strfyr51 wrote:BNAMealer wrote:They need a newer fleet in the 130-145 seat range. Don’t really care if it’s A220 or MAX 7 as long as it can be flown to smaller markets.
One other thing you need to keep in mind, WN does LOT of takeoff and Landing cycles on their airplanes and they'll need a fuselage and Landing gear combination to work with those conditions. Now? Whether Boeing or Airbus build such a robust and rugged fuselage/landing gear combination in the future? will go a long way toward securing a new model order from WN. Of that you can bet. The 737 is proven to be a high cycle tolerant Airframe. Airbus can do Hi cycles but it isn't necessarily built for it.. which is why many more 737's will eventually be in Freighter service in the coming years..
It isn't just the gear. That can be rebuilt. It comes down to how many cycles can the airframe be certified for. Almost all airframes are not certified for their design capability. For example, the A320 was certified initially for 48,000 Flight cycles (FC) and 60,000 flight hours (FH). LH retired one at just over (going from memory) 57,000 FC. Add a few brackets on any after the initial build and that became 60,000 FC and 120,000 FH. The CRJs started at 60,000 FC, 90,000 FH and are now certified for 80,000 FC and 120,000 FH with a few past the initial 60,000 FC.
The A220 is certified for 60,000 FC and 90,000 FH. (C-checks now at 10,000 hours or 3 C-checks per HMV * 3 HMV for planned=90,000 FH).
Link on cycle testing (tested to 180,000 cycles to prove good for 60,000):
https://www.iabg.de/en/news-events/deta ... 00-fluege/Notice they were testing to determine residual strength. That means Airbus has the data to know if they can go for more (possibly with either making parts more flexibly are putting in doublers to strengthen parts a la A320 which did both).
https://en.wikipedia.org/wiki/Airbus_A220A CFRP wing is not the limit on cycles nor hours, so unless there is a weak link, the A220 should be certifiable for far more hours and more cycles. Then again, I thought that about the a320 getting to 90,000 FC and 180,000 FH and it failed (by a method on cycles). We had a thread on that:
viewtopic.php?t=775787Ok, a long answer that I agree WN needs a durable plane. Since they have done the 85,000 FC bulkhead repair (going from memory) on the 737, but don't tend to keep them aircraft not too much longer... I think 90k cycles is required.
But look at that lovely cycle testing. Ugh... I thought only 2X cycles were required (3X is easy to prove "good enough" even if the plane turns to dust 1 cycle later...). So this could be a paper exercise (mind you, a large team of stress engineers working for years) to extend to 90,000 cycles for the A220.
Anyone have a copy of AC120-104 handy? That is the regulation, I'm just not willing to pay $60 to get a copy for the fun of it.
But the A380 only tested 47,500 cycles to certify for half that. So there is precedence.
https://www.airbus.com/newsroom/press-r ... -a380.htmlSo this begs the question, the fatigue testing also does accelerated hours testing. I haven't been able to find any A220 reference on how many simulated accelerated hours were tested. But I am of the opinion Bombardier did enough testing to increase the limit of validity of the
C-series A220 to 90,000 cycles. I assume they kept the 2:3 ratio so 135,000 FH, but that is only my guess. That is more than sufficient for WN.
Now to divert a team of about 40 stress engineers (including a competent set of technical leads under a director) to plow through the data for 3 or so years...
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