Synthetic Vision

Jim K

Jim K

Final Approach
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Richard Digits
I'm late to the party, I know.

I use garmin pilot, and it has the ability to display "synthetic vision". I was aware of it, but I never used it because I didn't see the point. I figured if you break out, you have plenty of time to see the runway, and if you don't, you go missed... what good does seeing an electronic representation of the runway do you?

So I had my engine fiasco in February, which turned out about as well as it could have, but in that thread, @NotarPilot asked if I used syn vis to get down. I thought "gee that would've been a good idea, I should play with that".

Ironically, the February "simulator challenge" in IFR Magazine involved landing with zero visibility, including using syn vis. I finally got around to doing it today.... it's like cheating. I get it now.

If you haven't played with it in the simulator, I highly recommend it. The exercise in the magazine involves setting the visibility to 0/0 and flying the approach to landing as though it were a minimum fuel emergency. Once with only the panel gps (no efb), once with all tools available, and once with the efb only..... and the computer monitor turned off. It sounds crazy but it's kind of fun.

Anyway, if you're like me and never thought too much about syn vis, give it a shot. I expect to use it on a regular basis from now on.... if I can just get my airplane back.
 
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I read an article in the Twin Cessna flyer a while back of a 340 in Canada that couldn’t maintain altitude in the mountain west. Think severe icing encounter? They went below ATC’s radar and used synthetic vision to get between mountain peaks and eventually broke out to land.

I’ve toyed with it for possible emergencies and have been impressed. Started pulling it up on the IFD550 while IMC.
 
Flying at night in mountainous terrain, it’s reassuring to see where exactly the terrain is and the velocity vector / projected path’s relation to it. A better presentation for antennas along your path vs an overhead plan view as well.
 
I had synthetic vision on my IFly 740 in my experimental. I think I looked at it once, but never really used it again.

That is, until I made a terrible decision two summers ago to take off from Central Oregon to my home in Central CA. I thought my route would keep me upwind of the smoke. I was wrong.

The farther I went, the lower I got pushed down in order to maintain visibility of the ground. It wasn't long before I'm at 1000 agl in semi-mountainous terrain. And I am not familiar with the area, at all.

I'm following a road so I have some kind of out. But then the road heads into a pass and the tops of the terrain on either side are hidden in the smoke. Yes, I now I was getting nervous and considering my options. Landing on the road below was do-able and it was at the forefront of my mind.

And then I remembered the synth. vision on my IFly. I started it up and it displayed the terrain on the other side of the pass. It was a revelation how important this feature was at that moment. By being able to cross check the synth data with my moving map data, it gave me a reasonable confidence in the course I was taking. It got me thru the pass (still at 1000 agl or so) with some confidence and was instrumental in getting me safely to a nearby airport.

To be clear, I would never intentionally use this to navigate in low vis. But when I needed it because I screwed up, it was a huge benefit.
 
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One thing to consider is whether the syn vision is giving you the view out the window or if it is giving you the view relative to the track. In some cases the AHRS data is coming from a GTX345, GNX375 or GDL51 and I don't think those take into account heading. You could be landing with a crab.
 
Velocity173 said:
Flying at night in mountainous terrain, it’s reassuring to see where exactly the terrain is and the velocity vector / projected path’s relation to it. A better presentation for antennas along your path vs an overhead plan view as well.
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That's what it is for. It's not for landing or takeoff when you can't see the runway. Enhanced vision might work, but that is a heavy iron gadget.
 
Several years ago I got into a situation where I was in a pocket of low vis in the mountains in a basic VFR airplane(story for another time) I was presented with the options of landing in a riverbed or flying into IMC with no instrumentation which would have been a death sentence, Anyway I got out fine without bending the airplane, but very shaken up. Ever since then I've prioritized having a very safe airplane from an avionics perspective for situations like that. That includes synthetic vision, and back-up synthetic vision.

It also has the added benefit of soothing me while in IMC. It's like a nice little window into the clear world.
 
I use foreflight with that same syn vis capability. Operationally, I only brief it anytime I expect to encounter IMC on my flight, at which point I use it as a standby to my vacuum system.

Interesting use case for its use for 0/0 emergency landings. I suppose I would imagine the hardest part of that would be timing the flare. Does syn vis help you with that?

(Maybe I just need to try it)
 
It's great for terrain features. The little runway is meh, but the the actual simulated 'world' is great to have
 
The 0/0 landing idea seems a theoretical benefit of synthetic vision. More likely seems emergency use in engine failure over mountainous terrain or the typical use. I typically use it for heads up alerting of towers when low level, and runway depiction in either unfamiliar or low visibility. I also use it on ils for runway depiction close in when the needle starts getting sensitive.
 
All I'm saying is, I had it and didn't use it because I had never practiced with it. It's definitely not good enough to flare with as it lags a bit. I'm not sure if that's an issue with the sim or if it would perform the same IRL. It would however get you over the runway and low enough to land without tearing things up too bad. In my case where I had no forward visibility it would've helped a lot; I was able to gauge the flare out of the side window once we were low over the runway.

I've never seen true 0/0 HERE. About the densest fog we get is 1/8 mile, which would be plenty to gauge your flare if you can find the runway. The simulator produced about 100' visibility. I never saw the approach lights, but found the runway each time. The time I tried with the monitor off (judging the flare on the synvis) was the only time I "crashed". Again, this is all a bit silly....if you find yourself in a situation contemplating a 0/0 approach with no fuel for a missed, you've already screwed up multiple times. The point is to practice with the tool to see what it's capable of and have it top of mind when you need it.
 
Jim K said:
I've never seen true 0/0 HERE. About the densest fog we get is 1/8 mile, which would be plenty to gauge your flare if you can find the runway. The simulator produced about 100' visibility. I never saw the approach lights, but found the runway each time. The time I tried with the monitor off (judging the flare on the synvis) was the only time I "crashed". Again, this is all a bit silly....if you find yourself in a situation contemplating a 0/0 approach with no fuel for a missed, you've already screwed up multiple times. The point is to practice with the tool to see what it's capable of and have it top of mind when you need it.
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The track-aligned view vs heading-aligned view I mentioned earlier extends beyond trying to land 0/0. When you break out, the road you've been following on syn-vis could be out your side window if there's a stiff crosswind.
 
I have SV installed in my G1000 NXi PFD and love it. And since I also use FF for EFB, it's there too. It's just additional information that adds to the safety of a flight...
 
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FPK1 said:
I have SV installed in my G1000 NXi PFD and love it. And since I also use FF for EFB, it's there too. It's just additional information that adds to the safety of a flight...
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Absolutely! So long as you don't consider it enhanced vision for descent below DA/MDA and for landing when you can't see the runway.
 
FPK1 said:
I have SV installed in my G1000 NXi PFD and love it. And since I also use FF for EFB, it's there too. It's just additional information that adds to the safety of a flight...
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I use it on my GI275s less for the see the runway and more for the green circle (silly Garmin feature placement). But being able to see the hills was nice the couple of times I played with it “in anger”. I always forget to look at it on final, so on the 275s, I’ve never seen the simulated runway :).
 
It’s an awesome tool as long as you have an ADHRS feed. It’s worthless without.
 
aterpster said:
Absolutely! So long as you don't consider it enhanced vision for descent below DA/MDA and for landing when you can't see the runway.
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One of the podcasters did that with a view limiting device and an instructor. I heard of an engine failure case where the pilot used SV to penetrate undercast, and it worked very well. I would never use SV to violate minima, but as opposed to a forced descent through a layer into unknown terrain, you bet I would.
 
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Without ADHRS is doesn't provide any perspective of bank or attitude.
 
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