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VV
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Re: Boeing 777X Testing/Production Thread - 2020

Tue Mar 03, 2020 8:30 pm

dagKentWA wrote:
...
I've been tracking the flights on flightaware.com, and I've seen a lot of exactly what you describe - up & down, faster & slower. They've also landed & taken off at Spokane (GEG) several times, which would make sense if they are looking for optimum landing speeds & configuration.


It is possible there are a lot of similarities with the 777-300ER in term of the "guts" or the systems and thus the most important items to confirm is the handling characteristics and "low-speed" (field) performance. Hence the focus on that part during the early part of the flight test.

If they manage to completely firm the configuration and also to freeze all the small details of the flight control system (gains, etc.) then they can immediately implement the configuration to each and every fight test articles. This comment also applies to the production aircraft.

I suspect they start "at risk" the manufacturing of production aircraft that are to be delivered to airlines. When I say "at risk" it means that they build production units as early as possible in order to maintain 777 production continuity even when the 777-9's flight test is still in progress.
 
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bikerthai
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Re: Boeing 777X Testing/Production Thread - 2020

Tue Mar 03, 2020 8:49 pm

Remember that this is a brand new spanking wing. They need to envelope various stall and flutter data points of the wings before going on to other systems.

Note that some of the testing may involve more than just certification requirements but they may also collecting various data to be fed back into he simulators.

Wouldn'd be surprised that these advanced simulators require massive amount of data to validate the programing.

bt

bt
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Opus99
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Re: Boeing 777X Testing/Production Thread - 2020

Tue Mar 03, 2020 9:06 pm

https://twitter.com/JenSchuld/status/12 ... 24/photo/1
for those looking for an upper beacon light. there you go!
 
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keesje
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Re: Boeing 777X Testing/Production Thread - 2020

Wed Mar 04, 2020 12:17 am

Stitch wrote:
The likelihood of the Restoring Aviation Accountability act being made law before the 777X receives her Type Certificate is extremely unlikely considering how slow Congress moves. And even if it is somehow enacted before the completion of the 777X's current certification, having read the text of the proposed Act, the timeframes involved for the implementation of the 18 member aircraft type certificate review panel the act calls for and the quinquennial certificate review cycle means that the 777X would receive her certificate under current regulations and that the Act would then come into effect five years on when the certificate is up for review (or sooner if Boeing files for a Supplemental or Amended Certificate).


I think next to FAA, EASA and Emirates authorities were in the JATR mentioned as reference for the new Act. Confirming type certification without applying what they stated in the JATR report, seems highly unlikely for releasing Lufthansa and Emirates as launching operators of the 777-9. The Integral certification approach needs to be confirmed and demonstrated.
"Never mistake motion for action." Ernest Hemingway
 
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Stitch
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Re: Boeing 777X Testing/Production Thread - 2020

Wed Mar 04, 2020 3:32 am

keesje wrote:
I think next to FAA, EASA and Emirates authorities were in the JATR mentioned as reference for the new Act. Confirming type certification without applying what they stated in the JATR report, seems highly unlikely for releasing Lufthansa and Emirates as launching operators of the 777-9. The Integral certification approach needs to be confirmed and demonstrated.


There have been no reports that EASA and/or GCAA are requiring the 777X certification to adhere to the JATR recommendations. Nor have Lufthansa or Emirates been reported requiring the 777X to be certified incorporating JATR recommendations.

Everything published to date has pointed to the 777X being certified under current FAA, EASA and GCAA processes.
 
VV
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Re: Boeing 777X Testing/Production Thread - 2020

Wed Mar 04, 2020 6:45 am

It seems the second flight test article is almost ready to do the taxi test.
The first flight is very close now.
 
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BoeingVista
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Re: Boeing 777X Testing/Production Thread - 2020

Wed Mar 04, 2020 9:17 am

Stitch wrote:

Again, the 777X's flight level during testing has nothing to do with the static test failure.


And again, You don't know that
BV
 
VV
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Re: Boeing 777X Testing/Production Thread - 2020

Wed Mar 04, 2020 11:23 am

BoeingVista wrote:
Stitch wrote:

Again, the 777X's flight level during testing has nothing to do with the static test failure.


And again, You don't know that


But then the question is whether anyone can affirm with certainty the flight level of the test flights so far is related to the static test.

Basically, everyone is just throwing out
baseless opinion/speculation.

The only credible explanation is because they need to so some important basic tests with flaps/slats extended at different configurations and at different speeds.

As one poster said he/she has been following the flights using Flightradar24 and confirmed the characteristics of such suggested flight test profile.
 
Sooner787
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Re: Boeing 777X Testing/Production Thread - 2020

Wed Mar 04, 2020 3:27 pm

VV wrote:
It seems the second flight test article is almost ready to do the taxi test.
The first flight is very close now.


Great news........ I forgot, will Boeing be using 4 or 5 frames for the flight test program?
 
Opus99
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Re: Boeing 777X Testing/Production Thread - 2020

Wed Mar 04, 2020 3:53 pm

Sooner787 wrote:
VV wrote:
It seems the second flight test article is almost ready to do the taxi test.
The first flight is very close now.


Great news........ I forgot, will Boeing be using 4 or 5 frames for the flight test program?

4
 
georgiabill
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Re: Boeing 777X Testing/Production Thread - 2020

Wed Mar 04, 2020 5:34 pm

When is the first 779 scheduled to fly again? Hasn't been much news on recent flights.
 
VV
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Re: Boeing 777X Testing/Production Thread - 2020

Wed Mar 04, 2020 7:22 pm

georgiabill wrote:
When is the first 779 scheduled to fly again? Hasn't been much news on recent flights.


I guess they are doing some maintenance.

When you say maintenance on a flight test aircraft, it does not necessarily mean "maintenance".
First the scientists and engineers work hard to understand and process the data collected during the flights. There could be some adjustment to the Slat/Flap control unit and its software.
There could potentially be some physical adjustments to the high lift devices too like new gearing and other stuff.

There are also possible adjustment to the flight control system and its software based on the analysis results of the data collected during the flights.

Test flights are exactly to make sure you get the right aircraft configuration. It is a little bit useless to go "fast" and just fly to have some fun. It is a lot of paperwork, it is a lot of analysis and it is a lot of adjustments.

Be patient.
 
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Stitch
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Re: Boeing 777X Testing/Production Thread - 2020

Wed Mar 04, 2020 8:50 pm

Stitch wrote:
Again, the 777X's flight level during testing has nothing to do with the static test failure.

BoeingVista wrote:
And again, You don't know that.


But I do know that taking the frame to 35,000 feet - or even higher - is not going to bend the wings upward and the fuselage downward to the levels it did that generated the 149% load that induced the failure on the test article. It won't generate even 100% of that load. So therefore it cannot be the reason why Boeing has not taken the 777-9 to 35,000 feet altitude yet. Seriously, people, it's just common sense that there is no correlation.




I looked through the 787 flight test blogs and it reached a maximum altitude of 30,000 feet as part of it's Initial Airworthiness testing. I could not find a specific date on when this happened, but it was within the first 60 hours of flight testing and there was no mention of reaching that altitude during the first 24 hours of flight testing for either ZA001 or ZA002. It was mentioned that flights up to 30,000 feet were conducted as part of flutter testing.

Until the Type Inspection Authorization was received, the airframe could only fly with the pilot and co-pilot. Once that was received, engineers could be carried in the main cabin. That process was planned to take between two to three months for the 787.
 
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Re: Boeing 777X Testing/Production Thread - 2020

Wed Mar 04, 2020 9:36 pm

Stitch wrote:

Until the Type Inspection Authorization was received, the airframe could only fly with the pilot and co-pilot. Once that was received, engineers could be carried in the main cabin. That process was planned to take between two to three months for the 787.



I seem to remember that the Airbus flight crew for the first few flights was three - all in their emergency evacuation suits in case a quick exit was necessary.

Is two flight crew an FAA rule?
 
airnorth
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Re: Boeing 777X Testing/Production Thread - 2020

Wed Mar 04, 2020 9:37 pm

Stitch wrote:
Stitch wrote:
Again, the 777X's flight level during testing has nothing to do with the static test failure.

BoeingVista wrote:
And again, You don't know that.


But I do know that taking the frame to 35,000 feet - or even higher - is not going to bend the wings upward and the fuselage downward to the levels it did that generated the 149% load that induced the failure on the test article. It won't generate even 100% of that load. So therefore it cannot be the reason why Boeing has not taken the 777-9 to 35,000 feet altitude yet. Seriously, people, it's just common sense that there is no correlation.




I looked through the 787 flight test blogs and it reached a maximum altitude of 30,000 feet as part of it's Initial Airworthiness testing. I could not find a specific date on when this happened, but it was within the first 60 hours of flight testing and there was no mention of reaching that altitude during the first 24 hours of flight testing for either ZA001 or ZA002. It was mentioned that flights up to 30,000 feet were conducted as part of flutter testing.

Until the Type Inspection Authorization was received, the airframe could only fly with the pilot and co-pilot. Once that was received, engineers could be carried in the main cabin. That process was planned to take between two to three months for the 787.


In unrelated but similar news, the C- Series testing waited until test flight number 51, ( I think I added up all of the flights correctly, there is some room for error! ) before reaching FL 400. I had to read through a bunch of that testing thread, contributor Paolo92 was keeping pretty good records of all of the flight testing at the time.
viewtopic.php?f=3&t=1437935&p=22019053&hilit=airnorth#p22019049
 
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Stitch
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Re: Boeing 777X Testing/Production Thread - 2020

Wed Mar 04, 2020 10:11 pm

StTim wrote:
I seem to remember that the Airbus flight crew for the first few flights was three - all in their emergency evacuation suits in case a quick exit was necessary. Is two flight crew an FAA rule?


That I do not know. I am thinking that it might be a Boeing rule as the articles I read seemed to imply that Type Inspection Authorization might not have been an FAA milestone, but a Boeing one. It seemed to be that at this point, the general handling characteristics of the airframe were known to a point that they felt comfortable having more people aboard.
 
VV
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Re: Boeing 777X Testing/Production Thread - 2020

Wed Mar 04, 2020 11:49 pm

I think it still has "X" status (experimental) during flight test.

Basically they can do almost anything.
 
Delta350
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Re: Boeing 777X Testing/Production Thread - 2020

Thu Mar 05, 2020 5:14 am

Will the 777X be at the next Paris Air Show?
Plane Spotter from the Magic City and Hartsfield-Jackson...(ATL)
 
JohanTally
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Re: Boeing 777X Testing/Production Thread - 2020

Thu Mar 05, 2020 7:13 am

Delta350 wrote:
Will the 777X be at the next Paris Air Show?


This year it is the Farnborough air show in July. They alternate between Paris and Farnborough each year. Barring any catastrophic testing setbacks or the Covid-19 continuing to affect global travel and congregating in large groups, the 777X will be at the show possibly with the 737MAX10.
 
VV
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Re: Boeing 777X Testing/Production Thread - 2020

Thu Mar 05, 2020 7:37 am

Delta350 wrote:
Will the 777X be at the next Paris Air Show?

Since the next Paris airshow is in June 2021, there is a significant probability the 777-9 will be there.
 
Noshow
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Re: Boeing 777X Testing/Production Thread - 2020

Thu Mar 05, 2020 11:00 am

IIRC Airbus typically has four person crews on first flights: Two test pilots, one test engineer in the cockpit and one lead test engineer at the main console in the cabin. Later on they have more crew including engine engineers.
 
Opus99
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Re: Boeing 777X Testing/Production Thread - 2020

Thu Mar 05, 2020 12:06 pm

N779XX is online on Flight radar. It’s 12pm here in London but 4am in Seattle? That’s an early start

It’s gone off now
Last edited by Opus99 on Thu Mar 05, 2020 12:20 pm, edited 1 time in total.
 
mxaxai
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Re: Boeing 777X Testing/Production Thread - 2020

Thu Mar 05, 2020 12:08 pm

Stitch wrote:
Stitch wrote:
Again, the 777X's flight level during testing has nothing to do with the static test failure.

BoeingVista wrote:
And again, You don't know that.


But I do know that taking the frame to 35,000 feet - or even higher - is not going to bend the wings upward and the fuselage downward to the levels it did that generated the 149% load that induced the failure on the test article. It won't generate even 100% of that load. So therefore it cannot be the reason why Boeing has not taken the 777-9 to 35,000 feet altitude yet. Seriously, people, it's just common sense that there is no correlation.

Looking back to the A380 test campaign, they did Mmd, high altitude and flutter testing before the static load tests were all completed: https://www.flightglobal.com/a380-power ... 76.article

I don't think the failure is the reason for them to stay low; it is more likely either not yet necessary or engine / systems related. Remember that the engines got a redesign fairly recently and GE probably hasn't been able to redo all the tests and calculations yet.
 
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Re: Boeing 777X Testing/Production Thread - 2020

Thu Mar 05, 2020 3:13 pm

As to why they have not yet gone to high altitude, I for one am willing to believe that the Boeing test engineers and pilots know what they are doing. And if there is some deep, dark secret tied in with the static test failure I am quite sure it will not be revealed. But if there was, I do not believe they would be flying until it was fixed (which they may have already done). The long and short of it is there are plenty of tests to be done, some at low altitude and some at high. So Boeing has decided to do the low altitude tests first; so what?
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par13del
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Re: Boeing 777X Testing/Production Thread - 2020

Thu Mar 05, 2020 4:35 pm

What do we need to say about Airbus versus Boeing to move the dialog on the 777X testing beyond the fact that the a/c has not yet flown to 30k feet?
 
LilD350
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Re: Boeing 777X Testing/Production Thread - 2020

Thu Mar 05, 2020 5:50 pm

par13del wrote:
What do we need to say about Airbus versus Boeing to move the dialog on the 777X testing beyond the fact that the a/c has not yet flown to 30k feet?


Well I guess nothing much can be said about the two different aircraft programs...

It's just different people wondering how the progress of the tests is going... Since there's no activity on the 777X at the moment (last I checked), what else would be there to talk about but reflect about what's been going on?

I guess sometimes it's better to wonder about these things just to keep interest in the program... Obviously if the altitude thing keeps coming up that means a lot of people are wondering, and doesn't necessarily mean there's something wrong with the Boeing...
 
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kanban
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Re: Boeing 777X Testing/Production Thread - 2020

Thu Mar 05, 2020 5:56 pm

Airbus putting the crew in survival suits was as much PR as actually necessity. Boeing flies in shirt sleeves and I believe they have parachutes on the first flight. OSHA would like to see a separable cockpit section like the space shuttle that would beat the crew clear in the event if what ever. :duck:
 
smartplane
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Re: Boeing 777X Testing/Production Thread - 2020

Thu Mar 05, 2020 8:16 pm

Perhaps use the FOIA to discover if the FAA has imposed any testing limitations / restrictions on Boeing and/or GE relating to the 777X.

For a program so adrift of schedule, with a lot of cash flow locked in to supposedly firm orders, there seems to be surprising lack of urgency or impetus.
 
StTim
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Re: Boeing 777X Testing/Production Thread - 2020

Thu Mar 05, 2020 8:40 pm

smartplane wrote:
Perhaps use the FOIA to discover if the FAA has imposed any testing limitations / restrictions on Boeing and/or GE relating to the 777X.

For a program so adrift of schedule, with a lot of cash flow locked in to supposedly firm orders, there seems to be surprising lack of urgency or impetus.


In my view testing is already taking place at a good rate. There will be days when the test frame does not fly. It will need close inspection in areas and reconfiguration for the next set of tests.

Also testing is best not rushed such that things can be missed.

Rarely will a schedule drift be recovered in testing.
 
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Stitch
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Re: Boeing 777X Testing/Production Thread - 2020

Thu Mar 05, 2020 10:01 pm

smartplane wrote:
For a program so adrift of schedule, with a lot of cash flow locked in to supposedly firm orders, there seems to be surprising lack of urgency or impetus.


One could argue the same looking at the 787 Flight Test and Certification program, and that had significantly more cash flow locked into it.
 
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Re: Boeing 777X Testing/Production Thread - 2020

Thu Mar 05, 2020 10:14 pm

I can't understand the sense of urgency with wanting the test program to be progressing at a much faster pace. Wasn't it a major complaint of people on this site that the MAX was rushed into service without adequate testing. I'm of the belief that if Boeing wants to take the dear sweet time on the 777X testing program, let them. There is a sense of urgency, urgency to get it right the first time. Boeing can't withstand another MAX debacle.
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bikerthai
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Re: Boeing 777X Testing/Production Thread - 2020

Thu Mar 05, 2020 10:30 pm

All,

Just to let you know, the sense of urgency of flight testing may be taking a back seat in Seattle.

The cornavirus has started to impact operations and many companies (including some Boeing facilities) have asked those who can work remote to do so.

https://www.foxnews.com/us/washington-k ... -from-home

Public Health officials in King County on Wednesday recommended that businesses allow their employees to telecommute throughout March in an effort to reduce the amount of face-to-face contact between large numbers of people during this “critical period” in the COVID-19 outbreak.

bt
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enzo011
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Re: Boeing 777X Testing/Production Thread - 2020

Thu Mar 05, 2020 11:09 pm

AAlaxfan wrote:
I can't understand the sense of urgency with wanting the test program to be progressing at a much faster pace. Wasn't it a major complaint of people on this site that the MAX was rushed into service without adequate testing. I'm of the belief that if Boeing wants to take the dear sweet time on the 777X testing program, let them. There is a sense of urgency, urgency to get it right the first time. Boeing can't withstand another MAX debacle.


I think the reason for the sense of urgency on here is that we are getting mixed messages on the 777X program. It wasn't long ago that Boeing was still talking about a flight test program of less than one year. In their second quarter earning in July last year they confirmed the first flight would slip into 2020 while still targeting EIS in late 2020.

While the company is still targeting late 2020 for first delivery of the 777X, there is significant risk to this schedule given engine challenges, which are delaying first flight until early 2020.


Boeing Reports Second-Quarter Results

As for the comparisons with Airbus programs, while there isn't much we can take from the way Airbus did theirs we also only have the A350 recently to compare to to see how it is progressing. The A350 took just over a year to complete all of its flight testing so the time frame is close to what Boeing was aiming for. With the 787 Boeing aimed at less than 9 months and they missed spectacularly so I don't think comparisons with the 787 will help other than to look at it negatively. So while I don't think we will learn much by trying to compare the two programs side by side (for a day to day or flight to flight comparison), it does make you wonder why it is taking so long (apparently) to get to a high altitude for the 777X.

I think it is most likely that there is nothing to see and all is going to plan, but seeing that Boeing was eager to go beyond the already stringent certification process when the structure failure happened, it would be strange when they didn't have the same attitude when it came to the flight tests as well. It may not be needed to get up to above 30 000 ft right now, but if all is well and progressing as planned why not try to shorten the flight tests by opening up the flight envelope early, especially if you are on a tight schedule already?
 
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Re: Boeing 777X Testing/Production Thread - 2020

Fri Mar 06, 2020 3:13 am

kanban wrote:
OSHA would like to see a separable cockpit section like the space shuttle that would beat the crew clear in the event if what ever. :duck:

That isn't any guarantee ( ref: https://www.youtube.com/watch?v=TN-mXzAFCqM which is worth the hour and a half to watch... ).
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VV
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Re: Boeing 777X Testing/Production Thread - 2020

Fri Mar 06, 2020 7:30 am

enzo011 wrote:
...
It may not be needed to get up to above 30 000 ft right now, but if all is well and progressing as planned why not try to shorten the flight tests by opening up the flight envelope early, especially if you are on a tight schedule already?



I have the feeling people think the "flight envelope" is somekind of big brown paper envelope that is hard to open with a pair of scissor.

The reality is that you just need to fly into it. Flying and aircraft takes time. For instance the climb can take up to 30 minutes then you flight a more or less level flight and then you descend and land.

One flight is one cycle lost and several hours lost. Knowing that one hour of test flight costs about US$ 120,000 then you do not want to waste money and time when it is not necessary. Please note that the 120 thousand dollars is all inclusive and not just the fuel.

The most difficult part of flight test is NOT flying the aircraft. It is about getting the right data to confirm or to adjust the mathematical model of the aircraft. It also allows to check or adjust all kind small things like slat/flap angle setting, define the different stall speeds with all the final high-lift configuration. The biggest part of flight test is the "low-speed" part (take-off and landing). The other big chunk is calibrating the handling characteristics of the aircraft and then adjusting the flight control system.

Flying at high altitudes is done with clean configuration. Basically you are only getting "high-speed" data like specific air range. It is more about having the efficiency of the aircraft. There is nothing to adjust to the aircraft. If the high-speed performance is not good at that stage, it is already too late to do anything anyway. You need to wait until the next iteration of high-speed aerodynamic iteration.

I just do not understand why so many people are obsessed of flying to 30,000 ft or above when it is just about flying.

We need to understand "Opening the flight envelope" to higher altitude is just flying into it. It is not a kind of tight think and hard brown envelope to cut with a tool.
It is not because you can do it that you should do it.
It is about saving time and money and doing the right thing at the right time.

This recurring question about flying at high altitude during early test flight campaign is so irrelevant that I start to ask question about what those people really have in their mind.
 
Noshow
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Re: Boeing 777X Testing/Production Thread - 2020

Fri Mar 06, 2020 8:25 am

When is No. 2 due for first flight please?
 
planecane
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Re: Boeing 777X Testing/Production Thread - 2020

Fri Mar 06, 2020 1:04 pm

Not specific to the 777X but is there any record of the highest percentage of expected load any aircraft has ever experienced in flight?

Basically, how much margin over the worst case scenario is the 150% requirement providing?
 
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enzo011
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Re: Boeing 777X Testing/Production Thread - 2020

Fri Mar 06, 2020 1:25 pm

VV wrote:
I have the feeling people think the "flight envelope" is somekind of big brown paper envelope that is hard to open with a pair of scissor.

The reality is that you just need to fly into it. Flying and aircraft takes time. For instance the climb can take up to 30 minutes then you flight a more or less level flight and then you descend and land.

One flight is one cycle lost and several hours lost. Knowing that one hour of test flight costs about US$ 120,000 then you do not want to waste money and time when it is not necessary. Please note that the 120 thousand dollars is all inclusive and not just the fuel.

The most difficult part of flight test is NOT flying the aircraft. It is about getting the right data to confirm or to adjust the mathematical model of the aircraft. It also allows to check or adjust all kind small things like slat/flap angle setting, define the different stall speeds with all the final high-lift configuration. The biggest part of flight test is the "low-speed" part (take-off and landing). The other big chunk is calibrating the handling characteristics of the aircraft and then adjusting the flight control system.

Flying at high altitudes is done with clean configuration. Basically you are only getting "high-speed" data like specific air range. It is more about having the efficiency of the aircraft. There is nothing to adjust to the aircraft. If the high-speed performance is not good at that stage, it is already too late to do anything anyway. You need to wait until the next iteration of high-speed aerodynamic iteration.

I just do not understand why so many people are obsessed of flying to 30,000 ft or above when it is just about flying.

We need to understand "Opening the flight envelope" to higher altitude is just flying into it. It is not a kind of tight think and hard brown envelope to cut with a tool.
It is not because you can do it that you should do it.
It is about saving time and money and doing the right thing at the right time.

This recurring question about flying at high altitude during early test flight campaign is so irrelevant that I start to ask question about what those people really have in their mind.



People have it in their minds because the previous program that was close to the timeline that the 777X is aiming for was already up high at this stage. Now this doesn't mean anything because we don't know what they are testing or their schedule. This will not stop us speculating because that is what we do, we ask questions even if the answer is most likely that nobody knows.

Until the aircraft goes higher in altitude the questions will be asked. I think for most there is nothing more than just curiosity around it and wondering out loud.
 
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Re: Boeing 777X Testing/Production Thread - 2020

Fri Mar 06, 2020 1:53 pm

planecane wrote:
Not specific to the 777X but is there any record of the highest percentage of expected load any aircraft has ever experienced in flight?

Basically, how much margin over the worst case scenario is the 150% requirement providing?


As it suggests - 50%. The 100% figure is supposed to be the largest load the plane would ever see in operation.
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planecane
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Re: Boeing 777X Testing/Production Thread - 2020

Fri Mar 06, 2020 2:11 pm

scbriml wrote:
planecane wrote:
Not specific to the 777X but is there any record of the highest percentage of expected load any aircraft has ever experienced in flight?

Basically, how much margin over the worst case scenario is the 150% requirement providing?


As it suggests - 50%. The 100% figure is supposed to be the largest load the plane would ever see in operation.

What I mean is has any aircraft ever experienced forces over the design max load in flight that has been documented?
 
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Re: Boeing 777X Testing/Production Thread - 2020

Fri Mar 06, 2020 4:26 pm

planecane wrote:
scbriml wrote:
planecane wrote:
Not specific to the 777X but is there any record of the highest percentage of expected load any aircraft has ever experienced in flight?

Basically, how much margin over the worst case scenario is the 150% requirement providing?


As it suggests - 50%. The 100% figure is supposed to be the largest load the plane would ever see in operation.

What I mean is has any aircraft ever experienced forces over the design max load in flight that has been documented?

There have been planes that have broken up in flight. There have also been planes that have seen so much stress in flight that they have been permanently distorted. Either extreme weather or pilot mishandling is capable of over stressing an airframe way beyond its design loads. But it is very rare. The point is that it is impossible to predict the maximum load an airframe can see, and hence it is impossible to build one that will never fail. But with over 100 years of experience engineers have been able to predict the loads that an airframe will see when operated properly while avoiding extreme weather. And weather radar and other tools has also improved to the point where avoiding extreme weather is always possible.
The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
 
airnorth
Posts: 457
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Re: Boeing 777X Testing/Production Thread - 2020

Fri Mar 06, 2020 5:12 pm

planecane wrote:
scbriml wrote:
planecane wrote:
Not specific to the 777X but is there any record of the highest percentage of expected load any aircraft has ever experienced in flight?

Basically, how much margin over the worst case scenario is the 150% requirement providing?


As it suggests - 50%. The 100% figure is supposed to be the largest load the plane would ever see in operation.

What I mean is has any aircraft ever experienced forces over the design max load in flight that has been documented?


I assume China Airlines Flight 006 would qualify as a flight that exceeded design max loads. This plane did suffer structural damage with the wings were permanently bent, but it was repaired and returned to service.

https://en.wikipedia.org/wiki/China_Airlines_Flight_006
 
pugman211
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Re: Boeing 777X Testing/Production Thread - 2020

Fri Mar 06, 2020 5:16 pm

planecane wrote:
scbriml wrote:
planecane wrote:
Not specific to the 777X but is there any record of the highest percentage of expected load any aircraft has ever experienced in flight?

Basically, how much margin over the worst case scenario is the 150% requirement providing?


As it suggests - 50%. The 100% figure is supposed to be the largest load the plane would ever see in operation.

What I mean is has any aircraft ever experienced forces over the design max load in flight that has been documented?



Wasn't there a brand new KC135 or C160?? That had an inflight mishap and was wrote off because of the stress loads once?
 
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bikerthai
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Re: Boeing 777X Testing/Production Thread - 2020

Fri Mar 06, 2020 5:48 pm

airnorth wrote:
I assume China Airlines Flight 006 would qualify as a flight that exceeded design max loads.


This would be an example of the frame exceeding limit load or 100% load.

Airframe break-up would be 150%. Not sure if this has ever occured as the only scenario I can see this happen is the plane trying to come out of a steep dive.

I believe hard landing is typically where you'll find he most occurrence of exceeding limit load.

bt
Intelligent seeks knowledge. Enlightened seeks wisdom.
 
Opus99
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Re: Boeing 777X Testing/Production Thread - 2020

Fri Mar 06, 2020 7:11 pm

https://twitter.com/boeingairplanes/sta ... 69632?s=21

New Boeing Official Photos of the 777x
 
Opus99
Posts: 990
Joined: Thu May 30, 2019 10:51 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sat Mar 07, 2020 9:26 am

https://www.airlineratings.com/news/fab ... 7x-flight/

A Boeing spokesperson says that the 777X in a planned maintenance period of installing and calibrating test equipment to support the next phase of testing.

They also say the 777x is performing “well”
 
Noshow
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Re: Boeing 777X Testing/Production Thread - 2020

Sat Mar 07, 2020 9:35 am

Gear up!
 
flipdewaf
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Re: Boeing 777X Testing/Production Thread - 2020

Sat Mar 07, 2020 9:41 am

Opus99 wrote:
https://twitter.com/boeingairplanes/status/1235996105881669632?s=21

New Boeing Official Photos of the 777x

Phwooooaaarrrrrrr!


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Image
 
mxaxai
Posts: 1905
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Re: Boeing 777X Testing/Production Thread - 2020

Sun Mar 08, 2020 11:30 am

bikerthai wrote:
airnorth wrote:
I assume China Airlines Flight 006 would qualify as a flight that exceeded design max loads.


This would be an example of the frame exceeding limit load or 100% load.

Airframe break-up would be 150%. Not sure if this has ever occured as the only scenario I can see this happen is the plane trying to come out of a steep dive.

I believe hard landing is typically where you'll find he most occurrence of exceeding limit load.

bt

Even jets like Egypt Air 990 or Atlas Air 3591 didn't exceed their ultimate load, at least not simply by pulling up. The Atlas Air 767 'only' pulled about 4 G. The main reason for the 150% requirement is to account for lower strength due to manufacturing tolerances, calculation errors and undetected fatigue.
 
Noshow
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Joined: Wed Jun 15, 2016 3:20 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sun Mar 08, 2020 1:51 pm

Guys are you aware how boring it is to see this topic get spoiled with your idle chatter?

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