Hello cvgpilot..G334 is a RNAV route linking WMKK and WBGG and other destinations in Sarawak. If you were to refer to the Malaysian AIP under
Section ENR 3.1-9, it is highlighted that only FL250/270 are allocated.The reason is SIN ATC in cooperation with KUL ATC has agreed to a NO-PDC LEVEL of 250/270(eastbound) and 260/280(westbound) for this route. No closing speed on MNT.
No PDC? No pre departure coordination.This agreement between both countries is to ease ATC coordination. Likewise a No PDC arrangement is also available for M758/M761 after VPK which is
250/270/290 from KUL. Anything higher is subject to real time coordination between both ACC. Now coming back to your predicament. When an aircraft FPLs on G334, The Ctlers mind is somewhat 'locked' to say (its definitely a non-rvsm acft unless they refer to your FPL) i.e why they asked whether u are rvsm compliant. ATC wasnt confused. It was your ground handler who goofed up things.He should have checked details at the KUL AIS. SIN ATC will never accept anything higher than F270 via UKASA due to their numerous crossing traffic via VMR. It is sincerely hoped that a thourough briefing be given by your ground-handler before signing off a flight.
