Question for ATR pilots (VOR App.)

[tcasok]

Hi,


There is nothing written in my SOPs and I´m not sure about the technique using AFCS to fly a VOR approach. I would be very appreciated if you could explain the following scenario:

You are flying in HDG mode and you are cleared for a VOR approach. Do you continue in HDG for VOR approach? What is the best procedure and techniques for a VOR approach in ATR 72/500? When do you change the CRS during the VOR approach?


Thanks in advance.

[tcasok]

O.k, 280 (atr pilots or so) and none has flown a VOR approach, the same as me.

[Mach E Avelli]

OK, I will go out on a limb here. Not that I have flown that model, but I doubt there is any difference in technique to any other similar system.
Select course to outbound track. Fly the intercept in HDG, then -optionally -select V/L (or simply track it in HDG if you want to reduce the button pressing - it doesn't matter much on the outbound, just so long as you remain within tolerance).
At procedure turn/base turn, select HDG (if not already in that mode), select both CRS to the inbound. When within approx 45 degrees of the inbound course, re arm V/L. Once the inbound course is captured, set HDG to missed approach, just like you would for an ILS.
If you are being radar vectored, you will remain in HDG until ATC place you on an intercept heading AND clear you for the approach. Then arm V/L. Same as ILS, except you won't be arming the glide slope when established inbound. There is little difference between a VOR approach and a Localiser-only approach. The VOR is less accurate and may not always align you with the runway centreline. One clue to how good the alignment will be is to be found by looking at where the VOR is situated. If it's to one side of the runway, expect to be off centre when you become visual.
How you manage the vertical modes on final descent is a whole other discussion, but I favour VS with the minima armed on the ALTSEL until either captured at circling, or within 300 feet for straight in (runway approach), then reset missed approach altitude. The autopilot is your best friend for circling, so leave it engaged until ready to descend to the runway on base leg. Then disconnect and get rid of the flight directors!
However, for the runway approach, best to disconnect autopilot at or before 300 ft above MDA to prevent it attempting to flare, then reselect ALTSEL to the missed approach altitude (that would be PNF's duty as you will now be hand flying).
Of course your FCOM may have other ideas, and that must prevail.

[Amadis of Gaul]

I think his very predicament is that his FCOM allegedly HAS no other ideas on the subject. Whether that's credible or not is another matter altogether.