Something else to keep in mind for the B737 flyers...
Above around 180 kt, engine windmilling allows the engine driven hydraulic pumps to supply enough pressure for normal flight control operation while below 180 kt, it starts to feel like manual reversion.
If you get too slow and feel the need to select more flap, say flap 10 at 180 kt you create the situation where the rate of descent has to be increased to maintain speed. The descent path now steepens much more than 3 degrees, and the rate of descent increases significantly (around 2000 fpm). You then require a huge flare as you approach the ground which causes the airspeed to bleed off rapidly, which then causes the manual reversion to come back again which means you can't really flare enough and/or the stick shaker starts to go off and you're now really short of the runway anyway and ... yuck.
Much better to come in above glide slope (one dot as suggested would be good) and keep the speed up around 210 kts. The speed won't increase too much with the engines windmilling (It is interesting to note at this time just how much two engines at idle thrust contribute to the gliding performance). Once you think the momentum will carry you, take flap 1 and then maybe flap 5 and then when you're really sure, take the gear down. But don't let the speed go below around 180-190 kt to avoid the manual reversion!
So from my experience in the sim...
Approaching the flare point at the runway threshold with flap 1 at around 190 kt with a vertical speed around 1000 fpm with enough flight control authority to arrest the rate of descent in a "normal" flare
is way way beter than falling short of the runway with flap 15, an airspeed of 170 kt and decreasing, and a rate of descent of 2000 fpm, whlie losing sufficient hydraulic pressure and having nothing happen when you make one last pull back on the control column just before ground impact, exept maybe causing the stick shaker to go off!
