after* the initiation of relight of the first engine.
Without the APU, would there have been sufficient power to restart even one engine, never mind two?
Could this be why the delay between the first and second switches being moved to RUN?
Does it also mean that in reality the 10 seconds between OFF and RUN is immaterial as there was insufficient electrical power to start the engines anyway?
Without the APU, would there have been sufficient power to restart even one engine, never mind two?
Could this be why the delay between the first and second switches being moved to RUN?
Does it also mean that in reality the 10 seconds between OFF and RUN is immaterial as there was insufficient electrical power to start the engines anyway?
Normal start uses a lot of electrical power to drive the two starters. In a situation with only the RAT supplying electrical power there won't be anywhere near enough power to turn even one starter. Restart relies on windmilling only. Igniters don't need a huge amount of power, fuel will be gravity fed to the engine driven pumps. The APU autostart function will use power from the dedicated APU battery only.
Edit to add, it can take an age for the APU to start off the battery. Well over a minute.
July 13, 2025, 20:47:00 GMT
permalink Post: 11921636
I think there is a bit of confusion running in this thread about how the auto restart function works.
Normal start uses a lot of electrical power to drive the two starters. In a situation with only the RAT supplying electrical power there won't be anywhere near enough power to turn even one starter. Restart relies on windmilling only. Igniters don't need a huge amount of power, fuel will be gravity fed to the engine driven pumps. The APU autostart function will use power from the dedicated APU battery only.
Normal start uses a lot of electrical power to drive the two starters. In a situation with only the RAT supplying electrical power there won't be anywhere near enough power to turn even one starter. Restart relies on windmilling only. Igniters don't need a huge amount of power, fuel will be gravity fed to the engine driven pumps. The APU autostart function will use power from the dedicated APU battery only.
July 13, 2025, 20:48:00 GMT
permalink Post: 11921640
Thanks for confirming - the point I'm trying to make (apparently badly) is twofold:
1. There's a discussion here about the delay of 4 seconds between switching engine 1 and engine 2 to RUN. The fact is that this is irrelevant in terms of outcome given the lack of APU at the start of this process. Moreover if the lack of APU was known to the pilots, then it would potentially explain this delay anyway (what was the point in flicking the other switch yet)?
2. The lack of APU until at least 12-13 seconds after loss of engines, lack of electrical power from the engines, and at best limited electrical power from the RAT (and for a time, none), would have affected other systems used by the pilots during this short flight, at least for part of it. This hasn't been discussed basically at all, despite a lot of discussion around the ten second delay to start the engines restart, even though that power loss would have been in that window.
1. There's a discussion here about the delay of 4 seconds between switching engine 1 and engine 2 to RUN. The fact is that this is irrelevant in terms of outcome given the lack of APU at the start of this process. Moreover if the lack of APU was known to the pilots, then it would potentially explain this delay anyway (what was the point in flicking the other switch yet)?
2. The lack of APU until at least 12-13 seconds after loss of engines, lack of electrical power from the engines, and at best limited electrical power from the RAT (and for a time, none), would have affected other systems used by the pilots during this short flight, at least for part of it. This hasn't been discussed basically at all, despite a lot of discussion around the ten second delay to start the engines restart, even though that power loss would have been in that window.
Ok so:
1) There may be a technical reason outside of my scope for what you describe. From an operational point of view, for every EFATO I\x92ve ever done in the sim we are taught ANC. Initially our primary focus is flying the aircraft, hence why it\x92s being suggested this was the work of the PM, the only one with sufficient capacity capable of such at that moment. The fact the APU hasn\x92t come online whilst under such workload whilst falling out of the sky at 300ft wouldn\x92t be much of a consideration from the PF
2) Without power, altitude or airspeed nothing else really matters at that stage, does it? The APU takes longer to come online than this flight lasted!
July 13, 2025, 21:06:00 GMT
permalink Post: 11921654
Thank you for your reply! I'm aware you know more about ADS-B than I do, and I'm happy to learn.
As you know, I'm referring to the map view and data on https://www.flightradar24.com/blog/f...rom-ahmedabad/ .
That's what I thought at first, based on the time stamps.
08:08:50.87 last full ADS-B message (172 kts)
08:08:54 APU inlet door starts to open, per the report.
My problem here is that the report also says that the maximum speed was 180 knots IAS at about 08:08:42. And we have
2025-06-12T08:08:46.550875Z,8005ec,23.069138,72.625871,575
associated with 184 kts as the first ADS-B message in the sequence.
Given that the clocks of ADS-B receivers are sometimes off, I think this might actually represent the moment of maximum speed; but then the AFS-B clock would be 4 seconds fast.
And that's why I adjusted my times.
A way to cross-check would be to track the aircraft position over time from the point of rotation, or to use the new photo in the report that shows the RAT over the runway to triangulate where that was.
Yes.
Would low pressure and high temperature make IAS lower than ground speed, even with the 7 knot headwind?
Either way, if they were decelerating at approximately 3 knots per second, then they would've ended up at about 150 knots IAS, which is less than Vr.
When I look at the CCTV video, 13 seconds into the flight, the aircraft is just "over the hump" and starts descending, so that tracks.
At this point, I don't know what having the engines spool up instead of being dead weight would've done to that flight path; and how successfully the aircraft could've been recovered from that.
Maybe they had only 4 seconds to flip those switches, instead of 5 seconds?
Still, the best bet is to not ask questions, but flip these switches back ASAP, no?
As you know, I'm referring to the map view and data on https://www.flightradar24.com/blog/f...rom-ahmedabad/ .
08:08:50.87 last full ADS-B message (172 kts)
08:08:54 APU inlet door starts to open, per the report.
My problem here is that the report also says that the maximum speed was 180 knots IAS at about 08:08:42. And we have
2025-06-12T08:08:46.550875Z,8005ec,23.069138,72.625871,575
associated with 184 kts as the first ADS-B message in the sequence.
Given that the clocks of ADS-B receivers are sometimes off, I think this might actually represent the moment of maximum speed; but then the AFS-B clock would be 4 seconds fast.
And that's why I adjusted my times.
A way to cross-check would be to track the aircraft position over time from the point of rotation, or to use the new photo in the report that shows the RAT over the runway to triangulate where that was.
Beware of comparing the speeds from ADS-B, which are groundspeeds, with those from the report, which are IAS.
Would low pressure and high temperature make IAS lower than ground speed, even with the 7 knot headwind?
Either way, if they were decelerating at approximately 3 knots per second, then they would've ended up at about 150 knots IAS, which is less than Vr.
When I look at the CCTV video, 13 seconds into the flight, the aircraft is just "over the hump" and starts descending, so that tracks.
At this point, I don't know what having the engines spool up instead of being dead weight would've done to that flight path; and how successfully the aircraft could've been recovered from that.
Maybe they had only 4 seconds to flip those switches, instead of 5 seconds?
Still, the best bet is to not ask questions, but flip these switches back ASAP, no?
Last edited by Musician; 13th July 2025 at 21:36 .
July 13, 2025, 21:15:00 GMT
permalink Post: 11921667
Thank you for your reply! I'm aware you know more about ADS-B than I do, and I'm happy to learn.
As you know, I'm referring to the map view and data on https://www.flightradar24.com/blog/f...rom-ahmedabad/ .
That's what I thought at first, based on the time stamps.
08:08:50.87 last full ADS-B message (172 kts)
08:08:54 APU inlet door starts to open, per the report.
My problem here is that the report also says that the maximum speed was 180 knots IAS at about 808:08:42. And we have
2025-06-12T08:08:46.550875Z,8005ec,23.069138,72.625871,575
associated with 184 kts as the first ADS-B message in the sequence.
Given that the clocks of ADS-B receivers are sometimes off, I think this might actually represent the moment of maximum speed; but then the AFS-B clock would be 4 seconds fast.
And that's why I adjusted my times.
A way to cross-check would be to track the aircraft position over time from the point of rotation, or to use the new photo in the report that shows the RAT over the runway to triangulate where that was.
Yes.
Would low pressure and high temperature make IAS lower than ground speed, even with the 7 knot headwind?
Either way, if they were decelerating at approximately 3 knots per second, then they would've ended up at about 150 knots IAS, which is less than Vr.
When I look at the CCTV video, 13 seconds into the flight, the aircraft is just "over the hump" and starts descending, so that tracks.
At this point, I don't know what having the engines spool up instead of being dead weight would've done to that flight path; and how successfully the aircraft could've been recovered from that.
Maybe they had only 4 seconds to flip those switches, instead of 5 seconds?
Still, the best bet is to not ask questions, but flip these switches back ASAP, no?
As you know, I'm referring to the map view and data on https://www.flightradar24.com/blog/f...rom-ahmedabad/ .
That's what I thought at first, based on the time stamps.
08:08:50.87 last full ADS-B message (172 kts)
08:08:54 APU inlet door starts to open, per the report.
My problem here is that the report also says that the maximum speed was 180 knots IAS at about 808:08:42. And we have
2025-06-12T08:08:46.550875Z,8005ec,23.069138,72.625871,575
associated with 184 kts as the first ADS-B message in the sequence.
Given that the clocks of ADS-B receivers are sometimes off, I think this might actually represent the moment of maximum speed; but then the AFS-B clock would be 4 seconds fast.
And that's why I adjusted my times.
A way to cross-check would be to track the aircraft position over time from the point of rotation, or to use the new photo in the report that shows the RAT over the runway to triangulate where that was.
Yes.
Would low pressure and high temperature make IAS lower than ground speed, even with the 7 knot headwind?
Either way, if they were decelerating at approximately 3 knots per second, then they would've ended up at about 150 knots IAS, which is less than Vr.
When I look at the CCTV video, 13 seconds into the flight, the aircraft is just "over the hump" and starts descending, so that tracks.
At this point, I don't know what having the engines spool up instead of being dead weight would've done to that flight path; and how successfully the aircraft could've been recovered from that.
Maybe they had only 4 seconds to flip those switches, instead of 5 seconds?
Still, the best bet is to not ask questions, but flip these switches back ASAP, no?