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by OldAeroGuy
Sat Jun 13, 2020 2:01 pm
Forum: Civil Aviation
Topic: Boeing 777X Testing/Production Thread - 2020
Replies: 1293
Views: 246169

Re: Boeing 777X Testing/Production Thread - 2020

How many test flight hours are required for certification? I expect it is more successfully completing all of the various testing milestones than raw accumulation of hours, though some milestones will require certain minimum flight hours (the ETOPS testing, for example). Good answer. In addition, t...

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by OldAeroGuy
Thu Jun 04, 2020 12:00 pm
Forum: Civil Aviation
Topic: Boeing 777X Testing/Production Thread - 2020
Replies: 1293
Views: 246169

Re: Boeing 777X Testing/Production Thread - 2020

[quote="VCVSpotter"

According to this it was HPT ACC testing on June 2 (and no, I don’t know what that means but I’m sure someone on here does).
[/quote]

High Pressure Turbine -> HPT

Active Clearance Control -> ACC

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by OldAeroGuy
Sat May 30, 2020 7:43 pm
Forum: Civil Aviation
Topic: Boeing 777X Testing/Production Thread - 2020
Replies: 1293
Views: 246169

Re: Boeing 777X Testing/Production Thread - 2020

That flight is filed up to 35,000ft. Will this be the first flight up to cruising altitudes? No, on May 28, this airplane flew at FL340 and FL360. https://flightaware.com/live/flight/BOE2/history/20200528/2100Z/KBFI/KGEG Thanks OAG. Good to see the progress Today's flight is currently at FL400 afte...

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by OldAeroGuy
Sat May 30, 2020 5:32 pm
Forum: Civil Aviation
Topic: Boeing 777X Testing/Production Thread - 2020
Replies: 1293
Views: 246169

Re: Boeing 777X Testing/Production Thread - 2020

777-9 N779XX filed BFI-BFI as BOE2 11AM - 1:21PM https://flightaware.com/live/flight/BOE2 That flight is filed up to 35,000ft. Will this be the first flight up to cruising altitudes? No, on May 28, this airplane flew at FL340 and FL360. https://flightaware.com/live/flight/BOE2/history/20200528/2100...

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by OldAeroGuy
Sat May 23, 2020 1:55 pm
Forum: Civil Aviation
Topic: 777 - 25 years in commercial service
Replies: 147
Views: 14199

Re: 777 - 25 years in commercial service

Max Q wrote:
Was the triple the first Jet transport with a completely circular fuselage?


No, the A300 and it's derivatives (A310, A330 & A340) beat them to it.

There may be others, I'm feeling too lazy to research the topic right now.

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by OldAeroGuy
Fri May 22, 2020 1:35 pm
Forum: Civil Aviation
Topic: 777 - 25 years in commercial service
Replies: 147
Views: 14199

Re: 777 - 25 years in commercial service

https://runwaygirlnetwork.com/2018/11/0 ... 9-abreast/
-->

Dmoney wrote:
A330 and A350 are built so that 8&9 abreast is the only reasonable layout and perfectly fine.


But it's not like Airbus has never promoted 9 A/B on the A330.

https://runwaygirlnetwork.com/2018/11/0 ... 9-abreast/

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by OldAeroGuy
Tue May 12, 2020 10:49 pm
Forum: Civil Aviation
Topic: Boeing 777X Testing/Production Thread - 2020
Replies: 1293
Views: 246169

Re: Boeing 777X Testing/Production Thread - 2020

Which in turn put's a high load on the keel? - so if you had any concerns with Keel not having sufficient strength (it's what failed in the 777X wing test) then you would not run the tests? The tail loads during a stall are dynamic, ie the tail bounces around a lot in the wing wake and the concern ...

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by OldAeroGuy
Tue May 12, 2020 6:37 pm
Forum: Civil Aviation
Topic: Boeing 777X Testing/Production Thread - 2020
Replies: 1293
Views: 246169

Re: Boeing 777X Testing/Production Thread - 2020

Based on past Cert Program experience, I suspect the airplane has been stalled several times at all flap settings and at forward and aft CG's. The saw tooth altitude traces along with speed changes seen for some flight tests appear to indicate stall testing. Wing loads are not particularly high dur...

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by OldAeroGuy
Tue May 12, 2020 4:07 pm
Forum: Civil Aviation
Topic: Boeing 777X Testing/Production Thread - 2020
Replies: 1293
Views: 246169

Re: Boeing 777X Testing/Production Thread - 2020

Based on past Cert Program experience, I suspect the airplane has been stalled several times at all flap settings and at forward and aft CG's. The saw tooth altitude traces along with speed changes seen for some flight tests appear to indicate stall testing. Wing loads are not particularly high duri...

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by OldAeroGuy
Fri Mar 06, 2020 9:37 pm
Forum: Civil Aviation
Topic: Does Boeing continually improve their products?
Replies: 53
Views: 6679

Re: Do Boeing continually improve their products?

Yes. See how much better the 737 is today, compared to the one built in the late 50's. Incremental advances are visible. You're 10 years too early. The initial 737 EIS was in the late '60's. Well, the technology and the fuselage were from the 50’s. So it started off as a ”max” already. No, the tech...

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by OldAeroGuy
Fri Mar 06, 2020 3:54 am
Forum: Civil Aviation
Topic: Does Boeing continually improve their products?
Replies: 53
Views: 6679

Re: Do Boeing continually improve their products?

AirKevin wrote:
..... I remember right, the bacon lights were made more aerodynamic.


Yes, before the aerodynamic clean up, they made an annoying sizzling sound.

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by OldAeroGuy
Fri Mar 06, 2020 3:50 am
Forum: Civil Aviation
Topic: Does Boeing continually improve their products?
Replies: 53
Views: 6679

Re: Do Boeing continually improve their products?

Carlos01 wrote:
Yes. See how much better the 737 is today, compared to the one built in the late 50's. Incremental advances are visible.


You're 10 years too early.

The initial 737 EIS was in the late '60's.

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by OldAeroGuy
Fri Feb 14, 2020 1:09 am
Forum: Civil Aviation
Topic: Boeing 777X Testing/Production Thread - 2020
Replies: 1293
Views: 246169

Re: Boeing 777X Testing/Production Thread - 2020

Yesterday / Wednesday there were Boeing (Mounir) and FAA (Dickson) updates on 777X testing and certification. Boeing are anticipating 777X entry into service in 2 years. https://leehamnews.com/2020/02/13/max-777x-certifications-questions-abound-at-singapore-airshow/#more-32577 The Leeham article ha...

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by OldAeroGuy
Thu Feb 13, 2020 2:18 pm
Forum: Civil Aviation
Topic: Boeing 777X Testing/Production Thread - 2020
Replies: 1293
Views: 246169

Re: Boeing 777X Testing/Production Thread - 2020

Boeing 779 N779XW at GEG https://pbs.twimg.com/media/EQi_BC6XsAUY6_c?format=jpg https://pbs.twimg.com/media/EQi_BD_XsAw4VJH?format=jpg https://twitter.com/Peytonloumar/status/1227440976806936589?s=20 Your GEG pictures are interesting and they show a 777-9 feature I hadn't appreciated before. The in...

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by OldAeroGuy
Wed Feb 12, 2020 8:53 pm
Forum: Civil Aviation
Topic: Boeing 777X Testing/Production Thread - 2020
Replies: 1293
Views: 246169

Re: Boeing 777X Testing/Production Thread - 2020

Boeing 779 N779XW at GEG https://pbs.twimg.com/media/EQi_BC6XsAUY6_c?format=jpg https://pbs.twimg.com/media/EQi_BD_XsAw4VJH?format=jpg https://twitter.com/Peytonloumar/status/1227440976806936589?s=20 Your GEG pictures are interesting and they show a 777-9 feature I hadn't appreciated before. The in...

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by OldAeroGuy
Tue Feb 11, 2020 6:56 pm
Forum: Technical/Operations
Topic: Strange probes on the A350
Replies: 20
Views: 2782

Re: Strange probes on the A350

I've never seen a RAT test. Just how loud is it? Audible within the cabin/cockpit? From an observer perspective: Would the RAT be the loudest noice emanating on a landing? And while I'm sure this varies by Type, airspeed, etc: What kind of RPM are we talking? Is the RPM governed to an upper-limit? ...

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by OldAeroGuy
Sun Feb 09, 2020 8:49 pm
Forum: Civil Aviation
Topic: UTair 737-500 damaged in hard landing at Usinsk
Replies: 56
Views: 9129

Re: UTair 737-500 damaged in hard landing at Usinsk

According to AVHerald, the aircraft touchdown about 15 meters short of the paved runway. After going through "heaps of snow", the main gear collapsed. http://avherald.com/h?article=4d3110c1&opt=0 With no apparent fuel leakage, it looks like the landing gear fuse pins did their job. A ...

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by OldAeroGuy
Mon Feb 03, 2020 9:33 pm
Forum: Technical/Operations
Topic: One-engine operable climb gradients
Replies: 6
Views: 1135

Re: One-engine operable climb gradients

25.123 is the regulation for the net climb gradient associated with terrain clearance in the cruise configuration. The net climb gradient in the cruise configuration with one engine inoperative and the remaining engine(s) at maximum continuous thrust is the gross climb gradient reduced by: - 1.1% (T...

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by OldAeroGuy
Mon Feb 03, 2020 9:01 pm
Forum: Technical/Operations
Topic: One-engine operable climb gradients
Replies: 6
Views: 1135

Re: One-engine operable climb gradients

There is also the Approach Climb requirement of 25.121(d) Among other specifications: - one engine inoperative - gear up - flap setting stall speed no greater than 110% of the landing flap stall speed - minimum climb gradient of 2.1% (Twin), 2.4% (Tri) or 2.7% Quad Although this is named Approach Cl...

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by OldAeroGuy
Sat Feb 01, 2020 11:46 pm
Forum: Technical/Operations
Topic: Why no Trim Tank in the A350?
Replies: 40
Views: 3920

Re: Why no Trim Tank in the A350?

Given the 747 wing section and planform, the fuel burn advantage was only marginally better than the additional costs for the hardware, software and maintenance needed for CG control. Simplicity won out. The 747 did not use the h.stab fuel for cg control. It could only be filled on the ground and w...

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by OldAeroGuy
Fri Jan 31, 2020 10:01 pm
Forum: Technical/Operations
Topic: Why no Trim Tank in the A350?
Replies: 40
Views: 3920

Re: Why no Trim Tank in the A350?

The 747-400 airfoil is an older technology than the A330's supercritical airfoil and doesn't have the same aft loading. This reduces the advantage of using h. tail fuel to manage CG position. To what status in that domain did they push the revamped wing for the 748 ? Better than the 747-400, worse ...

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by OldAeroGuy
Fri Jan 31, 2020 9:53 pm
Forum: Technical/Operations
Topic: Why no Trim Tank in the A350?
Replies: 40
Views: 3920

Re: Why no Trim Tank in the A350?

I believe a 25% improvement in takeoff performance for h. tail fuel is very optimistic.

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by OldAeroGuy
Fri Jan 31, 2020 9:48 pm
Forum: Civil Aviation
Topic: Boeing 777X Testing/Production Thread - 2020
Replies: 1293
Views: 246169

Re: Boeing 777X Testing/Production Thread - 2020

Why aren't we getting any more videos of take off/landing??? Also, you got wonder what fuel burn numbers they're seeing. I mean you can model it all day long but real numbers are coming in. Sort of the proof in the pudding as to whether it's a viable frame vs. A35K. They need to expand the envelope...

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by OldAeroGuy
Thu Jan 30, 2020 1:58 pm
Forum: Technical/Operations
Topic: Why no Trim Tank in the A350?
Replies: 40
Views: 3920

Re: Why no Trim Tank in the A350?

Not having h.tail fuel and not using it for CG control if you do, simplifies fuel management. What are the potential savings when using it for CoG control? If the A330 trim tank CG control is inop, fuel burn increases by 1%, so that would seem a reasonable measure of the savings from the system. Th...

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by OldAeroGuy
Thu Jan 30, 2020 1:56 am
Forum: Technical/Operations
Topic: Why no Trim Tank in the A350?
Replies: 40
Views: 3920

Re: Why no Trim Tank in the A350?

Not having h.tail fuel and not using it for CG control if you do, simplifies fuel management. What are the potential savings when using it for CoG control? Given the 747 wing section and planform, the fuel burn advantage was only marginally better than the additional costs for the hardware, softwar...

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by OldAeroGuy
Wed Jan 29, 2020 6:28 pm
Forum: Technical/Operations
Topic: Why no Trim Tank in the A350?
Replies: 40
Views: 3920

Re: Why no Trim Tank in the A350?

Out of curiosity, does the 787 use a trim tank, or cruise flaps? Zeke is correct, the 787 and 777X use variable position cruise flaps to optimize airplane cruise performance. In general, Boeing has not used horizontal tail fuel tanks. The only Boeing transports to use h. tail fuel were the 747-400 ...

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by OldAeroGuy
Sun Jan 26, 2020 4:09 pm
Forum: Civil Aviation
Topic: Boeing 777-9 first flight 25 January 2020
Replies: 970
Views: 80190

Re: Boeing 777-9 first flight 25 January 2020

Jup! Horray for homonyms! MY question actually was if the 9X would be allowed to fly "thumbs up" :-)) No "thumbs up" flying. If the wing tips cannot be extended, the 777X is not flight worthy. What about ferry flight with both tips removed? I guess if things go tech, they can ma...

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by OldAeroGuy
Sun Jan 26, 2020 3:03 pm
Forum: Civil Aviation
Topic: Boeing 777-9 first flight 25 January 2020
Replies: 970
Views: 80190

Re: Boeing 777-9 first flight 25 January 2020

Congratulations to Boeing for this achievement! Great success! My only slight complaint is on aesthetics: I've seen pictures of her before, and with the folded wingtips she looks great. With the wingtips locked down she looks a bit... old style. Like an old 777, not like a modern, efficient and coo...

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by OldAeroGuy
Sun Jan 26, 2020 2:50 pm
Forum: Civil Aviation
Topic: Boeing 777-9 first flight 25 January 2020
Replies: 970
Views: 80190

Re: Boeing 777-9 first flight 25 January 2020

Was it ever made public if stuck up wingtips could be waived for flight? ( then both up, obviously ) I read your comment along the lines of: Was it ever made public if the aircraft waved its wingtips in flight? Would have been a nice gesture for the occasion :D Jup! Horray for homonyms! MY question...

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by OldAeroGuy
Tue Jan 21, 2020 5:43 pm
Forum: Civil Aviation
Topic: Boeing 777X Testing/Production Thread - 2020
Replies: 1293
Views: 246169

Re: Boeing 777X Testing/Production Thread - 2020

I expect there has been some consultation on certain points, but as I understand it, the FAA and EASA accepted each other's certifications generally prima facie . I expect that going forward, a joint certification process will become the standard, out of political necessity if nothing else (now tha...

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by OldAeroGuy
Fri Nov 29, 2019 8:44 pm
Forum: Civil Aviation
Topic: Pictures surfacing of 777X Sept Test Failure
Replies: 308
Views: 61600

Re: Pictures surfacing of 777X Sept Test Failure - they are Bad

The 777 currently has a maximum altitude of 43100 ft, which is a pressure of 2.34 psi in a standard atmosphere, if it maintains a 8000 ft (10.92 psi is the pressure at 8000 ft in a standard atmosphere) cabin at that altitude, the maximum pressure diff is 10.92-2.34=8.58 psi. The maximum diff if the...

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by OldAeroGuy
Fri Oct 11, 2019 3:11 pm
Forum: Civil Aviation
Topic: Boeing examines GEnX powered 767
Replies: 617
Views: 147126

Re: Boeing examines GEnX powered 767

Oh please, that's 1st generation work where super criticality (which is more than just sweep even by your own source) doesn't hold more than 20% the length of the wing. It meets the standard less than half the time. Your statements above show you have no understanding of 757 wing aerodynamics. That...

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by OldAeroGuy
Fri Oct 11, 2019 1:12 pm
Forum: Civil Aviation
Topic: Boeing examines GEnX powered 767
Replies: 617
Views: 147126

Re: Boeing examines GEnX powered 767

The 757 lacks a supercritical wing Where did you get this idea? As a demonstration of 757 wing technology, can you name another airliner with a 0.80M long range cruise speed that has 25 degree sweep wing? You're confused on definitions. Is the Truss-Braced Wing supercritical? No... The 737 MAX's wi...

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by OldAeroGuy
Thu Oct 10, 2019 11:50 pm
Forum: Civil Aviation
Topic: Boeing examines GEnX powered 767
Replies: 617
Views: 147126

Re: Boeing examines GEnX powered 767

patrickjp93 wrote:
The 757 lacks a supercritical wing


Where did you get this idea? As a demonstration of 757 wing technology, can you name another airliner with a 0.80M long range cruise speed that has 25 degree sweep wing?

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by OldAeroGuy
Wed Oct 09, 2019 12:08 am
Forum: Civil Aviation
Topic: Boeing 777X Testing Thread - 2019
Replies: 1441
Views: 369332

Re: Boeing 777X Testing Thread - 2019

Not quick at all. When I was a teenager I read Harry Potter & the Order of the Phoenix in just 14 hours. I've had over a week to read a document half as long by word count. Very admirable. I'm not sure of the relevance though unless it involves testing quidditch capable brooms. The real questio...

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by OldAeroGuy
Tue Oct 08, 2019 7:15 pm
Forum: Civil Aviation
Topic: Boeing 777X Testing Thread - 2019
Replies: 1441
Views: 369332

Re: Boeing 777X Testing Thread - 2019

I didn't advocate taking shortcuts or cutting corners. If it CAN be parallelized (for a reasonable price given the gains), then parallelize it! Manufacturing processes and algorithms are not so different. What leads you to believe this isn't already being done? Have you read AC25-7D yet? It's clear...

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by OldAeroGuy
Tue Oct 08, 2019 4:03 pm
Forum: Civil Aviation
Topic: Boeing 777X Testing Thread - 2019
Replies: 1441
Views: 369332

Re: Boeing 777X Testing Thread - 2019

patrickjp93 wrote:
I didn't advocate taking shortcuts or cutting corners. If it CAN be parallelized (for a reasonable price given the gains), then parallelize it! Manufacturing processes and algorithms are not so different.


What leads you to believe this isn't already being done?

Have you read AC25-7D yet?

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by OldAeroGuy
Thu Oct 03, 2019 3:49 am
Forum: Civil Aviation
Topic: Boeing 777X Testing Thread - 2019
Replies: 1441
Views: 369332

Re: Boeing 777X Testing Thread - 2019

patrickjp93 wrote:
Unless you yourself intend to get down in the mud with the people you disagree with, you have no right to disagree with them. That is the foremost essence of debate and integrity.


Have you read and understood AC25-7D? If you haven't, you're not down in the mud yet.

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by OldAeroGuy
Thu Oct 03, 2019 1:27 am
Forum: Civil Aviation
Topic: Boeing 777X Testing Thread - 2019
Replies: 1441
Views: 369332

Re: Boeing 777X Testing Thread - 2019

Then fire the cruft staff of the FAA and buy more test equipment and pilots or analysts. That's a terrible excuse. The FAA has been certifying craft for 60 years now. Much of this is highly understood and predictable. If you can have 6 craft in the air 7 days a week for a year and not have certific...

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by OldAeroGuy
Sun Sep 29, 2019 5:40 pm
Forum: Technical/Operations
Topic: Would a climb/glide schedule save fuel compared to a constant cruise altitude flight?
Replies: 34
Views: 5590

Re: Would a climb/glide schedule save fuel compared to a constant cruise altitude flight?

The most economical flight profile is a constantly climbing cruise to stay at optimum airframe M*(L/D). If the engine is well matched to the airframe, the engines will always be operating in the TSFC "bucket". The proposed saw tooth descent/climb proposal will always have the airframe oper...

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by OldAeroGuy
Sun Sep 08, 2019 4:50 pm
Forum: Civil Aviation
Topic: Boeing 777X Testing Thread - 2019
Replies: 1441
Views: 369332

Re: Boeing 777X Testing Thread - 2019

WIederling wrote:
OldAeroGuy wrote:
Which is the more difficult problem to solve, wing structure or a cargo door latch/structure?


"wings not coming off" has been mastered earlier than "doors not blowing out" afair.


While I'd prefer no failures, a cargo door failure is preferable to a wing failure.

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by OldAeroGuy
Sun Sep 08, 2019 4:43 pm
Forum: Civil Aviation
Topic: Boeing 777X Testing Thread - 2019
Replies: 1441
Views: 369332

Re: Boeing 777X Testing Thread - 2019

It better be an improperly closed latch, otherwise things are going beyond grim Ahh.. How soon we forget. https://www.flightglobal.com/news/articles/airbus-a380-test-wing-breaks-just-below-ultimate-load-204716/ Which is the more difficult problem to solve, wing structure or a cargo door latch/struc...

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by OldAeroGuy
Sun Sep 08, 2019 3:28 pm
Forum: Civil Aviation
Topic: Boeing 777X Testing Thread - 2019
Replies: 1441
Views: 369332

Re: Boeing 777X Testing Thread - 2019

It better be an improperly closed latch, otherwise things are going beyond grim Ahh.. How soon we forget. https://www.flightglobal.com/news/articles/airbus-a380-test-wing-breaks-just-below-ultimate-load-204716/ Which is the more difficult problem to solve, wing structure or a cargo door latch/struc...

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by OldAeroGuy
Sun Sep 01, 2019 3:23 pm
Forum: Civil Aviation
Topic: Smoky A350!
Replies: 45
Views: 13208

Re: Smoky A350!

zeke wrote:
Must be a problem with the air data system on that particular aircraft, the ACTDS (automatic chem trail delivery system) is not supposed to activate until they are in cruise.


With a hard BREXIT emerging, maybe the English are taking more direct action against the Irish. :D

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by OldAeroGuy
Sat Aug 31, 2019 3:10 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q3 2019
Replies: 4380
Views: 661433

Re: Boeing 737MAX Grounded Worldwide Q3 2019

So quite rightly, The NTSB is to review the whole new aircraft certification process to ensure it is fit for purpose. Something I mentioned weeks ago, but was not well received on A-Net. You were suggesting the NTSB take over all aircraft certification going forward, which is very different than re...

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by OldAeroGuy
Tue Aug 27, 2019 2:05 pm
Forum: Technical/Operations
Topic: How will ultrafan seal the variable pitch fan?
Replies: 18
Views: 6487

Re: How will ultrafan seal the variable pitch fan?

The 5000 lb is at Top of Climb. For a modern Twin, L/D = 20, so ToC Weight = 200,000 lb. At SL, Thrust = 23,000 to 27,000 lb So it appears the engine would be in the size ballpark for a NB Twin. Look at the fan diameters in the paper. :-) OK, let's compare the Direct Drive Turbofan with the CFM56-5...

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by OldAeroGuy
Mon Aug 26, 2019 11:02 am
Forum: Technical/Operations
Topic: How will ultrafan seal the variable pitch fan?
Replies: 18
Views: 6487

Re: How will ultrafan seal the variable pitch fan?

The 5000 lb is at Top of Climb.

For a modern Twin, L/D = 20, so ToC Weight = 200,000 lb.

At SL, Thrust = 23,000 to 27,000 lb

So it appears the engine would be in the size ballpark for a NB Twin.

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by OldAeroGuy
Mon Aug 19, 2019 2:34 pm
Forum: Technical/Operations
Topic: Boeing 787-10 Vref
Replies: 4
Views: 1355

Re: Boeing 787-10 Vref

https://www.boeing.com/resources/boeing ... ps/787.pdf


I don't believe there are any speed data for either takeoff or landing in your reference.
-->

Armadillo1 wrote:


I don't believe there are any speed data for either takeoff or landing in your reference.

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by OldAeroGuy
Mon Aug 19, 2019 2:32 pm
Forum: Technical/Operations
Topic: Boeing 787-10 Vref
Replies: 4
Views: 1355

Re: Boeing 787-10 Vref

captdoug56 wrote:
hello
2 questions . First what is the 787-10 Vref ?
Second where can I find takeoff speed cards for the 3 variants ?
thanks Doug


There is no single Vref for the 787 as it is a function of weight.

The same comment applies to takeoff speeds.

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by OldAeroGuy
Wed Aug 07, 2019 9:30 pm
Forum: Technical/Operations
Topic: Did/Does the 779X need a new wing? and does it need to be so big?
Replies: 47
Views: 8788

Re: Did/Does the 779X need a new wing? and does it need to be so big?

Wing loading plays a different role in performance than wing span, it comes down to the objective of the design and how it is optimized. Since lift = weight at cruise, and since wing loading = weight/ wing area, using the lift equation we get the following: Air density = (2 * gravity * wing loading...

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