Originally Posted by
PilotLZ
Performing an RNAV GNSS approach with no FDs or in TRACK-FPA is just as wrong as...
This is or at least could be airplane dependent.
During my IR training, the aircraft had a garmin that indicated a lateral deviation and a precise time to perform the turns. Flying RNAV raw data was completely feasible and reasonable.
On the airbus without any precise indication of lateral deviation, yes, impossible, I agree...
If the manufacturer gives less information, then manual flying will be harder.
Try to fly a DME arc with an old DME that gives DME speed : if you know how to use it, you can make a DME arc that's precise to +/- 0.1nm, regardless of wind conditions and other difficulties.
If you try to do the same with a newer equipment (G1000 for example) which does not give DME speed, you lose a valuable information and precision will drop, and mental workload will have to increase in order to compensate.
Now try to perform a DME arc without a DME indicator. It would be forbidden, for the same reason why RNAV without FD is forbidden on the airbus...