My questions -
1. What flap setting do you use @ the the FAF? (Presicion vs. Non?)
2. Do you teach to add flaps when descending from MDA or going visual at DH?
For your first question, I like to teach and fly "flaps approach" for the final approach segment (one notch in your case). To me, it seems to stabilize things up just a bit and assists with the descent.
Now, for me I also like to teach and prefer to fly a planned descent profile on NPA's rather than "dive and drive" like so many people like to teach and fly. That is to say, if I have 800' to lose from the FAF to MDA and FAF to MAP is 4 miles, I'll just do the math and figure out what my descent rate needs to be. For 90 knots, that would be roughly 300fpm.
(800'/4miles = 200ft/mile * 1.5 miles/min = 300fpm).
Unless there's a step down fix I need to hit, I'll step that up to 500fpm so I can be at MDA a short time prior to the MAP to give me time to look around. This is especially so if I'm circling or it's dark out. I don't really enjoy plummeting towards the Earth at 1000fpm in the clouds, in the dark unless my ground speed and the descent angle requires it...in which case, I've already briefed it.
Now, for your second question. As for final flaps, I'd like to see you turned final (if circling) and/or landing assured before adding more flaps in something light like a 172 or Archer. This way you know that the addition of drag isn't going to make you come up short if/when the engine quits.
I think DH might be a little late to be adding flaps if you're doing 120 knots, but doing 90 knots, you've still got 200 feet to go in the descent and that means ~24 seconds from DH to touchdown so I don't think there's a real problem unless you end up ballooning back into the soup. BTDT
Those planes will land just fine with 10 degrees of flaps, so you may want to consider adding some landing distance (And make it ridiculous too! Say for a flaps 10 landing you add 75% on to your landing distance numbers. It shouldn't be even close to that, so you should be fine.) and just landing with the flaps left at the approach setting.
-mini