MU2 v2 Questions and Notes

[Eli2204]

Hello there! Me and my friend have recently been taking the MU2 all around the country, learning the airplane, and figuring out its quirks. We did, however, see a couple things that raise concerns.

1. Is the MU2 able to execute RNAV- LPV approaches with vertical guidance? We can never seem to get an active glidepath when shooting an LPV approach for the autopilot to take us down to miniums, we have to perform a stepdown approach which is obivously not ideal.

2. The planes autopilot occilates a lot, up and down, on short final, when shooting an ILS approach with the auto pilot on, taking it down to minimums. This can be SORT OF combatted with a higher approach speed, but sometimes its just not feasible to keep the speed up. 

 

Thanks,

Elijah

Edited November 10, 2022 by Eli2204

[tkyler]

On 11/10/2022 at 1:48 PM, Eli2204 said:

Is the MU2 able to execute RNAV- LPV approaches with vertical guidance?

Hi Elijah,

No.  Those are GPS procedures and the SPZ autopilot does not take GPS generated signals.  ILS is the only approach vertical guidance option for  the older AP.

Regarding the oscillation,  what approach speeds are you seeing this at .  I can try to simulate and look at the AP constants. I've had descent stability at 110-120 kias and TBH, haven't testes the AP constants a lot below those speeds.  

Also...is this XP11 or 12? 

TomK

 

[dbw11]

Will the aircraft follow the approach LNAV and the vertical component to be controlled manually by the pilot?

[tkyler]

Laterally, the AP will track GPS tracks,  ILSs and VORs 'paths'.   Vertical modes are always initiated / controlled by the pilot manually as you state.  For lateral AP tracking purposes, a GPS track doesn't know if its its part of an approach/LNAV, an enroute segment, whatever...those are labels we put on the path....not the AP...its just a magenta line to "stay on" as far as the AP is concerned.  So if you can enter some LNAV approach on a GPS unit and get it to display as a 'magenta' GPS track, then the AP will follow it laterally in GPSS mode. Vertical still needs to be manual though.  In XP11, the GPS tracks do not display the approaches selected from the GPS units....they had to be entered 'waypoint by waypoint'.  I'm unsure if that's changed in XP12, seems I heard it was but haven't tested that functionality yet. 

-TomK

Edited November 27, 2022 by tkyler