Mr Optimistic
2025-06-12T12:18:00
permalink Post: 11899152

Quote:

Originally Posted by Del Prado

650 feet was mentioned. Can anyone confirm if that was height or altitude? (And what airfield elevation is)

BBC reckons
The last signal was received seconds after take-off, according to Flightradar24, when the plane was at 625 feet (airport altitude is about 200 feet).

Subjects: BBC FlightRadar24

1 user liked this post.

Mr Optimistic
2025-06-12T16:44:00
permalink Post: 11899453

Can anyone comment on the adsb ground speed data on the take off roll compared to typical v1 speed ?

Subjects: None

Mr Optimistic
2025-06-14T21:39:00
permalink Post: 11901865

Quote:

Originally Posted by BugBear

TCMA

Which side of V1 does TCMA lurk? If a pilot closes the throttles to abort, does the system allow it? After all, "too low thrust" is outside the contour....

Ya know, when every conceivable possibility (or close) has been de wormed, it"s usually something impossible, or too fearful...(Or dishonest, fraudulent, criminal ....etc ,?

From tdracer
However, TCMA is only active on the ground (unfamiliar with the 787/GEnx TCMA air/ground logic - on the 747-8 we used 5 sources of air/ground - three Radio Altimeters and two Weight on Wheels - at least one of each had to indicate ground to enable TCMA). TCMA will shutdown the engine via the N2 overspeed protection - nearly instantaneous. For this to be TCMA, it would require at least two major failures - improper air ground indication or logic, and improper TCMA activation logic (completely separate software paths in the FADEC). Like I said, very, very unlikely.

Subjects: Engine Over-speed (All) Engine Shutdown (Over-speed) FADEC GEnx TCMA Logic N2 Over-speed TCMA (Activation) TCMA (Air-ground Logic) TCMA (All) TCMA (Improper Activation) TCMA (Shutdown) V1 Weight on Wheels

2 users liked this post.

Mr Optimistic
2025-06-15T00:11:00
permalink Post: 11901982

SLF here. Nothing to add but I am impressed by whoever made the mayday call in those extenuating circumstances. Aviate and navigate are no longer an option but it takes calm presence of mind, fortitude and professionalism to do that.

Subjects: Mayday

2 users liked this post.

Mr Optimistic
2025-06-18T01:27:00
permalink Post: 11904825

Slf
I have read that below 400 ft the crew sit on their hands.
I have read that if there is a loss of thrust the crew will firewall the thrust levers.
Everything, the rat,the flightpath,grandma hearing no sound, points to almost simultaneous loss of thrust shortly after rotation.
So,if the recorded data shows the crew firewall the t/l but the engines didn't respond, and the recorded data didn't give any causality,wouldn't you have to ground the fleet ?

Subjects: None

1 user liked this post.

Mr Optimistic 2025-06-12T12:18:00 permalink Post: 11899152	Quote: Originally Posted by Del Prado 650 feet was mentioned. Can anyone confirm if that was height or altitude? (And what airfield elevation is) BBC reckons The last signal was received seconds after take-off, according to Flightradar24, when the plane was at 625 feet (airport altitude is about 200 feet). Subjects: BBC FlightRadar24 1 user liked this post.
Mr Optimistic 2025-06-12T16:44:00 permalink Post: 11899453	Can anyone comment on the adsb ground speed data on the take off roll compared to typical v1 speed ? Subjects: None
Mr Optimistic 2025-06-14T21:39:00 permalink Post: 11901865	Quote: Originally Posted by BugBear TCMA Which side of V1 does TCMA lurk? If a pilot closes the throttles to abort, does the system allow it? After all, "too low thrust" is outside the contour.... Ya know, when every conceivable possibility (or close) has been de wormed, it"s usually something impossible, or too fearful...(Or dishonest, fraudulent, criminal ....etc ,? From tdracer However, TCMA is only active on the ground (unfamiliar with the 787/GEnx TCMA air/ground logic - on the 747-8 we used 5 sources of air/ground - three Radio Altimeters and two Weight on Wheels - at least one of each had to indicate ground to enable TCMA). TCMA will shutdown the engine via the N2 overspeed protection - nearly instantaneous. For this to be TCMA, it would require at least two major failures - improper air ground indication or logic, and improper TCMA activation logic (completely separate software paths in the FADEC). Like I said, very, very unlikely. Subjects: Engine Over-speed (All) Engine Shutdown (Over-speed) FADEC GEnx TCMA Logic N2 Over-speed TCMA (Activation) TCMA (Air-ground Logic) TCMA (All) TCMA (Improper Activation) TCMA (Shutdown) V1 Weight on Wheels 2 users liked this post.
Mr Optimistic 2025-06-15T00:11:00 permalink Post: 11901982	SLF here. Nothing to add but I am impressed by whoever made the mayday call in those extenuating circumstances. Aviate and navigate are no longer an option but it takes calm presence of mind, fortitude and professionalism to do that. Subjects: Mayday 2 users liked this post.
Mr Optimistic 2025-06-18T01:27:00 permalink Post: 11904825	Slf I have read that below 400 ft the crew sit on their hands. I have read that if there is a loss of thrust the crew will firewall the thrust levers. Everything, the rat,the flightpath,grandma hearing no sound, points to almost simultaneous loss of thrust shortly after rotation. So,if the recorded data shows the crew firewall the t/l but the engines didn't respond, and the recorded data didn't give any causality,wouldn't you have to ground the fleet ? Subjects: None 1 user liked this post.

Posts by user "Mr Optimistic" [Posts: 5 Total up-votes: 6 Pages: 1]