So I decided to do some testing on the a330-300 and I realized that the a330 starts burning more fuel passing 10,000 feet while my power setting remains constant. This seems weird to me because I thought when a constant power setting is met with increasing altitude, fuel flow (fuel burn) decreases. I made sure that no A/P setting besides heading and vertical speed was engaged, which was manually controlled by me. Could this be the same case for the a330-900? I don’t remember seeing any behavior like this with other planes in IF.
I’d say it closely follows the normal a330 procedures designated by IF. I don’t see a problem with that. I’m maintaining my VS based on speed. I’d say it’s not a problem there.
I have heading and v/s to show I’m manually controlling. I’m climbing, so I’m showing how the fuel burn is going up while I have not changed any power settings. It should go down when I climb higher.
This is certainly weird but in the grand scheme of things I don’t think it affects anything too critical. The two A330s already have two of the limited reasonable fuel curves in this game anyways so let’s not touch them.
Try out your trim down to lower the nose, it’s my rule of thumb when climbing. When I’m a few thousand feet from cruise I put my nose trim to 0% and let the VS keep the nose up. Also try climbing slower, I’ve used the A330 for 8-9 hour flights with little to no problems.
Unfortunately, trim and rate of climb, won’t exactly fix this issue as I’m worried about the burn. The fuel flow is dependent on power, altitude, or a combination of the two. With a slower climb, you may be suggesting I use a lower climb power for flight, but this doesn’t fix the issue because my climb power is still constant. This means altitude would have to be the factor, and the fuel flow still goes up with altitude, which is against the normal trend of fuel flow going down with gains in altitude. I was actually conducting an experimental flight on solo to adjust my Simbrief values with the efficiency in IF, when this raised my eyebrows. I had to double check and I still see this.
Do you notice how the fuel goes down while my power setting remains the same? The a330 family doesn’t do that, which could mean the a330 is actually burning more fuel than intended, or maybe not. The higher altitudes may be fine, but there is some error for sure with the lower altitudes with fuel burn. Like I said, I don’t know if this carries over to the higher altitudes I’ve only tested a small area to show the issue.
True, but the 77W is exhibiting the correct behavior for fuel burn like most jets in the sim. I can’t say that for the a330. It’s burning more when it should be less. I have looked at @AndrewWu 's guide on fuel burn. Another jet that may behave like the a330 with this altitude-burn issue is the 757. I tested it at max speed, MTOW, at FL310. It reached an n1 of 92% and when I step climbed maintaining power, I found the jet was burning more when it should not. That’s why there was a bunch of orange areas at typical altitudes until the plane reached a very light weight at FL410. I fear the same might be true for the a330.
