Thanks, RichardC10, great analysis.
To be resolved for me remains:
- flight was well above F300 at MEKAR, otherwise no radar contact from Butterworth was possible. It should have made good GS 460 kts from IGARI to MEKAR, otherwise times do not work.
- GS of 311 to 340 kts, needs a lower level to stay above minimum clean ; or non-clean flying; or circling; too low level would reduce range significantly (people with 777 flight manual will tell)
- the curved track cannot be flown with autopilot in HDG mode as magnetic variation is not consistent (maybe with any lateral mode off?)