Originally Posted by
SASless
Gipsy.....what airspeed do you use for an ILS Approach?
One single set speed for all approaches or do you use different speeds for different conditions?
How do those approach speeds compare to Vbroc and Vy airspeeds for your aircraft?
We also have to consider all of the possible ways an ILS Approach may be flown...hand flown using raw data right on up to by means of a full capability four axis autopilot system.
That can bring you back to your desire to talk only of SAS/ATT.....is one mode better than the other for a raw data approach or while using an uncoupled FD?
I don't really need to get back on topic. I am just concious this is a good resource and I would love to change the topic title to "SAS, ATT and other AFCS animals"
Anyway, we fly approaches at 100 kts except one particular type where an aircraft limitation holds us to 90kts. The speed is chosen to maximise speed (commercial need), minimises drift from wind and maximises stability without going up into Cat B minima. Nowhere near Vy. Climb out is different though.
Sadly the flying of approaches in a predominantly VFR operation is not easy to practice. There is generally little opportunity to practice when operational flying and every other proficiency check has to have a manually flown ILS in it. So people might fly one ILS automated in 12 months. So building confidence in the various options is difficult. I make everyone fly one either in recurrent training or in test. The whole enforcement of a manually flown 3D approach every rating revalidation is a bit daft. For a 4 axis multiple redundant AFCS there are quite a few failures in a row (or one very sneaky failure that the TRE knows about).