Autoland

[PaulF]

probably one for TimC...


Very foggy at Copenhagen today so we were told to switch off all electronic devices as we would be doing an automatic landing.


Is this normal, or peculiar to the airport here? I thought all landings at Heathrow for example were automatic 

[hatler]

I thought the thread title was going to take us into a dystopian car-based future.

[hatler]

Though of course, some would say we are already there.

[trekker12]

I'm sure TimC will be along shortly but my understanding is that all modern airliners have an autoland feature and they are connected to the ILS (Instrument Landing System) at the airport - again all modern large airports have ILS. Autoland is not a very new system. The British were mucking around with it shortly after the war and airliners have had systems since the 1970s.

Normally, when visibility is sufficient the pilot will manually fly the landing with guidance from the ILS to tell him/her the aircraft is on track at the correct glide ratio and alignment with the runway. This has higher limits on crosswinds and windshear as the pilot can react to what they are feeling. Also the aircraft fly closer together so you can have more landings in a shorter space of time.

Instrument landings take place when it is overcast but visibility to the runway is acceptable. The ILS will get you through the overcast and the pilot takes over closer to the runway than in full visual conditions. I believe this is up to about 600 meters visibility but I don't know the exact numbers.

Finally there is the autoland which is when the pilot doesn't control the aircraft at all. This is when visibility is below acceptable (<600m if I'm right above) for a normal ILS landing. I don't think it happens everywhere but most modern airports have the capability. There are limits on crosswinds as well.

[caerau]

I thought pilots were required to occasionally at least do a manual landing otherwise they never get any practice at it.  Sounds sensible practice to me.


I once flew to Guersney and then had to fly all the way back again (to Southampton) because it was foggy and they couldn't land.  But then this was in the 90s with a twin propellor type plane and by any stretch of the imagination Guernsey doesn't have a large airport.

[trekker12]

I believe they have to maintain 'currency' of both types of landing so will do autolands in good conditions if needed to maintain the practice and also to land manually regularly as well. I think it's better to do a manual landing for the airport as they can get more airliners down per hour than if they are all on autoland. My interest in aviation is more of the plane spotting and flight sim variety so not needing a license for either of those I don't know the exact rules.

I would imagine it takes some confidence to sit 'hands off' and wait for a computer to land a heavy airliner full of people than rely on your training and instincts. And some of us are nervous of Google self drive!

[caerau]

And some of us are nervous of Google self drive!

Well quite

[Cudzoziemiec]

I thought the thread title was going to take us into a dystopian car-based future.

Not just me then.

[caerau]

I thought the thread title was going to take us into a dystopian car-based future.

Not just me then.

And me

[Kim]

And some of us are nervous of Google self drive!

Well quite

I've said it before and I'll say it again: If it goes wrong it kills you just as dead, but flying a plane's much less complicated for a computer than driving a car.  It doesn't have to worry about identifying, anticipating and avoiding other traffic, which is the really difficult stuff, because there are proven systems in place to ensure it won't be there (and even if there weren't, it would be much less dense anyway).  The actual computer-controlling of the aircraft is well established technology, albeit usually with a human pilot making the high-level decisions.

By analogy, cars^[1] have been successfully driving themselves on *empty* roads since the 1990s.

Not to trivialise the engineering that goes into either, particularly the redundant fail-safe design of aircraft systems (which is the sort of thing that cars are going to need if we do away with human drivers entirely).  But driving a car in traffic is far more difficult.  You can't just stay hundreds of metres away from all other moving objects for safety.



_{[1] Well, in the early days vans.  Because Moore's Law.}

[caerau]

Oh go on then, I'll give you that one 

[citoyen]

I was going to say something about planes not having to share the airspace with boy racers, but I see Kim has already made the point in more detail.

It doesn't have to worry about identifying, anticipating and avoiding other traffic

On topic: there was a crash involving an Uber self-driving car in Arizona over the weekend - one report I heard on the radio suggested it was caused by another (human) driver not giving way at a left turn.

[jsabine]

And it's resulted in Uber pulling all of the trial vehicles ...

[citoyen]

And it's resulted in Uber pulling all of the trial vehicles ...

And I bet the Uber car wasn't wearing a helmet.

[Kim]

And it's resulted in Uber pulling all of the trial vehicles ...

Finally determining the level of bad publicity they're willing to accept.

[caerau]

And it's resulted in Uber pulling all of the trial vehicles ...

Finally determining the level of bad publicity they're willing to accept.

*wipes the coffee he was drinking from the screen* 

[PaulF]

I'm sure TimC will be along shortly but my understanding is that all modern airliners have an autoland feature and they are connected to the ILS (Instrument Landing System) at the airport - again all modern large airports have ILS. Autoland is not a very new system. The British were mucking around with it shortly after the war and airliners have had systems since the 1970s.

Normally, when visibility is sufficient the pilot will manually fly the landing with guidance from the ILS to tell him/her the aircraft is on track at the correct glide ratio and alignment with the runway. This has higher limits on crosswinds and windshear as the pilot can react to what they are feeling. Also the aircraft fly closer together so you can have more landings in a shorter space of time.

Instrument landings take place when it is overcast but visibility to the runway is acceptable. The ILS will get you through the overcast and the pilot takes over closer to the runway than in full visual conditions. I believe this is up to about 600 meters visibility but I don't know the exact numbers.

Finally there is the autoland which is when the pilot doesn't control the aircraft at all. This is when visibility is below acceptable (<600m if I'm right above) for a normal ILS landing. I don't think it happens everywhere but most modern airports have the capability. There are limits on crosswinds as well.

Thanks. A little subsequent Googling showed my initial assumption that "all landings at Heathrow use auto land" was wrong, hence my confusion 

[renard]

Trecker12 has done a very good write up.

Most landings are manual.

With the flight into Copenhagen it would appear that an auto land was performed.

We have a checklist to complete before carrying out an auto land and that includes switching off portable electronic devices.

There are a number of categories of Autoland.

The most common is Cat IIIa.  Minimum visibility is 200m.  No limit on cloud base but at 50' we have to be able to the runway lights, or abort the landing.

The autopilot flies the whole approach with the crew monitoring it performance.  There are quite a few scenarios where the landing may have to be aborted, either due to aircraft malfunctions or ground based malfunctions.  We practice for these every six months in a simulator.

[citoyen]

I've often wondered... is the Die Hard scenario feasible, where a hacker fools the plane's systems into thinking it is at a higher altitude than it is?

[ian]

Even if it isn't, there's nothing in a Die Hard movie that I won't believe. It's the most truthiest series of movies there is. Apart from the last one which is full of lies.

Despite flying a zillion times, this has never happened to me. I expect my pilots to do some work, it can't all be G&Ts and cabin attendants (is that the title du jour, they're probably inflight cabin executives or somesuch these days).

On my last flight as we were about to touch down, the runway streaming below when garoom go the engines and and back up we go. Apparently the plane ahead of us hadn't sufficiently cleared the runway. Going by his withering tone, our pilot didn't sound especially impressed by this. What's that Skippy? Trouble in the pilots' lounge?

[Kim]

I've often wondered... is the Die Hard scenario feasible, where a hacker fools the plane's systems into thinking it is at a higher altitude than it is?

Assuming the right lack-of-visibility conditions, you'd have to hack the ILS (as per Die Hard, though I expect it would mean more fiddling with aerials than pressing buttons), the GPS (doable with enough tech), the barometric altimeter and the reference they're being compared to.  I'd guess that means documents on the plane, plus whoever the pilot's talking to on the radio.  Plus anything else I haven't thought of.

I don't see all that happening without advance physical access to the plane.  At which point it would be easier to install a bomb or arrange a catastrophic systems failure or something.


(While we're on the subject, a trail of igniting fuel progresses at well below the stall speed of a 747.  This is far more disappointing.)

[ian]

Yes, but it was snowing. And Christmas.

[caerau]

One of these days I'm going to have to actually watch Die Hard II.  It's a weird twist of fate that I've never managed it, though I've seen bits.

[ian]

It's the best one!

[Asterix, the former Gaul.]

probably one for TimC...


Very foggy at Copenhagen today so we were told to switch off all electronic devices as we would be doing an automatic landing.


Is this normal, or peculiar to the airport here? I thought all landings at Heathrow for example were automatic

I'm pretty sure I'd a flight back from Greece that did an automatic landing.   The pilot was an Australian or New Zealander and told us the plane had landed itself just after it did it.  That must have been c. 2000 ad or earlier.  He also made some crack about landing in the water but that was before we took off

I also remember my first airline flight.  I wasn't at all worried by the rather loud the creaking noises the plane made as I thought it was normal but no other aircraft has done it since my flight on that Tupolev.