Compton3fox
2025-06-16T05:48:00
permalink Post: 11903113

Quote:

Originally Posted by grumpyoldgeek

Firstly. I find all the speculation about hearing the RAT suspect. Not that I doubt observers heard something sounding like a RAT, but that I question the fidelity of the low bit rate and bit depth of the audio to reproduce the difference between the sound of a deployed or non-deployed RAT. The audio sounds quite distorted and I have zero confidence that anyone could accurately tell. Secondly, is the speculation about best glide performance. Any private pilot knows that best glide does not exist until the pilot pitches the nose down and establishes it. As far as I can see, there is no time nor visible indication that the nose pitched down. What I see is the aircraft mushing down to the ground with the nose high and just short of a stall.

You need to read the previous posts. We are NOT relying on ear witness's alone, 2 independent PPRUNE folks did detailed audio comparisons and the evidence is compelling. Plus people close to the Boeing test airfields in the US who have heard RAT tests 500+ times. The RAT was out, that's a 99% certainty. What else would make a sound like prop blades getting close to or perhaps exceeding the speed of sound?

Subjects: RAT (All)

6 users liked this post.

Compton3fox
2025-06-16T08:37:00
permalink Post: 11903256

Quote:

Originally Posted by grumpyoldgeek

Not trying to be a smart ass, but how do you "ground test" a RAT?

Extremely fast taxi!

Subjects: RAT (All)

4 users liked this post.

Compton3fox
2025-06-16T09:13:00
permalink Post: 11903296

Quote:

Originally Posted by jimtx

For the sake of argument, I hope you know what you are talking about. Because I don't.

Have a read of this.. https://termaviation.com/what-is-btc-in-aviation/

Subjects: None

Compton3fox
2025-06-16T09:21:00
permalink Post: 11903303

Quote:

Originally Posted by 172_driver

I have not read it all so pardon me if this has been covered already. The A350 had two separate cases of engines shutting down due to spilled coffee on the center console. It was just a thought that occurred to me, a forgotten water bottle left on the center console during rotation? Pilots are usually quite conscious about the liquid free areas but this happens at home, in the office... If someone with insight care to explain how the electrics is protected I am listening...

It was posted but in a nutshell:

Airbus assumed their pilots would not spill their drinks but they did, and this resulted in an un-commanded dual engine shutdown. Now they have to use Sippy Cups!

Boeing assumed their pilots would spill their drinks so made the system robust enough to tolerate liquid spills without shutting down the engines.

Subjects: Dual Engine Failure Engine Failure (All) Engine Shutdown

1 user liked this post.

Compton3fox
2025-06-16T09:41:00
permalink Post: 11903328

Quote:

Originally Posted by FlyingUpsideDown

The PF could've been task focused flying manually, following the FD's and not expecting the sinking feeling of losing the lift. The PM has made the mistake without knowing. ie. he/she has selected the flaps all the way to UP believing that the gear was now retracting. Both pilots now think the gear is retracting, they have full thrust but are sinking into the ground. "Professional crews" like Air France for eg. have made way worse decisions. Slats are extended because they are the last to retract. I'm not convinced the RAT is deployed. If it has deployed it could've been a last ditch effort for the crew to bring the fuel control switches from RUN to CUTOFF & back to RUN believing they've had a dual engine failure. This would account for the RAT if it did deploy. The APU inlet door could've been open as well because they were carrying out an APU to Pack takeoff. Once the aircraft is airborne and the weight-on-wheels (WOW) switches indicate air mode , the main gear bogies automatically tilt to the neutral position before retraction. Also when the flaps passed the last takeoff position on the quadrant, the Landing gear configuration warning horn would've sounded further confusing the pilots.

If you read the thread, you would know:

The RAT was almost certainly deployed. 4 different sources.
The Flaps were not retracted. Visible at the accident site plus many other sources agreeing they were indeed down.
APU will autostart when all engine power is lost. Potentially explaining why the inlet door was open or partially open at the accident site. Mentioned in several previous posts
On a 787-8, the main bogies tilt as the 1st action of the gear retract sequence. As stated in previous posts. I don't think this happens unless gear is selected up. So the conclusion was, gear was selected up. One caveat, IIRC, there was some discussion around a failure could have caused the bogies to tilt without Gear up being selected but I don't recall the outcome.
As for the Air France remark, un-necessary IMHO. Let's respect the crews please.

Subjects: APU Dual Engine Failure Engine Failure (All) Fuel (All) Fuel Cutoff Gear Retraction MLG Tilt RAT (All) RAT (Deployment)

5 users liked this post.

Compton3fox
2025-06-16T05:48:00
permalink Post: 11903743

Quote:

Originally Posted by grumpyoldgeek

Subjects: RAT (All)

1 user liked this post.

Compton3fox
2025-06-16T09:41:00
permalink Post: 11903755

Quote:

Originally Posted by FlyingUpsideDown

Subjects: APU Dual Engine Failure Engine Failure (All) Fuel (All) Fuel Cutoff Gear Retraction MLG Tilt RAT (All) RAT (Deployment)

Compton3fox 2025-06-16T05:48:00 permalink Post: 11903113	Quote: Originally Posted by grumpyoldgeek Firstly. I find all the speculation about hearing the RAT suspect. Not that I doubt observers heard something sounding like a RAT, but that I question the fidelity of the low bit rate and bit depth of the audio to reproduce the difference between the sound of a deployed or non-deployed RAT. The audio sounds quite distorted and I have zero confidence that anyone could accurately tell. Secondly, is the speculation about best glide performance. Any private pilot knows that best glide does not exist until the pilot pitches the nose down and establishes it. As far as I can see, there is no time nor visible indication that the nose pitched down. What I see is the aircraft mushing down to the ground with the nose high and just short of a stall. You need to read the previous posts. We are NOT relying on ear witness's alone, 2 independent PPRUNE folks did detailed audio comparisons and the evidence is compelling. Plus people close to the Boeing test airfields in the US who have heard RAT tests 500+ times. The RAT was out, that's a 99% certainty. What else would make a sound like prop blades getting close to or perhaps exceeding the speed of sound? Subjects: RAT (All) 6 users liked this post.
Compton3fox 2025-06-16T08:37:00 permalink Post: 11903256	Quote: Originally Posted by grumpyoldgeek Not trying to be a smart ass, but how do you "ground test" a RAT? Extremely fast taxi! Subjects: RAT (All) 4 users liked this post.
Compton3fox 2025-06-16T09:13:00 permalink Post: 11903296	Quote: Originally Posted by jimtx For the sake of argument, I hope you know what you are talking about. Because I don't. Have a read of this.. https://termaviation.com/what-is-btc-in-aviation/ Subjects: None
Compton3fox 2025-06-16T09:21:00 permalink Post: 11903303	Quote: Originally Posted by 172_driver I have not read it all so pardon me if this has been covered already. The A350 had two separate cases of engines shutting down due to spilled coffee on the center console. It was just a thought that occurred to me, a forgotten water bottle left on the center console during rotation? Pilots are usually quite conscious about the liquid free areas but this happens at home, in the office... If someone with insight care to explain how the electrics is protected I am listening... It was posted but in a nutshell: Airbus assumed their pilots would not spill their drinks but they did, and this resulted in an un-commanded dual engine shutdown. Now they have to use Sippy Cups! Boeing assumed their pilots would spill their drinks so made the system robust enough to tolerate liquid spills without shutting down the engines. Subjects: Dual Engine Failure Engine Failure (All) Engine Shutdown 1 user liked this post.
Compton3fox 2025-06-16T09:41:00 permalink Post: 11903328	Quote: Originally Posted by FlyingUpsideDown The PF could've been task focused flying manually, following the FD's and not expecting the sinking feeling of losing the lift. The PM has made the mistake without knowing. ie. he/she has selected the flaps all the way to UP believing that the gear was now retracting. Both pilots now think the gear is retracting, they have full thrust but are sinking into the ground. "Professional crews" like Air France for eg. have made way worse decisions. Slats are extended because they are the last to retract. I'm not convinced the RAT is deployed. If it has deployed it could've been a last ditch effort for the crew to bring the fuel control switches from RUN to CUTOFF & back to RUN believing they've had a dual engine failure. This would account for the RAT if it did deploy. The APU inlet door could've been open as well because they were carrying out an APU to Pack takeoff. Once the aircraft is airborne and the weight-on-wheels (WOW) switches indicate air mode , the main gear bogies automatically tilt to the neutral position before retraction. Also when the flaps passed the last takeoff position on the quadrant, the Landing gear configuration warning horn would've sounded further confusing the pilots. If you read the thread, you would know: The RAT was almost certainly deployed. 4 different sources. The Flaps were not retracted. Visible at the accident site plus many other sources agreeing they were indeed down. APU will autostart when all engine power is lost. Potentially explaining why the inlet door was open or partially open at the accident site. Mentioned in several previous posts On a 787-8, the main bogies tilt as the 1st action of the gear retract sequence. As stated in previous posts. I don't think this happens unless gear is selected up. So the conclusion was, gear was selected up. One caveat, IIRC, there was some discussion around a failure could have caused the bogies to tilt without Gear up being selected but I don't recall the outcome. As for the Air France remark, un-necessary IMHO. Let's respect the crews please. Subjects: APU Dual Engine Failure Engine Failure (All) Fuel (All) Fuel Cutoff Gear Retraction MLG Tilt RAT (All) RAT (Deployment) 5 users liked this post.
Compton3fox 2025-06-16T05:48:00 permalink Post: 11903743	Quote: Originally Posted by grumpyoldgeek Firstly. I find all the speculation about hearing the RAT suspect. Not that I doubt observers heard something sounding like a RAT, but that I question the fidelity of the low bit rate and bit depth of the audio to reproduce the difference between the sound of a deployed or non-deployed RAT. The audio sounds quite distorted and I have zero confidence that anyone could accurately tell. Secondly, is the speculation about best glide performance. Any private pilot knows that best glide does not exist until the pilot pitches the nose down and establishes it. As far as I can see, there is no time nor visible indication that the nose pitched down. What I see is the aircraft mushing down to the ground with the nose high and just short of a stall. You need to read the previous posts. We are NOT relying on ear witness's alone, 2 independent PPRUNE folks did detailed audio comparisons and the evidence is compelling. Plus people close to the Boeing test airfields in the US who have heard RAT tests 500+ times. The RAT was out, that's a 99% certainty. What else would make a sound like prop blades getting close to or perhaps exceeding the speed of sound? Subjects: RAT (All) 1 user liked this post.
Compton3fox 2025-06-16T09:41:00 permalink Post: 11903755	Quote: Originally Posted by FlyingUpsideDown The PF could've been task focused flying manually, following the FD's and not expecting the sinking feeling of losing the lift. The PM has made the mistake without knowing. ie. he/she has selected the flaps all the way to UP believing that the gear was now retracting. Both pilots now think the gear is retracting, they have full thrust but are sinking into the ground. "Professional crews" like Air France for eg. have made way worse decisions. Slats are extended because they are the last to retract. I'm not convinced the RAT is deployed. If it has deployed it could've been a last ditch effort for the crew to bring the fuel control switches from RUN to CUTOFF & back to RUN believing they've had a dual engine failure. This would account for the RAT if it did deploy. The APU inlet door could've been open as well because they were carrying out an APU to Pack takeoff. Once the aircraft is airborne and the weight-on-wheels (WOW) switches indicate air mode , the main gear bogies automatically tilt to the neutral position before retraction. Also when the flaps passed the last takeoff position on the quadrant, the Landing gear configuration warning horn would've sounded further confusing the pilots. If you read the thread, you would know: The RAT was almost certainly deployed. 4 different sources. The Flaps were not retracted. Visible at the accident site plus many other sources agreeing they were indeed down. APU will autostart when all engine power is lost. Potentially explaining why the inlet door was open or partially open at the accident site. Mentioned in several previous posts On a 787-8, the main bogies tilt as the 1st action of the gear retract sequence. As stated in previous posts. I don't think this happens unless gear is selected up. So the conclusion was, gear was selected up. One caveat, IIRC, there was some discussion around a failure could have caused the bogies to tilt without Gear up being selected but I don't recall the outcome. As for the Air France remark, un-necessary IMHO. Let's respect the crews please. Subjects: APU Dual Engine Failure Engine Failure (All) Fuel (All) Fuel Cutoff Gear Retraction MLG Tilt RAT (All) RAT (Deployment)

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