Posts by user "D Bru" [Posts: 8 Total up-votes: 18 Pages: 1]

I'm posting some YT-links to show that 787-9 gear doors indeed open on lift-off, while the -8 gear doors open only when gear up is actually selected. I also include links to a 787-8 and a -9 that keep their LG down after departure. The 8 doors are not opening. The 9 doors do open again regardless and indeed close again about 30 seconds after lift-off.

1. 787-8 LG retraction: boogies tilt forward, doors open, boogies tilt inward: 2. 787-9 LG retraction: doors open on lift-off, boogies tilt forward before inward: 3. 787-8 LG kept down: doors remain closed: 4. 787-9 LG kept down: doors open and close again about 30 secs after lift-off:

Without a doubt one is looking at a very, very rare event, most likely the result of an unlikely/unlucky combination of issues, the grim gravity realised by the F/C (mayday) immediately after T/O. As a very, very FF/retired EU bureaucrat/economist/lawyer with an as ever staunch penchant for data/facts, I'm therefore wondering whether VT-ANB engines had already their EEC MN4 microprocessors replaced as mandated within 11000 cycles or 12 years per AD 2021-21-05 https://www.govinfo.gov/content/pkg/...2021-25491.pdf . This AD was prompted by in-service occurrences of loss of GEnX engines thrust control resulting in uncommanded high thrust. Uncommanded high trust on (at least one of) the engines during the TO-roll, in particular past V1, resulting in a discrepancy with the actual (likely derated)thrust settings, could have triggered TMCA on or just before lift-off.

Yes, there's another snag in the million dollar Q for the explanation. If the MN4 microprocessor can run amok, so could perhaps the TCMA not exactly act as intended. But I take in both your pertinent comments and will (as per the mods advice) from now on sit on my hands and only read until the prelim report hopefully soon!

BR, D Bru

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

Really, Grumpy? If aft EAFR (not RIPS supported) would have had any data/voice after elec failure following T/O, I think the AAIB would have been more than happy to extract everything from that one since it was found earlier and most likely more intact than the front one. Regards

That's exactly why I would really recommend reading through the NTSB FDR report on the 2013 JA829J Boston incident helpfully posted by EDLB . There's potentially a wealth of data concerning a to me at least surprisingly number of 2000 of parameters written on a 787 EAFR, that is that at least if there's elec power. Even the 10 min RIPS is useless if there's no data sent from electrically shut off systems.

Yes, possible electric failure on the eafr is of course a totally different story concerning voice recording

According to official data ( https://aim-india.aai.aero/eaip-v2-0...AAH-en-GB.html & https://https://aim-india.aai.aero/eaip-v2-05-2023/eAIP/VAAH-ADC.pdf ):
05 THRE 180ft, TDZE 186ft
23 THRE 189ft, TDZE 189ft.
Google maps directions gives for walking from the nearest road next to the 05 THR (end of 23) to the accident site "mostly flat", i.e. going up 1m and going down 4m. That indeed can't add up to 50ft below RWY, more like 10/20ft, depending on the RWY elevation reference point. Moreover, the two floor building Air India 171 struck is about 20ft high.