No, cycles to a 777 are the same as to an A320. Both have limits of validity to 60,000.http://www.boeing.com/commercial/aeroma ... 2012_q4/2/
The 787 has a fractionally better life. This isn't a 747 with only 35,000 cycles. IIRC, Airbus widebodies have a 36,000 cycle LOV. Anyone have a link? What is the A350 cycle life?
Boeing knew the Japanese airlines would use the 787 and 777 as if they were narrowbody aircraft, so they are built to take the duty for 20+ years.
Late edit:. I need to emphasize the 787 and 787 have the same cycle lives as the E-jets, A320, and the CRJ at EIS. (CRJs now 80,000 cycle LOV with the latest PIPs, just as the A320 grew from 48,000 to 60,000, excludes the A320-100 due to later structure changes).
You seem to be saying that Boeing put structure into aircraft only needed by a fraction of the aircraft sold. This doesn`t sound like "driving 787 costs down to unprecedented levels" Boeing. Would it not be better to say that Boeing test their widebody aircraft to this number of cycles and Airbus have not done this yet. There is nothing preventing Airbus from doing this and it is possible JAL only bought the A350 with contractual guarantees to provide aircraft tested and certified to this level. They did it with the A320, can they not do the same with the A350?
Also I have heard it said by a respected poster on here that the majority of modern widebodies will be retired on economic reasons long before they reach there cycle life. I wonder who that was?
I was referring to the Japanese widebodies specifically; so I'm not contradicting that the majority of widebodies will be retired early. Few will reach 30,000 cycles last I looked.
I'm shocked the 777 and 787 are certified for so many cycles. I know in the 777 there is structure in there that shouldn't be. The joints had far too much weight to be able to meet that certification. It isn't just performing the test, an aircraft is designed for the cycles.
In the case of barrel CFRP construction, cycles are cheap. It is my favorite design for aircraft because added cycles are free. I see the posts by Leeham that panel and barrel construction are the same weight and efficiency. They are, up to about 36,000 cycles. Above that, barrel construction (and this is just my opinion) gives more cycles for free.
As to extending cycle life on the A350, I do not know. What I know about the A320:
1. Structural changes after the -100, including required reinforcement (weight added that was part of the sharklet kit) to go from 48,000 to 60,000 FC.
2. Airbus attempted to go to 90,000 FC/180,000 FH but failed. I am not in the know as to why the testing showed this goal wasn't achievable.
Yet we see 737NG going through bulkhead repairs due at 85,000 FC.
I cannot find the A350 certified life. The current online document just notes the current life is temporary as testing isn't complete (normal at this early in service) and no problems have been found:https://www.easa.europa.eu/sites/defaul ... -09-26.pdf
I didn't see the new HGW update FWIW. If I missed due to poor searching, please let me know.
There will be a trade between cycle life and MTOW/MLW/MZFW; increasing any one reduces cycle life. For example, the 777F has a lower cycle life than the 777L due to greater allowed. Will Airbus split their certification as Boeing did for the 777-200 (w/GE90-110s)? That is possible.
I can only go off what is known and that is the 787 has the highest certified cycle life of any widebody. Only the other Boeing products come close. If an airline puts the A350 into domestic duty, the maintenance plans are currently for long haul and thus would be expensive on a per cycle basis. To modify the plans takes years of testing, diagnosing the faults found and needed inspections and repairs.
For example, on the A320 going to 60,000 cycles, they found a bit of minor cracking (this is normal), so new build planes have redesigned structure (minor redesign, little fillet changes that actually saved weight) while current aircraft being maintained for 60,000 cycles/120,000 flight hours must add a trivial number of doublers and add certain bracket inspections.
Airbus has yet to invest in that. It costs $20 million to $30 million to do so.
It also takes designing the aircraft to about 3% lower stress limits. So the question is, where did Airbus go to the limits? I would speculate only on the A350-900LR. But as I'm neither a structural engineer nor employed on the A350 project... But it also takes having the nacelles/pylon designed for that many cycles. Boeing levied such a requirement on the 777 and 787 to vendors. Did Airbus? Since at 30,000 cycles the engines/nacelles are over half the aircraft value, no one is going to replace them at that juncture as two new sets are worth more than the whole widebody.
But, we are debating a tiny number of widebodies. Few airlines fly widebodies on sub 4-hour missions anymore and usually only if they need to do so for pilot training due to so many missions for the fleet are 8+ hours (SQ A350 operations come specifically to mind) or for domestic premium demand (e.g., LAX-DFW on AA or other similar routes) and aircraft fleet repositioning.
So I believe we are in agreement. But because the Japanese airlines keep buying Boeing widebodies for domestic duty, Boeing keeps designing for far more cycles than I would design a widebody for. There is a weight penalty for the 787 that is well over a ton. That is a 100nm+ range penalty for the 787-10 to meet two customers' demands.
I believe the A350 will sell incredibly well. I also believe the A321NEO/-10 MAX have killed 90%+ of the widebody short haul market as they are better economic choices for *most* airlines (JAL and ANA really are the only exceptions that come to mind).
As already noted, the 787-10 isn't a great plane for over 6,000nm (still air) missions. Meh... I personally believe the A350 should be selling better than it has but that Airbus' C-suite did an epic sales flop by not increasing production further to free up short term slots. Boeing took a gamble with ramping to 14/month that is paying off. Airlines have never wanted to wait as long as manufacturers would make them wait for aircraft.
The 787-10 also weighs 8.5 tons less empty than an A359. Why would an airline buy that plane for short haul? Look into why EK chose the 787-10 for mid-haul. https://leehamnews.com/2017/11/15/emira ... gs-787-10/
What that article dismisses is that electrical subsystems have much lower maintenance costs per cycle than the more conventional subsystems of the A350. Until you fly past 4,000nm, there is a significant cost savings flying the 787-10 over the A359. I calculate about $1,000 per day. That cost advantage disapears rapidly and is (by my estimate) by 5,250 nm. While the 787-10 can be flown further, the higher wing loading and less optimized for cruise engines are hurting the economics if an airline pushes out to the 6,000nm range (all ranges still air). After 6,000 nm, only the 777X can compete with the A350 family. (Sorry A380 and 77W, your era is now over.)
An airplane just simply cannot be everything. The 787 certainly isn't. This is why I quantify which markets it is great at. When I work on widebody design concepts, we choose what mission we will be the best at and what mission is the corner case. One then selects sub-systems and technology to put into the aircraft to meet that business case. Now, most of what I worked were 'paper airplanes' that never were launched.
But some were and I can see my concepts in the A320NEO.
But more by my friends Steve and Steve.
(Last names withheld to protect the guilty.)
1. For example, I worked a widebody optimized for minimum cost at 4,000nm (TATL), but with 7,400nm range. This could do TPAC and EU to ASIA, but was for EU airlines going TATL and the ME3.
2. I also worked a widebody with minimum cost at 5,500nm and 7,500nm range. (Super optimized for EU to Coastal Asia and great on TPAC). The ME3 estimate on sales was cut 75%...
The later design had a cycle life of 20,000 FC less, but 20,000 FH more and weighed 3 metric tons more empty (larger wing area and higher bypass ratio engines). For 4,000nm to 5,500nm, the two really didn't have that much of a cost difference, but for the *same* body/cockpit/cargo, the wings, gear, and engines were different. Airbus obviously went through door #2 for the A350. Boeing went through door #1 for the 787. Meh... that decision must be made before program launch as it drives everything.
The easiest way to understand is that comparing the same MTOW, if the A359 MTOW is caped to the 787-10 MTOW, the A359 has less range. This isn't it being less efficient, it is the weight of the better wing and engines preventing fuel load (see the Leeham link above); this is a quick check between two such compatible airframes on which design door they went through. And yes, there aren't two doors, there is a spectrum. e.g., I worked a door#2 Airbus program that would found switching the engines to a door #1 optimization saved $1 million per aircraft in build costs as one technology could only be scaled to a certain engine size (at that time, technology has moved on). So Airbus shifted gears to a door #1.5 (ish) design (up 10,000 FC, same FH, same wing area and fuel, but door #1 engines with more structure for more short flights). It was because that one technology saved not only $1million per airframe in engine build costs, but it also saved $300/day in fuel which exactly matched the $300/day in costs the added FC and smaller engine diameter imposed on costs, so a free #1.5 trade which isn't common).
So do realize anything I write has a 'born on date.' I (and my employeer) were caught flat footed in how fast 3-D printing cuts costs. For the same work we have a quarter of the titanium 3-D printers Boeing does.
We will be 1 to 2 years behind in cost/weight savings behind Boeing because of that. sniffle. https://www.engadget.com/2017/04/11/boe ... etals-787/
But the high titanium/Barrel construction of the 787 gives more cycles for free. Meh, for most airlines they will not care. The 787 is certified for LOV of 66,000 cycles and 200,000 FH. I'll be shocked if any are flown beyond 50,000 FC or 150,000 FH. (As an enthusiast, I hope to be proven wrong), with most not breaking 30,000 FC IMHO (within A350 certification).
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