Backcountry Pilot • Challenges of gravel bar landings ,uneven surface.

Challenges of gravel bar landings ,uneven surface.

Links to general aviation backcountry flying-oriented videos. It can be yours or stuff you find on the internet. Please no airline/military.
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Challenges of gravel bar landings ,uneven surface.

I find uneven surface and undulations are the hardest to see from the air, logs you can see, or bigger rocks, but uneven surface can be hidden by shadows , color sand, or shape.
Jughead landed before me and told me about this potential jump, I tried looking for it, and tried landing long thinking I already passed it, I never saw it, even after touchdown did not see it, when it threw me back in the air , the moto instinct made me pull on the yoke :) good thing was a jump and not a depression in the surface.

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Re: Challenges of gravel bar landings ,uneven surface.

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Last edited by glacier on Wed Feb 03, 2021 5:46 am, edited 1 time in total.
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Re: Challenges of gravel bar landings ,uneven surface.

glacier wrote:Another very nicely done video. One way to help read bars is to look upstream and see if the channels and currents that formed the bar would have cross cut it at higher water levels. This can also show how various sized gravel and rocks are distributed across the bar. Sometimes it is just hard to tell no matter what, and even dragging the surface with a lightly touching touch and go can be a bad idea if the undulations are big enough and spaced just right to induce oscillations.

Ocean beaches can be hard to read this way too, what might just be patterns of different colored sand on a perfectly flat beach can look exactly the same as rhythmic undulations big enough and spaced just right to put a plane on its back.



That is a great tip.
There is one gravel bar I always land at, we had a period of rain so did not go there like for a month,went back, did a very low pass, where I used to land I saw some new grass growing, nothing else, it looked fine, I just had a hunch , and landed in the rocky section next to the water.
When I inspected it, the new grass section had lots of undulations , and big ones, it would have been ugly.
New grass meant the water was stuck there for a while and the are flooded , and probably created some pools before it dried.

This was impossible to see from the air.
So be aware of new grass!

You can see it on this video on the second landing on the left side.

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Re: Challenges of gravel bar landings ,uneven surface.

One of the best ways to know how smooth or how rough a spot is, is to drag it. When you have a place that you can go around the safest way to make a decision about the condition is to first run your tires down it with the intention of going around. Never ever drag a strip and then decide to land it while you are dragging it.

You would have found that wash out without being so slow as to sink back into it. You also have better over the nose visibility because you are not dragging a spot behind the power curve, most likely you would have saw it before your tires hit it. Just my opinion from thousand of off airport landings.
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Re: Challenges of gravel bar landings ,uneven surface.

Mauleguy wrote:One of the best ways to know how smooth or how rough a spot is, is to drag it. When you have a place that you can go around the safest way to make a decision about the condition is to first run your tires down it with the intention of going around. Never ever drag a strip and then decide to land it while you are dragging it.

You would have found that wash out without being so slow as to sink back into it. You also have better over the nose visibility because you are not dragging a spot behind the power curve, most likely you would have saw it before your tires hit it. Just my opinion from thousand of off airport landings.


What he ^^^ said. There are lots of things that are tough to see easily by just flying by. That's why we drag a landing area prior to landing. And, there's dragging, and then there's dragging. That first drag needs to be VERY light. That'll highlight stuff like the undulations you saw in your video, and you'll just get a "bump" from them, as opposed to a real roller coaster ride, and possibly uglier.

Then, ALWAYS, ALWAYS land where you drug..... [-X Don't drag a spot, then land right next to it. Requires that you get some landmarks you can see when landing.

And, then of course, there are soft spots..... :x

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Re: Challenges of gravel bar landings ,uneven surface.

Speaking of soft spots...

Never assume that a beautiful sandy beach is what it looks like. Especially at the bottom of a glacier. Ice can be buried in the sand, melt, and then you have a not so small cave just below the surface. We were lucky here to have 35's on the plane.

Now where did those keys go?

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Re: Challenges of gravel bar landings ,uneven surface.

And those same uneven surfaces in the winter, not so much on gravel bars but everywhere else, sure make ski flying interesting! The other day I had just touched down and was thinking "wow this snow is really soft", when I touched down AGAIN, not realizing I had balloned up due to an unseen snow drift. Hard bright light too, still didn't see the damn thing.
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