Posts by user "Roo" [Posts: 20 Total up-votes: 23 Pages: 1]

Roo
2025-06-14T00:27:00
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Post: 11901024
Originally Posted by Old Boeing Driver
Everyone here should read post #867
It is a good post up until the point he adds the " two hypotheses that remain" . I await further evidence.

Subjects: None

2 users liked this post.

Roo
2025-06-14T02:03:00
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Post: 11901073
Originally Posted by Sailvi767
There is no auto flap retract on the 787.


Flap/Slat Load Relief
In the primary mode, the flap load relief system protects the flaps from excessive air loads. If flap airspeed placard limits are exceeded with the flaps in the 15 through 30 position, LOAD RELIEF is displayed and the flaps automatically retract to a safe position appropriate to the airspeed. Load relief retraction is limited to flaps 5. When airspeed is reduced, the flaps automatically re–extend as airspeed allows. Re–extension is limited to the commanded flap position.

Subjects: Flap Setting  Flaps (All)

2 users liked this post.

Roo
2025-06-14T02:10:00
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Post: 11901077
Originally Posted by krismiler
Does the B787 have auto flap retract ?
Yes, but it is only designed to retract them in to the Flap 5 position which is the first stage of TE flaps. BTW you will note from the image that F5 is a barely perceptible, hence this likely flap red herring.



Subjects: None

Roo
2025-06-14T02:25:00
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Post: 11901087
Originally Posted by Sailvi767
Thats a load relief system for a flap over speed. It never retracts the slats and only moves the flaps to the next position. There was definitely no overspeed of the flaps in this accident.
The aircraft has a system that can automatically retract the flaps to F5 in set circumstances. OP was supposing this system may have malfunctioned. That's all I will say.

Subjects: None

Roo
2025-06-15T13:14:00
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Post: 11902457
Originally Posted by fox niner
777/787 driver here.

Then the gear.
When you lift off the runway, the gear doors open REGARDLESS of gear lever position. If you do not raise the gear within 30 seconds, the gear doors close again and you keep the gear down as you apparently desire. In the video, the gear doors are closed again as the airplane flies into the suburb. This requires normal hydraulics in system C, which was apprently available as the doors are closed again..
Incorrect. Aircraft is a 787-8. It is does not have the early MLG door opening feature fitted to 787-9 & -10.

Subjects: Gear Retraction  MLG (All)

10 users liked this post.

Roo
2025-06-15T16:36:00
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Post: 11902616
Originally Posted by D Bru
I'm posting some YT-links to show that 787-8 and -9 gear doors seem to behave similar only when electing to actually retract the LG….
Well I am sorry but they don’t.
This yt video is somewhat cheesy, but it should make the -9 “early open” MLG door process clear to you, in a normal gear retraction. Unless you think this clown selected gear up on the ground.
They cycle open before gear is selected up (& even if gear is left down as you observed). Whereas on the -8 MLG doors will not budge until gear is selected up.



Last edited by Roo; 15th Jun 2025 at 16:47 .

Subjects: Gear Retraction  MLG (All)

1 user liked this post.

Roo
2025-06-14T02:03:00
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Post: 11903883
Originally Posted by Sailvi767
There is no auto flap retract on the 787.


Flap/Slat Load Relief
In the primary mode, the flap load relief system protects the flaps from excessive air loads. If flap airspeed placard limits are exceeded with the flaps in the 15 through 30 position, LOAD RELIEF is displayed and the flaps automatically retract to a safe position appropriate to the airspeed. Load relief retraction is limited to flaps 5. When airspeed is reduced, the flaps automatically re–extend as airspeed allows. Re–extension is limited to the commanded flap position.

Subjects: Flap Setting  Flaps (All)

Roo
2025-06-14T02:10:00
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Post: 11903884
Originally Posted by krismiler
Does the B787 have auto flap retract ?
Yes, but it is only designed to retract them in to the Flap 5 position which is the first stage of TE flaps. BTW you will note from the image that F5 is a barely perceptible, hence this likely flap red herring.

Subjects: None

Roo
2025-06-14T02:25:00
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Post: 11903885
Originally Posted by Sailvi767
Thats a load relief system for a flap over speed. It never retracts the slats and only moves the flaps to the next position. There was definitely no overspeed of the flaps in this accident.
The aircraft has a system that can automatically retract the flaps to F5 in set circumstances. OP was supposing this system may have malfunctioned. That's all I will say.

Subjects: None

Roo
2025-06-15T13:14:00
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Post: 11903886
Originally Posted by fox niner
777/787 driver here.

Then the gear.
When you lift off the runway, the gear doors open REGARDLESS of gear lever position. If you do not raise the gear within 30 seconds, the gear doors close again and you keep the gear down as you apparently desire. In the video, the gear doors are closed again as the airplane flies into the suburb. This requires normal hydraulics in system C, which was apprently available as the doors are closed again..
Incorrect. Aircraft is a 787-8. It is does not have the early MLG door opening feature fitted to 787-9 & -10.

Subjects: Gear Retraction  MLG (All)

Roo
2025-06-15T16:36:00
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Post: 11903887
Originally Posted by D Bru
I'm posting some YT-links to show that 787-8 and -9 gear doors seem to behave similar only when electing to actually retract the LG….
Well I am sorry but they don’t.
This yt video is somewhat cheesy, but it should make the -9 “early open” MLG door process clear to you, in a normal gear retraction. Unless you think this clown selected gear up on the ground.
They cycle open before gear is selected up (& even if gear is left down as you observed). Whereas on the -8 MLG doors will not budge until gear is selected up.


Subjects: Gear Retraction  MLG (All)

Roo
2025-06-17T00:12:00
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Post: 11903880
Originally Posted by CV880
Aerospace101 post makes a good point about the gear tilt. When jacking an aircraft with hydraulics off the trucks will often self-rotate with the heavier end obviously going down. Since the 787 truck position actuator is on the forward end of the truck it is probable that is the heavier end therefore the truck is likely to rotate nose down without hydraulics.
Not to mention aerodynamic forces as well.

Subjects: MLG Tilt

Roo
2025-06-18T09:17:00
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Post: 11905048
Originally Posted by FullWings
I think the minimum autopilot engagement height is a FCOM limitation but not necessarily a limitation of the system, i.e. you can engage the AP lower than that but it hasn\x92t been technically qualified to work in all circumstances, although it might actually do that..
No it is actually a system limitation on the 787. A/P won't engage after TO below 200' rad alt. There is some form of interconnect/lockout in place. If you try engage at 195' you just get the AP disconnect tone.

Subjects: FCOM

3 users liked this post.

Roo
2025-06-18T09:44:00
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Post: 11905074
Originally Posted by FullWings
That’s interesting and different from the 777 logic. Have you actually tried this in the sim or otherwise?
Yep numerous times in the sim over the years. Typically when overly exuberantly trying to get AP in after a V1 cut. RA is right in your face on the HUD & if you don't wait til 200' RA, AP will not not engage.

Subjects: V1

3 users liked this post.

Roo
2025-06-19T11:19:00
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Post: 11905941
The RAT is a small turbine that operates an electrical generator and a hydraulic pump.
Well said thanks &
“A ram air turbine (RAT) pump converts mechanical input power into hydraulic power for the center system flight controls. The RAT is in the right, aft wing-to-body fairing.”

Last edited by Saab Dastard; 19th Jun 2025 at 12:11 . Reason: Quoting deleted post

Subjects: Generators/Alternators  Hydraulic Failure (All)  Hydraulic Pumps  RAT (All)

Roo
2025-06-19T21:14:00
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Post: 11906379
Originally Posted by aerobat77
you follow the shutdown procedures , one of the first items is to retard the power lever to idle . With levers in idle they will shutdown , above idle they will not .

Subjects: None

1 user liked this post.

Roo
2025-06-20T12:42:00
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Post: 11906937
Originally Posted by Feathers McGraw
VT-ANB flew DEL-AMD, approximately 1hr 15 minutes, before its fatal departure from AMD.

Does anyone know if fuel was added at AMD or was the total fuel required to LGW already aboard on departure from DEL?
Unlikely to have tankered in fuel & even if they did they would still have had to uplift more. It would be normal to load the onward fuel in AMD having only flown in with what they needed for the short sector.. Would most likely have departed DEL with wing tank fuel only and an empty centre tank. I wont speculate here but I do wonder what works might have occurred in the 8 hour stop in DEL.

Subjects: Centre Tank

Roo
2025-06-20T15:02:00
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Post: 11907040
Originally Posted by Gary Brown
If I may - going back to the upthread report of an Indian Express newspaper interview with "an official" who was pointing at possible "water contamination". This is very misleading by either the "official" or the newspaper. The incident specified by "the official" near Gatwick in 2020 is this one:
https://www.gov.uk/aaib-reports/airc...-february-2020
which was explicitly biocide contamination not water. As in the Japanese similar case discussed here already, the excessive biocide use caused chemical reactions in the fuel that - eventually - caused starvation and abrupt shutdown.
<snip>
So, some questions. If the investigators are looking at a biocide contamination:
- after such a fireball, would there be any way of determining whether the fuel had in fact been biocide contaminated? Perhaps the inner surfaces of the tanks? Assorted valves and piping along the fuel route?
- what relevant engine parameters are captured and (hopefully) usefully recorded by the FDRs? A couple of incident reports have mentioned monitoring of the exhaust gases, with an ability to detect contaminants as they are expelled.
- does anyone here know what records are kept regarding the biocide treatment at the point of fuelling? Iirc, in the Japanese incident it was forensic interviews with the ground crew responsible that revealed the details of the error, rather than captured hard data.
Gary Brown Yes that was what I was wondering too. Biocide contamination not water. Hence my earlier curiosity about what might have occurred to the aircraft in the DEL stopover. If the inner surface of just the centre tank somehow got contaminated there, any issues may have been hidden flying with the tank empty and the problem only arose on the subsequent sector when the tank was used.

Subjects: Biocide  Centre Tank  Parameters

Roo
2025-06-27T06:59:00
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Post: 11911701
Originally Posted by Musician
A few days ago, I created a "wiki post" at the top of this thread, where I hoped we could collect "must-read" information. If you don't have the requisite 90 days/90 posts to edit it, feel free to PM me with what you'd like to have added.
https://www.pprune.org/recentforumwikiposts.php
Thanks for doing this.
Someone else created an external page a few days ago that indexed and sorted all the topical posts in this thread and the original one under major headings.
I can no longer find it. Did that get deleted by mods for non compliance or is it still around somewhere?

Subjects: None

Roo
2025-07-01T13:22:00
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Post: 11914270
Originally Posted by MaybeItIs
....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..
You are correct in saying both engines draw from the centre tank on TO when there is sufficient fuel in them. But it is no revelation to anybody who flies the 787 and it has been bought up many times earlier in the thread. Going back at least two weeks. Here are just two examples, there are no doubt more.

Plane crash near Ahmedabad..
Plane crash near Ahmedabad..

Gets tiring correcting glaring errors such as the recent one wrongly asserting separate tanks for each engine is mandatory on TO or that it is routine to turn centre pumps on at 10,000'. Many of us just read it and say "that is clearly BS", "The person has not read the thread", then move on looking for some actual updated information, or news, while not speculating at all.




Subjects: Centre Tank

1 user liked this post.