Can a boeing make also the same autoland when only 2 autopilots are working, or must all 3 works for this?

and: would a autoland even work with only one working?Can a boeing make also the same autoland when only 2 autopilots are working, or must all 3 works for this?
The autoland system needs three autopilots to initialize. You can only engage 1 autopilot at a time. The only way all three autopilots can be connected simultaneously is when APP is armed. Each autopilot is then conncted to a separate electrical source. It is possible to autoland using only 2 autopilots, but ONLY after all 3 were first engaged as described above.





Should a failure occur from the time the APP is armed and 200' RA, the autoland status annunciator (ASA) will tell you at a glance your status. You may get Land 2, No Land 3, or No Autoand, depending on the failure. You could lose an autopilot in which case a Land 2 No Land 3 advisory is displayed.





Below 200'RA these are inhibited except for the No Autoland, in which case you need to go around if you're shooting an actual Cat 2 or 3 approach.





BTW, do you know there is an ILS hold point on the taxiway? It is there to protect the ils critical area so that arriving aircraft shooting an autoland approach will not lose the ILS signals during the approach. Aircraft taxiing past that ILS hold point can interfere with the signals received by the arriving flight which could cause a missed approach. It is only ';critical'; when the weather is below 800'RA, or an arriving aircraft requests ATC to keep the area clear to they can practice an autoland.





Finally, airlines always attempt to land at their destination, fuel permitting, unless the weather is below minimums before the final approach fix arrives. Otherwise, you shoot the approach, take a look, and divert as necessary.





If you are Cat 3 qualified, you are expected to fly a Cat 3 approach and land, provided the airPORT has a published and certified Cat 3 approach. It's not a macho thing, it's business. We're trained to do it and the company expects us to perform as we were trained.Can a boeing make also the same autoland when only 2 autopilots are working, or must all 3 works for this?
Autoland needs the specially certified and tested autopilot computer (with autoland), at least one working NAV radio, a CAT III ILS approach, a specialy trained crew, certain type of airplane, and an airport that hasn't closed in 0-0 vis conditions...





The last part is possibly the most critical... most airports won't stay open when the conditions are bad enough to only allow autoland equipped airplanes to land...





While autoland is a great thing, and pilots certified for it practice them pretty often (in VFR conditions) and the passengers dont even know it, they are rarely used to their full potential to land in 0-0 vis... usually a flight will divert before resorting to the autoland as an only option...





In answer to your direct question... if any of the autopilots have failed, a pilot is automatically preparing for the whole autopilot system to fail... (reasoning that whatever caused the first one to fail would maybe cause the other to fail too)... If it was me, there would be NO way that I continue to the destination if the weather is bad enough to even possibly warrant an autoland approach... I would divert... and hand-fly the ILS if necessary at the diversion airport...