Posts by user "MaybeItIs" [Posts: 29 Total up-votes: 31 Pages: 2]

Agreed. But the FAA itself does speculate - on what basis, I have no idea. They use the word "may", see here, last sentence (and in other ADs in the sequence):

https://www.federalregister.gov/d/2022-26933/p-18

This paragraph (and one before) is/are also worth a read - they see no rush to fix, obviously. https://www.federalregister.gov/d/2025-08346/p-20

100% Agree: any suggestion that it's in any way related to 171 is pure speculation. Sounds like these ADs apply only to small numbers of 787s. Don't even know if 171 was one of them.

But installing lavatories directly above EE Bays? Who's the genius...? .

Anyway, I make a point of not going 'there' during the last half of any long flight. They are frequently "awash" and unpleasant places to be. The washbasins themselves are also prone to the ejecting of water onto the floors. Agreed, it's a ####ty problem.

Yes, that was fairly much my point. The "Dream" was supposed to be revolutionary, "all" electric..., but it doesn't take a genius to copy an old, out-dated layout.

I see nothing wrong, everything right with the Main EE Bay being under the cockpit. It's the obvious place. But underneath a leak-prone lav? Even the plumbing fittings are problematic, often leaky. Water above, Electricity below... What do we anticipate? Time is the real issue here. We have two showers in our house. A few years on, both started leaking... It's not rocket science.

How can we have innovation and improvement without I & I? The more I learn...

Ask the Apollo astronauts? The ISS Crew members? But don't mention 9/11! The fireballs just don't compare.

It has been said that there are three stages of truth: ridicule, violent opposition and acceptance as self-evident. Obviously, we're not there yet

Of course the aircrew needs a lav within their easy reach. I don't have a cross section or plan to work with (Google not obliging), but if you post, I'll take a look. Likely, I'd compartmentalize the lav with the EE Bay space immediately below, and install a "bilge tray and drain" below the lav space and above the EE Bay compartment. If it has to be used for EE Bay gear, I'd probably rack the 28V Batteries there, with the required fireproof casings and exhaust ports etc. (Also absurd, but true.) And I'd make sure the batteries themselves were fully protected by moulded plastic "hats", similar to what they use on the big 12V battery pairs on large trucks. I guess you could fit a couple of TRUs there as well, again, well-protected from dripping conductive liquids... And maybe, you could house [one of?] the EE Bay air conditioner unit[s] there? But none of the flight-critical board racks or other sensitive electronic equipment. Any moisture-related faults there would be just too random and difficult to pin down.

If that's so true, why the ADs about leakage from the lavs, listed earlier?

Thanks, that's nice of you to confirm. Despite never working on one, I must have some idea...

Didn't I just say that? "with the required fireproof casings and exhaust ports etc." Ok, didn't mention thermal runaway, but that's the purpose of the fireproof boxes and exhaust ports. But the whole risk/ danger of thermal runaway is another issue, isn't it? There are safer batteries that are not lead-acid whales. Are the any other planes out there that need fireproof boxes and vent pipes to contain and purge burning battery fumes etc to the outside? It's not just the fumes that are the issue, of course.

Good to hear, hope you know them inside out and catch every issue. Please keep an eye out for trickles down walls in the EE Bays though.

Is this correct? I'm sure I've seen contradictory views, such as (paraphrasing): For TO, All pumps are On; the centre (tank) pumps have higher delivery pressure so they win the "Supply the Fuel" contest, unless they fail or their tank goes empty; in either case, their delivery pressure goes to zero and the wing tank pump(s) then get their turn.

Oops, too slow, answered already by Sailvi767

Hi TT,

Can I ask a question that I guess a few observers will also want to know? Is L/D (Lift-over-Drag?) the same as Glide Slope? I.e. for an L/D of 13, does that equate to 13 forward for 1 down? If so, even at 17, it doesn't look like it would make it.

Here?
Air India Ahmedabad accident 12th June 2025 Part 2

Interesting, interesting!

\xa7 25.903(b) includes the words: "in at least one configuration,"

It doesn't, that I can see, state that that configuration must be used during takeoff, though common sense would say it should.

Sorry, you missed the point I was trying to make. \xa7 25.903(b) does say that the fuel system must be able to operate in an isolated, two-sided mode (for a twin engined jet), such that nothing on one side, such as bad fuel, will adversely affect the other engine. Of course, during Takeoff, both sides drawing fuel from a Centre Tank containing a lot of contaminants (e.g. Fuel Bug matter, water) is a scenario that could bring down the plane. We are all aware of that. But the point I was trying to make is that although \xa7 25.903(b) requires "at least one configuration" that separates both systems entirely (such as Left engine drawing from Left Main Tank, and Right from Right) which can be configured, the Rule doesn't appear to make that compulsory for Takeoff.

A lot of other posters here have stated that according to FCOM instructions, the normal, accepted 787 Takeoff configuration is "Both sides draw from centre" if the Centre tanks have enough fuel in them. I think (maybe wrongly) that this (prior few posts) is the first time this exact point has been raised. I hope I'm correct there. If not, my humble apologies.

The great thing about this forum and sadly, this tragic accident, is that it's drawing a few previously little-known worms out of the woodwork.