Page Links: Index Page
grumpyoldgeek
June 15, 2025, 02:05:00 GMT permalink Post: 11902051 |
Subjects (links are to this post in the relevant subject page so that this post can be seen in context): V1 |
grumpyoldgeek
June 15, 2025, 21:49:00 GMT permalink Post: 11902876 |
RAT and best glide
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.
Subjects (links are to this post in the relevant subject page so that this post can be seen in context): RAT (All) |
grumpyoldgeek
June 16, 2025, 00:51:00 GMT permalink Post: 11903014 |
Not trying to be a smart ass, but how do you "ground test" a RAT?
Subjects (links are to this post in the relevant subject page so that this post can be seen in context): RAT (All) RAT (Deployment) |
grumpyoldgeek
June 16, 2025, 00:51:00 GMT permalink Post: 11903733 |
Not trying to be a smart ass, but how do you "ground test" a RAT?
Subjects (links are to this post in the relevant subject page so that this post can be seen in context): RAT (All) RAT (Deployment) |
grumpyoldgeek
June 19, 2025, 18:47:00 GMT permalink Post: 11906262 |
Has it been determined from the wreckage that the RAT was deployed at the time of impact?
Subjects (links are to this post in the relevant subject page so that this post can be seen in context): RAT (All) RAT (Deployment) |
grumpyoldgeek
June 19, 2025, 23:59:00 GMT permalink Post: 11906498 |
Can someone help me with the calculations on how far from the point of our last ADS-B readout we can expect the stricken jet to fly/glide?
I am assuming the take off mass around 190-200 tons with 50 tons of fuel. For the glide phase this is of no importance, however. Data on the Internet puts the glide ratio of a 789 around 18-21:1. Gear and flaps/slats out should have a significant negative effect. Does anyone have a good take how much? Minus 40%? From the available data we can infer the plane never was higher than 200\x92 AAL, maybe even 100\x92. If I understood the online sources correctly, the point of impact was only about 20\x92 lower than the average runway level. If I am not mistaken the distance from the last ADS-B point to the impact site is about 2 km as per Reuters and the Guardian. That would put it at 6,500\x92. I just can\x92t get these numbers over each other without the aircraft producing thrust. Please help me correcting the numbers. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): ADSB |
grumpyoldgeek
June 26, 2025, 21:58:00 GMT permalink Post: 11911531 |
Thx, this indicates at least two issues:
1. The investigation's reliance on the front RIPS battery backuped EAFR indicates a confirmation of a total electrical power loss; 2. Earlier reports (i.e. AVH, now removed) of successful readout of and observations from CVR have proven outright fake. Regards, D Bru Subjects (links are to this post in the relevant subject page so that this post can be seen in context): CVR EAFR RIPS |
grumpyoldgeek
July 13, 2025, 01:51:00 GMT permalink Post: 11920984 |
Would not expect an FDR dedicated pole. They
might
pull the FCS position from the FADEC, since what really matters is what the FADEC receives as a command. I would expect two poles dedicated to the two circuits, one routed to each FADEC channel, and the others to the non-FADEC-reset-command functions.
Subjects (links are to this post in the relevant subject page so that this post can be seen in context): DFDR FADEC FDR |
grumpyoldgeek
July 14, 2025, 23:56:00 GMT permalink Post: 11922584 |
Subjects: None |
Page Links: Index Page