Airplane and airline stuff

[macdoc]

Air India crash Glad to see a bit of backtracking from this guy.
Good summary and just about the situation I called from dot one.

[Tero]

This is hard to cut and paste from. RAT came out.
https://www.ndtv.com/india-news/delhi-p ... ks-8690258

[macdoc]

[Tero]

India to send black box from crashed Air India to US for analysis
India will send the black box from the crashed Air India Boeing 787 Dreamliner to the US for analysis after it sustained extensive external damage, The Economic Times has reported, citing an internal source.

The National Transportation Safety Board (NTSB) in Washington will handle the extraction, with findings shared with India’s Aircraft Accident Investigation Bureau (AAIB).

“While AAIB had established a laboratory at its headquarters in Delhi last year, it is yet to be properly equipped to extract data from recorders which have sustained heavy damage. The NTSB team will carry them to their lab under protection and supervision from Indian officials to ensure that proper protocols are followed,” a person involved in the process told ET.

The Independent

[macdoc]

Seems settled on what happened in a very rare dual engine failure.
Waiting on why.

[pErvinalia]

Biden is why.

[macdoc]

you are incorrigible

This is plausible

[Tero]

It's confusing. I underatand a fuel pump shutoff valve. But it lacks a sequence of events. Power gliitch starts it all?

[macdoc]

He goes through the sequence - instead of a complete electrical power loss it's an erratic one that just gives enough time for the valves to close

[macdoc]

From a 787 pilot

PPRuNe Forums

Hello, this is my first post on pprune; as a 787 pilot I’m also puzzled by this accident. All seem to agree that for some reason there was a complete electrical failure and RAT deployment. With a complete electrical failure all six main fuel pumps fail. Each engine also has two mechanically driven fuel pumps. On takeoff, if there is fuel in the center tank, it will be used first, pumped by the two center tank pumps.
My airline’s manuals don’t go into much detail, but I read on another site that if both the center tank pumps fail, the engine driven pumps aren’t able to suction feed well enough from the center tanks to sustain engine operation. If there was fuel in the center tanks, a complete electrical failure would soon lead to center tank fuel pumps failure (all fuel pumps failure as stated previously) and fuel starvation of both engines. A rescue from this situation would be an immediate selection of both center tank fuel pumps OFF (not if my airline’s non-normal checklists) and waiting for successful suction feed from the L and R main tanks to occur, this would take a number of seconds.

https://boards.straightdope.com/t/the-g ... 00499/7999

[macdoc]

Seems a definitive thread to follow

https://www.pprune.org/accidents-close- ... -a-54.html

[Tero]

Shampooing planes for efficiency:

Do airliners have sensors to measure their takeoff weight, or is it just calculated by reference to known values?

Yes and no. When airliners go in for major periodic maintenance they are weighed. (I don't know if it's true or not but I heard about one company years ago that found that shampooing the carpets of a 747 resulted in a weight saving of a few hundred pounds, equivalent to a couple of passengers, mostly from sugar that had been deposited by spilled soft drinks.)

Subsequently that weight is used for takeoff weight calculations by adding fuel and payload.

Modern airliners can actually arrive at a pretty good estimate of their own weight, but only after they're airborne. The computers can determine gross weight by measuring various performance parameters.

https://www.reddit.com/r/aviation/comme ... ure_their/