Someone Somewhere
July 14, 2025, 09:58:00 GMT
permalink Post: 11922018

Quote:

Originally Posted by The Brigadier

Quote:

Originally Posted by SRMman

Actually, we don't know who made the Mayday call.

The mods have previously chosen to delete my post with links to confirmatory sources on this point, so I won't bother here.

Is that the "Captain's friend heard CVR tape" report that came out before the CVR had been read out, or a different source?

The former seems very discredited.

Last edited by Someone Somewhere; 14th July 2025 at 10:17 .

Subjects (links are to this post in the relevant subject page so that this post can be seen in context): CVR MAYDAY Thread Moderation

Someone Somewhere
July 15, 2025, 04:45:00 GMT
permalink Post: 11922651

Quote:

Originally Posted by dingy737

1. Where is the Data showing the TIME STAMP of when each engine parameters FIRST indicated an Engine spooling down. ( N1- N2, RPM. FUEL FLOW. EGT)
2. if the time STAMP of any engine spool down data occurred prior to the first movement of the fuel start lever. Then any subsequent movement of the start levers must be seen as an attempt to restart.
3. so that timeline must be established. More data is required.

This seems to quite clearly answer the question: (from the prelim report)

Quote:

The aircraft achieved the maximum recorded airspeed of 180 Knots IAS at about 08:08:42
UTC and immediately thereafter , the Engine 1 and Engine 2 fuel cutoff switches transitioned
from RUN to CUTOFF position one after another with a time gap of 01 sec. The Engine N1
and N2 began to decrease from their take-off values as the fuel supply to the engines was cut
off .

Quote:

Originally Posted by LTC8K6

Requiring the throttle lever to be at idle seems like a good idea.

That's the Embraer option.

The other option I can imagine is a mechanical stop with an override button, like the landing gear lever. Can't switch the fuel levers off unless you're slow and on the ground, the engine is failed or on fire, or you push override.

Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Fuel (All) Fuel Cutoff Fuel Cutoff Switches Gear Lever Parameters Preliminary Report RUN/CUTOFF Relight Timeline (Preliminary Report)

Someone Somewhere
July 15, 2025, 07:07:00 GMT
permalink Post: 11922700

Quote:

Originally Posted by Musician

The problem with the switches with hinged covers is that they have a single, "safe" position when they're covered. But the fuel switch is safe at CUTOFF when parked, and safe at RUN when the aircraft is operating, so that won't work.

There are ways to have gates that can be closed in either position (and are perhaps spring-closed), but either they are going to be left open, are a PITA to operate a switch single-handedly, or operating the guard will become part of the muscle memory for operating the switch.

Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Fuel (All) Fuel Cutoff Switches Muscle Memory RUN/CUTOFF Switch Guards

Someone Somewhere July 14, 2025, 09:58:00 GMT permalink Post: 11922018	Quote: Originally Posted by The Brigadier Quote: Originally Posted by SRMman Actually, we don't know who made the Mayday call. The mods have previously chosen to delete my post with links to confirmatory sources on this point, so I won't bother here. Is that the "Captain's friend heard CVR tape" report that came out before the CVR had been read out, or a different source? The former seems very discredited. Last edited by Someone Somewhere; 14th July 2025 at 10:17 . Subjects (links are to this post in the relevant subject page so that this post can be seen in context): CVR MAYDAY Thread Moderation
Someone Somewhere July 15, 2025, 04:45:00 GMT permalink Post: 11922651	Quote: Originally Posted by dingy737 1. Where is the Data showing the TIME STAMP of when each engine parameters FIRST indicated an Engine spooling down. ( N1- N2, RPM. FUEL FLOW. EGT) 2. if the time STAMP of any engine spool down data occurred prior to the first movement of the fuel start lever. Then any subsequent movement of the start levers must be seen as an attempt to restart. 3. so that timeline must be established. More data is required. This seems to quite clearly answer the question: (from the prelim report) Quote: The aircraft achieved the maximum recorded airspeed of 180 Knots IAS at about 08:08:42 UTC and immediately thereafter , the Engine 1 and Engine 2 fuel cutoff switches transitioned from RUN to CUTOFF position one after another with a time gap of 01 sec. The Engine N1 and N2 began to decrease from their take-off values as the fuel supply to the engines was cut off . Quote: Originally Posted by LTC8K6 Requiring the throttle lever to be at idle seems like a good idea. That's the Embraer option. The other option I can imagine is a mechanical stop with an override button, like the landing gear lever. Can't switch the fuel levers off unless you're slow and on the ground, the engine is failed or on fire, or you push override. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Fuel (All) Fuel Cutoff Fuel Cutoff Switches Gear Lever Parameters Preliminary Report RUN/CUTOFF Relight Timeline (Preliminary Report)
Someone Somewhere July 15, 2025, 07:07:00 GMT permalink Post: 11922700	Quote: Originally Posted by Musician The problem with the switches with hinged covers is that they have a single, "safe" position when they're covered. But the fuel switch is safe at CUTOFF when parked, and safe at RUN when the aircraft is operating, so that won't work. There are ways to have gates that can be closed in either position (and are perhaps spring-closed), but either they are going to be left open, are a PITA to operate a switch single-handedly, or operating the guard will become part of the muscle memory for operating the switch. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Fuel (All) Fuel Cutoff Switches Muscle Memory RUN/CUTOFF Switch Guards

Posts by user "Someone Somewhere" [Posts: 63 Total up-votes: 0 Pages: 4]