Big Boeing/Airbus Autopilot Performance

[Badmachine]

During flight under RNP conditions or approach operations under ILS, how responsive are big Boeing/Airbus autopilots when adjusting to varying winds that might affect waypoint interception or create lateral deviations during approach operations? Do adjustments happen in larger or smaller increments?

Thanks.

:ok:

[welliewanger]

ILS isn't RNP. They're two different regimes.
Nor does ILS have waypoints.

RNP specifies a level of accuracy. The aircraft doesn't go into "RNP mode" it is just certified to that level of accuracy or not. So while flying an RNP route it behaves just the same as any other time.

I think you're asking whether, during times when the aircraft needs to stay on track a very accurate track, does it aggressively regain track? Yes, it does. Sometimes too aggresively and it starts oscilations.

[fredgrav]

Hi badmachine,
autopilot performances on approach have nothing to do with RNP certification.

how responsive are big Boeing/Airbus autopilots when adjusting to varying winds that might affect waypoint interception or create lateral deviations during approach operations?

The more complex AFDS Systems usually damp oscillations while operating under modes that require small attitude/bank variations (eg. APP mode, AUTOLAND etc.) Corrections made by AFDS are also relatively small by flying LNAV and VNAV paths (eg. WPTs sequencing, vertical constraints matching etc.).
Briefly, RNP has more to do with IRS's (Inertial Reference Systems) Accuracy and RNAV capability.

Cheers,
fredgrav