zeke wrote:mintxwb wrote:And the DOW you flew is not higher than 141.7 tonnes on long-haul missions? When you use your software to produce 325 seats, 268t, 8100nm, what is the DOW you use, the same as 141.7t?
We would have over a dozen different DOW configurations on the A350 depending on the sector, the DOW is not directly presented to us in the cockpit, just the ZFW. For me to work out the DOW I would need to lookup the configuration for the flight and add that to the basic weight.
I have already corrected someone earlier on this to say it was 315 seats not 325. That was the 268 tonne 3 class configuration.
This is not my software, it is the certified software loaded on the aircraft. It is used for real world performance calculations from takeoff to landing.
I am not going to say the DOW, as previously stated the fuel burn is confidential information. If I told you the DOW you know the fuel fraction, ie TOW-DOW.
All I will confirm it does not need the full 268 tonnes to do it, there is an additional margin for fuel reserves.
however the math I provided does not support your assertion that the 359/268 can move 315 8100nm. it appears to be discrepant from what your software is providing as an output. in most cases this will be operator error. either way i'd like to understand why basic PR chart math seems to produce results that are hours apart from what you say a computer literally on the plane is producing.
I have the ulr at [email protected], bearing in mind it is a ton or 2 light because of the cargo hold deactivation. the std 280t should hit 7500-7600 in revenue service with a real airline. if your cabin matches airbus and your pax+bags are 95kg, then their own ACAPS says 8100 with 325 at 280t. That's 12t more fuel than you say your computer is showing.
For one case on May 27:
https://www.flightradar24.com/data/flig ... 7#20a985e2
https://flightaware.com/live/flight/PAL ... /KJFK/RPLL ),
Although the route is close to GCD (7574 NM), the on-air flight duration was 16:56. Almost 17 hours.
This is obviously because the plane met a very strong headwind; the ground speed was 380kts at one point. (I don't have FR24 paid access to the true airspeed data)
As PAL has not required a technical fuel stop or declared fuel emergency since they started this route,
the evidence is sufficient to conclude that 278t MTOW A359 with 35.6-37.1t payload (2018 US BTS data) can fly up to 17 hours.
that was just one day tho. they'd have blocked seats. UAL was doing lax-sin for months and the plane didn't have the range necessary to make it work consistently.
I think one of the issues here is a mismatch between esad and city-pair range. frequently people mix those up in the discussions. the 359 is a good match for a city pair in the mid 7000s still air range. the 789 right about the same. the 89 is flying 17.5 hrs on ua101 *routinely*. the flight in the air right now is listed at 17:20. This is in UA trim. still air on that is only 7454. but at 17:20, it's pushing it a lot further. unless they're at M.84 for a ton of the flight, which having flown that route I personally did not see nor have I noted frequently in looking up 789 flights.
does that mean that the 789's 7635 spec is "unrealistic"? No. It's useful only for an estimate at about spec people over a city pair at about 7635 apart.
max endurance for 359 flights right now is 17 on a bad day (pr127, sq31). pr is at 278t flying with -3t pax vs spec. sq 275 but sq flies -7t pax vs spec.