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satpak77
31st May 2012, 20:08
RE: ProLine 21 / Collins FMS-3000

NOTE: Still learning the system, nice and slow, one day at a time, know my limits. With that said :

Getting some different opinions, regarding when/whether to use NAV mode or APPR mode when executing an IFR approach.

a few guys at my place advocate

NAV mode: LNAV only Approach, RNAV with MDA, VOR Approach, anything with MDA is NAV mode

APPR mode: anything with a DA

What are the various opinions on this ?

I prefer simple versus hard or "Its an approach, use APPR mode"

galaxy flyer
1st Jun 2012, 04:08
Only used Pro Line 21 on CL 300 and CL 605, but probably the same. Use APPR on all approaches, don't make up "techniques" that are not in the book. You have to be in APPR to get APPR on the PFD, or more accurately, you will get NO APPR just before the FAF indicating that you do not have approach accuracy.

GF

silverknapper
1st Jun 2012, 08:06
GF

I'm not sure that he's making it up. I suspect FSI teach that philosophy.

satpak77
1st Jun 2012, 11:26
No not making it up, know better than that. Possibly heard it at FSI but for sure a few guys at my place claim (maybe they heard it at FSI) use APPR for DA's, and NAV for MDA's.

Take a look at this link, slide 14, and slide 26, the US Navy T-44C training also seems to advocate NAV for non-precision and APPR for precision.

https://docs.google.com/viewer?a=v&q=cache:u8crFgfeTzUJ:home.grandecom.net/~remy1492/R1/T-44CFGP.ppt+VGP+VNAV+T-44&hl=en&pid=bl&srcid=ADGEESjxVPIiJJboz8nCQZj_gWVCyk55JUbQKqhvk-3THJw65dEP-CH4IABYfWR27DPFEpIEL0uf-1xqor586XTBBW8q7NDBdeF_sDsrvLYtt44DnFpTIbQC3POdvOXx7F5Vo8ZWu-R_&sig=AHIEtbRNSkZaXrLVOPppzzqCGPzffdeSXQ

galaxy flyer
1st Jun 2012, 16:16
Always a fav hot topic at recurrent. The reason for using APPR is arm VGP; thus allowing a constant path to the runway and allowing the alt selector to be set to the missed approach altitude. In NAV/VNAV the ALTS must be set to the MDA, the guidance will capture the MDA, but you will lose the path to the runway.

GF

Scroll Lock
1st Jun 2012, 23:23
Well here's how we do it on the H800 xpci....

APPR if doing ILS
APPR if doing VOR or VOR with CDFA ( APPR gives greater accuracy than NAV )
APPR coupled with VNAV if doing FMS VGP approach.

NAV and VS if doing LOC with G/S u/s.

Really the simplest and safest way.

SL

alas8
2nd Jun 2012, 08:57
The main point of APPR mode is to disable PSA capture (or ALTS mode).
If flying ILS app - APPR need to be armed to capture GS. If for example you are cleared to capture LOC only then select LOC as a source and push NAV. When cleared to descent on GS, only then push APPR
If flying RNAV app - APPR mode disables PSA capture (like MDA) and changes course sensitivity from 1 NM full scale to 0.3 NM. It seems to me that FSI doesn't have common SOP regarding activation of APPR mode during RNAV approach. At least I was taught in different ways at two different learning centers. So refer to your company's SOPs.
Certainly if you have circling approach then leave VPATH mode (don't arm APPR) otherwise you will not level-off at MDA and you will have to handle unpleasant distraction at very low altitude.
In our company we arm APPR some 5-10 NM before FAF and fly RNAV approach pretty much like ILS. Providing it is normal straight-in approach with constant descent angle.
On our airplane it is prohibited to use VOR as a NAV source for any approaches, instead you fly RNAV approach (source FMS) and VOR is only monitored by PM. I guess it is common Pro-Line philosophy.
If height is used instead of altitude (UMMM, Russia) then we fly any RNAV approach "manually" - in FMS and VS mode, monitoring VOR or ADF. Feeling is pretty much like on C172.