Recently did a flight with the inibuilds a330 RR with the built in simbrief airframe. Simbrief takeoff calculator calculated 127/127/138 for v1/r/2 (Image bellow). However on the efb it calculated 155/160/161. What is the reason for this big discrepancy? Can this be improved on? Thanks
Hi, are you sure you used a TOW of 163,000 kg in the EFB? The EFB speeds (155/160/161) are quite high for that weight.
SimBrief’s numbers look correct, based on the data we have.
But it should be noted that with takeoff performance, there is no such thing as a single “correct” number. Rather, multiple different numbers can be valid, depending on what the tool is optimizing for. The runway is long enough for the higher speeds that the EFB has given you, so even if they are unnecessarily high, they are still safe to use. But SimBrief’s speeds seem more realistic in this case.
Best regards,
I used the sync button on the takeoff calculation page after loading the weights with simbrief. Are the a330 takeoff speeds around that low irl? For example in a330 driver’s a330 streams the v speed he uses seems quite high as well.
Takeoff speeds depend a lot on the takeoff weight. An empty aircraft will have much lower speeds than a full aircraft.
In your flight plan you posted, you had a takeoff weight of 163,000 kg. That is quite a light load for an A330, in this case it’s likely because you are flying a short flight that doesn’t require much fuel.
At 163,000 kg, these slow speeds are normal and realistic for an A330-300. It’s possible that A330 Driver’s speeds were higher because he was flying a longer flight or had loaded more payload/fuel. It’s also possible that he was simply using a different tool that optimizes for different parameters (climb performance at the expense of increased takeoff roll, but I can’t say for sure).
Best regards,