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Phlyan Pan

Well Known Member
I'm curious, has anyone ever tried to make an approach all the way to touchdown on synthetic vision alone? Is it possible?

I'm picturing putting on the old foggles and having a safety pilot/instructor on board and trying to set down using only a synthetic vision system. Anyone ever tried it?
 
Sounds much like a practice 0/0 approach... Often started as a practice 0/0 takeoff. (not by yourself, as you said...and I'd personally only do stuff like that with a CFI-I that has done it before)

With a competent right seater, why not? Good to know how it would end up in an emergency situation where it was the only option...not that you should ever end up in that situation...but just like all the other what-if training we do but hope never to use. (As long as you don't consider it an option in your advance decision making or for a non-emergency, if it works out well...like some VFR-rated folks do with an A/P and IMC.)

Would be interested in your result and equipment used.
 
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Are you suggesting a zero-zero approach?

Are you asking about a zero-zero approach, or an approach to published minimums? These are two very different things. The former I would only do if I had fumes in the tank and no other out. That would be the result of many failures along the way, poor planning being one of them. The latter is no different than an approach to minimums with steam gauges.

I think you're asking if the syn-vis picture is accurate enough to land in zero-zero conditions. The published accuracy of WAAS is typically on the order of 1.5 meters horizontal and 2+ meters vertically. Assuming you have the field altimeter setting in then you'd be accurate to that, which is only required to be +/-50 IIRC. Are you landing on a narrow runway, and 1.5 meters to the side means a tire off the edge of the pavement? Are you landing on a runway so wide you could probably put it down perpendicular to the runway?

I guess I would take a look at the numerous syn-vis videos available on YouTube and see if you think the sight picture presented on the screen is close enough to the sight picture out the window. In nearly every one I have seen I can discern offsets laterally that would be alarming to me if I was trying to put the plane down without looking...
 
The short answer is that you better be ready for a heck of a bounce! ;)

I have flown a lot of approaches with various Synthetic Vision systems under VFR conditions, monitoring both the SV and the real world, and the accuracy is nowhere near what you would need to accurately flare without looking outside. "Krwalsh" (above) talks about the tolerances, and he's right on - you will either flare a couple feet high or arrive with a bone-jarring bounce. Is it better than crashing at a random spot? I would think yes - but the truth is, you'll probably have at least a few feet of visibility in even an emergency situation to look outside. At least, I hope so....

Paul
 
Ironflight said:
I have flown a lot of approaches with various Synthetic Vision systems under VFR conditions, monitoring both the SV and the real world, and the accuracy is nowhere near what you would need to accurately flare without looking outside.
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That's basically what I was looking for. It was just one of those curiosity things. I'm still a couple of years from even starting a build and who knows how long from starting a panel and of course I too don't plan on ever finding myself in that situation but I was just curious if it was possible.
 
On my GRT, Some SV approaches are dead on. Some show the runway over 1000' off where the TDZ is no where close to the runway.
 
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