CONF iture;
A FRA type error in the Vr speed would explain a tailstrike half down the runway, but not an airplane still on the ground after 12000 feet.
No, I agree it doesn't, so perhaps V speed calculation and entry seem less plausible as one explanation. The other notion (not established fact, yet) that has been expressed, twice now, is the indication of 3 separate strikes on the runway. We might expand on this, given the cautions expressed in the FCOM which I offered on page 1. The airplane is in Direct Law in the rotation phase. I know for a fact that if the rotation of this airplane is mishandled, (ie, PF senses a high rotation rate (cautioned against) and does not strictly adhere to the FCOM procedures and instead checks forward on the sidestick), the airplane will respond very sharply to a reduced up-elevator command. I asked the question about "porpoising" because that it what the airplane may do if control of the rotation maneuver is lost through PIO, [pilot-induced oscillation]. This has happened on this type but not to those with experience on type. The key is a steady pull of 2/3rds back-stick. Check forward and the airplane will respond
very sharply.
Now, this is absolutely in the realm of speculation but it is informed through knowledge and experience and not just guesswork. The cautions in the FCOM are there for a reason.
This may or may not explain the long takeoff run.
Unless thrust setting procedures were badly abused (warnings ignored and
I can't see that happening), I can't see a "low power" issue on this airplane - that's not the way the airplane works.
If the thrust levers are not in either the TOGA or FLX/MCT detents a warnings, ECAM message, "THR LEVERS NOT SET" + chime + Master Caution, occur. If the Flex temperature entered in the MCDU (FMC interface) is too high (ie., higher than the OAT), the A/T - FADEC system will reference and the engines will produce, MCT - Max Continuous which would be at least equal to the maximum Flex thrust available anyway.
A weight entry error here as you describe, (ZFW into the GTOW) will not, I believe (not certain here), reduce the thrust setting dramatically, but that remains an open question for me, obviously, for the moment.
Bird On:
just to clarify for you, at EK the final loadsheet is mostly recieved by ACARS but all T/O performance calculations are calculated by the flight crew using the onboard Laptop computer and then inserted into the MCDU.
Thank you very much - very helpful info. The procedure I am familiar with is different, as described. Both methods work well.