Cat 3A Autoland

[swashplate]

Firstly....

Do I have this right?

Cat 3A autoland: 50ft decision height, 200 metres Runway vis range


Assuming that's right, I'm wondering what happens on a cat 3A approach at the DH?

If you are visual at 50ft, do you leave the autopilots in for the landing and rollout?

Or do you take over, and hand fly the rest of the way from 50ft to touchdown and roll-out?


.....just interested (occasional B737 SLF)..... :D

[ETOPS]

swashplate

When autolands were first introduced, the autopilots were not as reliable as modern equipment. Thus the limits had to be set to cover an autopilot disconnect at DH. This has happened to me on a number of occasions - the co-pilot calling "Land manual" if the automatics failed after the DH had been passed. It wasn't easy to see exactly where you were at that point in the flare but you could usually get a reasonable landing. If you decided to go around the flying manual helpfully stated " the aircraft may touchdown briefly during this manoeuver" or in other words you bounced back into the air!

Now that we have triple digital autopilots with high reliability and redundancy we can regularly operate in 75m/no DH knowing that the chance of a complete failure is remote.......

[swashplate]

So I take it that my 737 chauffers would leave the A/P in after 50ft then?

[Denti]

Yep, they would. But the autopilot will disconnect 2 seconds (or so) after touchdown. The B737 doesn't have a rollout capability. The critical callout is "no flare" ;)