What would be needed to bring autoland to GA?

Mooney_Driver wrote:

You don’t need a G1000 or GFC700 for that. This is exactly what my test pilots who did the then required certification flight with my airplane did using the Stec 55x, GNS430W and the Aspen PFD

Indeed, it should work on anything as it’s pure “LPV signal being smooth as silk near 10ft above the ground”, however, for getting something like this certified in the dinosaurs world the all Garmin approach for the 1st proof of concept would make it easy (PFD+GNSS+AP), what is not smooth is the vertical profile of the wind and the runway surface

They will be able to show it works consistently under Cat2/3 conditions even if LPV specs are still those of Cat1 as Cat2/3 runways are 50m-60m wide (5 times wingspan and 20 times wheel-span of DA42), 3km long (5 times DA42 distance) and usually with nil wind conditions

In typical GA airports, it will be a nightmare to implement: it’s hard to predict “GPS accuracy check down to wingspan levels” at the time of flare (sort of RAIM check) and they are very short and constrained: even a skilled pilot need to make calculations on takeoff & landing distance every times conditions varies…

Anyone who did his SEP flying on 3km empty runway (e.g. Military or somewhere hot in Mediterranean) can attest how easy to solo after 4h !

Mooney_Driver wrote:

Have you ever tried it in the AN2? I have… it is something which works in theory but mostly ends with the loss of the airframe plus can easily go very wrong. It has really nothing to do with what is debated here, if at all, it is something similar to CAPS. VS is quite massive, we never were allowed to actually land the plane like this but were simply demonstrated how this feels at altitude. Impact would have been pretty remarkable.

I haven’t personally tried it, but it’s explicitly mentioned in the 1959 version of the flight manual. Counterintuitively, the flaps should be retracted.

Peter wrote:

What also helps greatly is the greater landing speed of big jets – a landing in say a 20kt crosswind is much easier to do with a touchdown speed of 120kt than at 80kt.

Crosswind limits for autoland in airliners are way less than 20 kts! Don’t have the books handy but for most part they are less than 10 kts, some less than 5 kts. Which makes perfect sense, as autoland is mostly used in foggy conditions, where wind is mostly zero to 5 kts max.

BTW, by far not all autoland systems are very redundant. The first ones used on the Caravelle 10/11/12 were single channel. They only ever were used by Aeropostale and reportedly by Air Inter when they took over some of those airplanes. The first system was in use on the Trident by the way. Not sure entirely how it was designed.

For GA and part NCO, I would strongly suggest that single channel with appropriate limitations would do the job nicely. Again, Autoland does not necessarily mean CAT II/III even though in airliners that is clearly the idea. However, what autoland almost certainly means is autothrottle or at the very least voice command. I am not sure if the Garmin version also included autobraking btw.

What autoland in any case would do is provide a life line for situations, where you get fogged in. While this is not supposed to happen and while it is rare, it is not unknown that people found themselfs unexpected over a fog situation with little ways out. In such an emergency, autoland would be a viable alternative to CAPS or the mostly ill ending attempts to get down in 0400 VV001

You also need a fairly strong aircraft so it can be “smashed” onto the runway, up to 3-4 times a day, in 20kt crosswind; I don’t think most GA types would last very long

Anecdotal but the autolandings I experienced were all very good landings and not at all smashing like.

Malibuflyer wrote:

How often does this case happen in practice. How many people have died last year in GA airplanes across Europe because the pilot got incapitated and nopbody else in the plane could at put it down into a field?

In the UK in 2013 there was a case where a passenger had to be instructed on how to fly and land a small plane (pilot did not survive it – heart attack well before landing).

Actually, just found this Wikipedia article:

https://en.wikipedia.org/wiki/Talk-down_aircraft_landing

Mooney_Driver wrote:

Another case where something like this might have saved the day was the Helios 737 where the pilots forgot to turn on cabin pressure and both became incapacitated because of hypoxia. The steward (PPL/C172student) who entered the cockpit would have been able to get the plane to land with a feature like this.

If I remember correctly, the aircraft was already almost out of fuel by the time the steward managed to entered the cockpit. As the cockpit door was locked, he had to break in by force which took some time.

Btw: This is a case where the rule of locked cockpit doors killed 121 people. How many have been saved?

Peter wrote:

IIRC the cockpit door unlocks once pressurisation is lost. The cabin crew guy got into the cockpit only as the 737 lost both engines due to fuel starvation. But it’s all out there I am sure. Well, maybe not the bit about the door unlocking…

The door couldn’t have unlocked when pressurisation was lost because then the cabin crew could have got into the cockpit immediately.

It was some time since I read the accident report, but as I recall, there were many load bangs heard on the CVR as the steward forced his way through the cockpit door.