the A380 might have been a winner had the 747 not been there but the 747-400 already was worldwide. Did they expect airlines to replace them 1:1? There were fewer 747-400's produced than most people realize. If you look at all 747-400 models ( passenger, freighter and combi's), the total production...
Jump to postGSOtoIND wrote:Also, did Boeing keep the old horizontal stabilizer on the 777X?
jagraham wrote:OldAeroGuy wrote:zeke wrote:
Not bad if the advertised 10% TSFC improvement over the GE90-115 is being met.
add a little more fuel burn for the larger diameter, but agreed.
GE Aviation’s GE9X, the largest aircraft engine yet developed, has received FAA certification at September 25th 2020, marking a major step toward entry-into-service on the Boeing 777-9, the first of the 777X family, in 2022. See : https://aviationweek.com/aerospace/aircraft-propulsion/ge9x-engine-b...
Jump to postThe 777 Classic has double slot inboard flaps. The outboard flap is single slot. It has a design heritage related to the 767. Reduction of flap slots helps approach noise by reduced landing flap drag (less thrust required) and less airframe noise (slots whistle). As Starlionblue describes, using the...
Jump to postAirbus toyed with a single deck design during the early stages of A380 development. The basic idea was two A330/A340 fuselages next to each other for a double bubble. It would have been over 11 meters wide, compared to the A380s 7.1 meters. IIRC, modeling showed that this would have been aerodynami...
Jump to postSomewhere in my bookshelf I have a newspaper cutting (from the UK's "Guardian") showing an artist's impression of the 757. It was, in fact, a Rolls Royce advertisement declaring, "The RB211-535 has just taken off!". The 757 had two underwing engines, a T-tail, and the complete 7...
Jump to postikramerica wrote:Looks about the same as the 772. One knock against the 773 is they kept the door spacing which makes placing premium seating awkward.
Is it made of cast iron? The 777LR and 777-300ER have the same 347-351t MTOW. Empty weight difference is 22,700kg and the fuselage is 10.1m longer. That is 2,247kg per metre of fuselage. The 777-200ER and 777-300 have the same 297-299t MTOW. Empty weight difference is 22,430kg. That is 2,220kg per ...
Jump to postNope, 2L will the 777-9 primary loading door. Door and engine geometry were carefully considered to allow adequate loading bridge clearance.
777-9 Door 2 placement allows for a more efficient seating arrangement than prior 777 models.
Opus99 wrote:VCVSpotter wrote:777-9 N779XX filed MWH-BFI 9:12AM - 9:42AM as BOE2.
https://flightaware.com/live/flight/BOE ... /KMWH/KBFI
Today’s flight is testing the autoland system
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...
Jump to post[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
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...
Jump to post777-9 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...
Jump to postMax Q wrote:Was the triple the first Jet transport with a completely circular fuselage?
Dmoney wrote:A330 and A350 are built so that 8&9 abreast is the only reasonable layout and perfectly fine.
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 ...
Jump to postBased 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...
Jump to postBased 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...
Jump to postYes. 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...
Jump to postAirKevin wrote:..... I remember right, the bacon lights were made more aerodynamic.
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.
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...
Jump to postBoeing 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...
Jump to postBoeing 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...
Jump to postI'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? ...
Jump to postAccording 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 ...
Jump to post25.123 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...
Jump to postThere 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...
Jump to postGiven 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...
Jump to postThe 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 ...
Jump to postI believe a 25% improvement in takeoff performance for h. tail fuel is very optimistic.
Jump to postWhy 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...
Jump to postNot 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...
Jump to postNot 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...
Jump to postOut 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 ...
Jump to postJup! 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...
Jump to postCongratulations 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...
Jump to postWas 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...
Jump to postI 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...
Jump to postThe 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...
Jump to postOh 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...
Jump to postThe 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...
Jump to postpatrickjp93 wrote:The 757 lacks a supercritical wing
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...
Jump to postI 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...
Jump to postpatrickjp93 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.
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.
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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