Before the newest update, my 777-300ER can fly for 25 hours at 0.85 speed. Now, it flew 17 hours and crashed, giving me violations out of nowhere. On the same route.
Were the flight ranges of the aircrafts changed?
If so, could you comment on the new limits under 0.85/0.80 speed?
I doubt all elements for the flight were the same, I assume you put the same fuel in, but was your climb the same? The wind will likely have changed as well which would be a huge factor!
Wind won’t change duration aloft. It affects range (how much less or more the wind carries you). But given same power settings and engine operating conditions, fuel burn doesn’t know what the wind is doing.
The 77E and 77W in IF used to fly for 25 hours, and 77L for 29 hours, at M0.85. I have been flying like this for 4000 hours (so yeah, no doubt it can reach 25hrs). I always use +2800ft/m and FL320 cruising.
I just did a flight with the 77W last night with my fuel numbers which were calculated before the update and everything proceeded normally. I’m more inclined to think this is just some pilot error but I will test it out.
Just checked out all my numbers for FL320. They have not changed at all. There are fluctuations of maybe +/- 100 lb/hour but obviously this is not enough to cause an 8 hour drop in range.
So, here are the theories I can come up with:
Flying with flight spoilers: reduction to ~ 15:30
Flying with flaps 5: reduction to ~ 19:40
AP set to 0.87: reduction to ~ 17:10
Rapid wind change induced stall, obviously not a reduction but could be a cause.
Turbulence induced stall (very unlikely) but could be a cause.
Don’t really want to call out OP for making a mistake but I don’t think the fuel profile has been touched.