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Old 21st Feb 2015, 05:00
  #21 (permalink)  
 
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What has to be understood is that only one AP is actually landing the aircraft, in all aircraft I have experience with. The second and or third are passive and only monitoring. The current standard is triple redundancy, one dominant two comparing ILS and aircraft function.
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Old 21st Feb 2015, 05:11
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Triple redundancy is not really the standard, considering that the most common types only use two (737, A320, both CAT IIIb approved).

On somewhat older 737s you could feel in the controls the second autopilot engaging after the self test around 1500ft AGL was passed. I don't think it is really passive. Even more interesting is the single channel autopilot hardover in the simulator compared between one autopilot engaged and two autopilot engaged.
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Old 21st Feb 2015, 13:28
  #23 (permalink)  
 
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Lightbulb Keyword here is "Emergency"

@ barronflyer: There are countless wonderful responses to your question, yet may are off-topic by introducing criteria not within you simple question.
Your question was:

"...if during an emergency, an AL could be Carried out without operators approval e.g in poor weather conditions, as long as it subscribes to the above criteria?..."

A few got it. (Those who did get it, responded with far fewer words. You pose an important question, complicated for some, but with a simple answer... The key word in your question is 'emergency,' not 'practice' or 'certificated.' As you should know, in a genuine emergency you should fly first, navigate and when able, certainly declare your emergency. (Offering the nature of the emergency is a damn good idea and this is not the time to be cool and understated: give as much information as you reasonably can!)
Even if unable to transmit a Mayday, if you believe that your airplane is in serious danger, you may - and should - do anything reasonably to return it to earth with a safe landing. You Do Not Need ANY permission(s), from ATC, company operations procedure, CAA certificates or any of that balderdash to safely land your aircraft. Communicating with ATC and other aircraft is a very good idea, when possible, but it is NOT required.
In the example that you cited, if the aircraft and airport have Auto Landing capability, and you know how to use it, IMO, this is a no permission required situation: Use what you have and fuss about the details after you are safely on the ground.
Is ditching a better/safer choice? Some may legitimately differ here, but IMO, if you have some Auto Landing capacity, I think it is a better choice than ditching. In the instant, Only You can make that decision - and thank God pilots are rarely faced with such choices.
So what is the best, safest, functional response to your question? Use Every skill and facility that you, the aircraft and the runway has available and hope (pray) for the best. In the most simple terms, do you need 'company approval' to execute an unapproved Auto Landing procedure - in an emergency? Not only no, but Hell No!
If you are a pilot, you should already understand this very simple answer. If not a pilot, perhaps a curious civilian, now you know. Basic air laws have many different ways to express the concept, but in a genuine or perceived emergency you, as the pilot in command, may do virtually anything necessary to safely return your airplane to earth. The only serious qualification that I'd add might be, '...without seriously endangering another aircraft...' In even more simple terms, if your aircraft is in serious danger, you own the airspace. In after the-the-fact investigations nearly the only criteria examined is whether your action was reasonable.
Flight Safety 'Rules' are extremely important guidelines. If you violate one or more in the interest of preserving life, be prepared to justify your action(s) by describing the circumstances of the moment. If you do so, your event is over. And if you do not properly explain your extreme action(s), be prepared to walk, rather than fly.
Yet once more back to the basic of Auto Landing without the certificate: of course you may. If you are successful, you'll be the hero of they day. And if you screw it up, you'll be crucified.
As you should also know, ,there are very few absolute rules when flying. (The only perfect rule that I know of is that if it goes up, it will come down. In all other cases, as dictated by government and company, you are expected to break them if the safety of your aircraft is at stake. I hope that is as clear as mud. The regulatory Gods will get me for this, but if you need the use the airspace or facilities in unconventional ways to assure a safe landing, please do so. How many redundant ways can I say it?

Last edited by No Fly Zone; 21st Feb 2015 at 13:39. Reason: Add partial quote from original question
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Old 21st Feb 2015, 15:22
  #24 (permalink)  
 
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History

Interesting to read about 2 relatively recent cases of use of autoland during fog in Australia.
More than 20 years ago, during interesting conversations with Australian pilots in our company, exactly this kind of "legality and wisdom" matters were the subject.
The Ozzies then already described a case of a crew being caught by fog at Sydney - and they were a crew not (yet) qualified for Low Visibility autoland. So, they considered themselves to be legally not allowed to land, only alternative was to ditch, perhaps in Syney harbour, were the fog did not reach. Some smartass suggested over the radio "how legal do you think that ditching would be?" The crew then decided after all to go ahead with the autoland.
Have never been sure whether it was a 100% real story, or more of a saga to teach airmanship - well, here is documented proof that it happened more than once in years since back then.
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Old 21st Feb 2015, 16:49
  #25 (permalink)  
 
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I'd rather be convicted alive than legally dead. I suspect the pax would be pleased to be innocently alive as well. Isn't the ability to make a critical decision, when you are between a rock and a hard place, what being a good captain/crew is all about? Heavenly powers forbid that in todays SOP monkey world that little not often used facet of captaincy should be forgotten, even ditched.
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