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DA42 experimental autoland

US AOPA article

This has already been available for homebuilts fitted with an autopilot. One is a “box” but I can’t find the link to it, and this is an Ipad app which links to the autopilot somehow.

Obviously any solution needs to know the airdata (wind aloft, heading, etc).

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

Obviously any solution needs to know the airdata (wind aloft, heading, etc).

GPS altitude and indicated airspeed would be the minimum requirement I think. The autopilot does not need to know magnetic heading and wind aloft in order to track a GPS course and approach path. But for a proper flare, either IAS or AoA will be required as input.
For an aeroplane like the DA42 with FADEC engines and mostly electrical systems (gear, flaps) and a good autopilot, this autoland feature seems realistic. But for anything else, the servos required to operate all those controls will probably exceed the value of the aircraft.

EDDS - Stuttgart

Autoland is normally done on radalt I think – there would be too many issues with GPS alt for certification I would think

Now retired from forums best wishes

Yes, the DA42 mentioned needs to have a RADALT. Jets with Cat3 switch from baro to the RADALT at something like 150ft.

Administrator
Shoreham EGKA, United Kingdom

The X-plane person has created one together with Vertical Power, but I think the whole thing ended when Vertical Power was purchased by some other company. It did work though, installed and tested in an RV. There is also this “manual” version that can be used in all planes.

Xavion is always imagining the worst that could happen, so you don’t have to.

If you have an engine out, Xavion will plot an easy-to-fly course to a nearby runway.

Xavion knows about your plane’s glide characteristics and the nearby terrain, so it guides you to the safest nearby runway—not just the closest.

It’s almost like I have to get an iPad just to try it out.

The elephant is the circulation
ENVA ENOP ENMO, Norway

Without wind info, this can work only with very generous margins.

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

Without wind info, this can work only with very generous margins.

Why? I think we already talked about windsocks earlier and I am one of those people who almost never look at it. During approach, you watch your airspeed and establish a drift angle that keeps you on the extended centerline. For this emergency autoland feature, knowing the general wind direction would be useful of course so that it can chose an into-wind runway.

EDDS - Stuttgart

Maybe we have wires crossed but basically the glide radius varies with the wind. You can glide further downwind. The difference could be huge, with piston aircraft.

The direction of the landing itself is much less relevant IF you arrive at the airport centre at say 1500-2000ft.

I would think that any system which takes over and glides you to an airport would need to have a margin of at least 30%. That would mean discarding at least half the airfields which might statistically be within the glide radius.

Administrator
Shoreham EGKA, United Kingdom

Interesting proposition, I would think there would be more chance of ending up in a smoking hole with an auto land than an automatically deployed ballistic parachute.

Ps – I don’t know exactly what algorithms some of the GPS systems use to produce wind information but I frequently see some odd read outs on the Garmin 1000 that are obviously wrong, must be some kind of averaging calculation?

Pps – accurate speed control is vital to maintain the most efficient glide, I test many candidates where poor speed control during practice forced landing results in massive differences in glide performance and chance of success

Now retired from forums best wishes

Peter wrote:

Maybe we have wires crossed but basically the glide radius varies with the wind.

Yes of course. But I was thinking of this Da42 only which does not need to be able to glide anywhere.

EDDS - Stuttgart
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