Tying down to sand and rocks. Nose or tail into the wind?

[Paul Amstutz]

Having sat in the pilots seat though a night of high gusty winds while marginally tied down to sand and rock in the Utah desert (to add 170 pounds dead weight to the plane, and besides my tent blew over), twice this summer gave me lots of time to think about how to tie the plane down without worry. For sand I now carry a couple of heavy nylon fabric dry bags that I can fill with sand, tie a rope around, then dig a hole and bury them. (use them to carry water to begin with) For slick rock below 2" of sand that I can't dig a hole into, I find the biggest rock I can carry and tie the rope to that, then pile a bunch more rocks on top of it.

Where there is good dirt/clay I use Fly Ties-three spikes at angles-and them still pile rocks on top if available.

An experienced back country flier suggested in sand/dirt digging a hole to drop each main wheel into to lower the angle of attack. (plane is M7, conventional gear).

Does anyone have a comment on advisability of:

1 negative flaps with nose into wind-assuming that the wind is blowing in one general direction when you tie down
2 tie down with tail into wind-same assumption
3 somehow secure the elevator full down with nose into wind so that if somehow a big gust came along it might lift the tail some to lower the angle of attack, I carrying a telescopic hiking poke I could wedge between seat and yoke with some padding, I tie the yokes together with nylon cord to keep the ailerons from moving, have also thought about making a wooden clamp to do the same, could make a wood brace to hole the yoke in also
4 are there any (inflatable?) leading edge/wing top surface devices that are compact that could be helpful in killing lift?

thanks in advance for any ideas, paul

[crbnunit]

You have a different flap system than I do but my flaps get thrashed if I don't use gust locks facing away from the wind. Can't be good for the rudder or elevators either. Most of the guys up here park facing the wind to prevent control/rigging damage and we get some GNARLY winds. The last storm here had peak gusts at over 100mph!

There are quite a few use wing covers with built in spoilers to kill lift. Mine have them but I took the semi ridged spoiler material (pipe insulation) out because it makes them a pain to get on and off by myself. It is a good idea though. I have heard of guys padding 2"-3" birch trees and tying them to the wings to kill lift though I have never seen it.

I've used the rock/log buried by other rocks/logs. The soil up here isn't great for anchors of the less than permanent kind. I've used trees, bushes, rocks, logs, sand hogs... Never thought about digging holes for the mains. Sounds like a pain though. Getting back out might not be fun!

[aero101]

When out in the bush with no tie downs I lock all control surfaces and tie tail into wind as I've never seen a bent wing strut on the Maule from tail winds like we saw on a bunch of cubs in ANC a couple years ago. If nose into the wind, you could always raise the tail some to get a small negative AOA like when you heel floatplane up on beach as this works well too. I also try to park near a tree line, building, or other obstacle which will deflect some of the wind speed. I see some acft around here tied to 15 gal drums full of water, cement blocks, etc, etc but that would make me really nervous as water in drum weighs 120# each, same with most of the cement blocks in that the acft can fly with that kind of weight almost like nothing there!!

[Hottshot]

most times in sand/loose ground you can dig the tires in and get the neg angle as well as give stability

[aero101]

In wintertime on skis at various lakes around here which are almost always windy, I just put tail into wind with elev deflected full nose down and I've never had a problem. Summertime with dust devils floating around, that can be dangerous, as we had a dust devil come thru here a couple years ago, blew over a cub that was tied down, but not the tail. To make long story short, it picked up the tail, ripped tie down loops right off the airplane wings, flipped it into his neighboring airplane. Cub ended up with very heavy damage, next door C170 not too badly damaged, So guess what I'm getting at, is it all depends upon time of year, geographical location, WX pattern, etc, etc???

[Maule 9V]

An old timer in Honolulu told me once how he would tie down for hurricanes. He set the tail wheel up on the end of a filled 55 gallon drum to limit the angle of the wings and lashed 4 x 4s span wise on top of the wing to break the airfoil. Certainly he tied the plane down as firmly as possible, too.

[AndrewK]

...flipped it into his neighboring airplane...

Reminds me of something I heard from a long-time Oshkosh veteran who has seen his share of storms roll through during the fly-in: "How well your plane is tied down will determine if your plane ends up on top or bottom". Something along those lines anyway. Can be said about last year's Sun N' Fun as well I guess.

[chetharris]

I advocate pointing the plane into the wind. More likely to try to fly, but also the natural orientation of a plane. The only planes I saw damaged after the last wind storm here in Anchorage (gusts to 80 mph) were tailed in. Both of those planes chose to tie down nose into the wind during the next storm.

If I intend to leave the plane I tie it down at all three points --buried deadman, trees, clumps of willow or alder, duckbills, something. Duckbills give me the most piece of mind. Most recently, while hunting near Delta, I chose to dig the wheels in. Like Wup said, not only did it reduce the angle of attack it added stability. The difference was amazing. I might have lost the plane, if I had not dug the front wheels in. It was a long sleepless night --nearby gusts recorded at over 100 mph.

How about those little tie down rings. I am sure they have plenty of strength in tension, but if the tie down ropes are at an angle? I think this is the weakest link in my system most of the time.

[crbnunit]

As someone who has had those rings out recently, I can say they are small but pretty stout. A good side load could shear them but I would worry about the aluminum spar they are screwed into if they did. I do try to orient my off airport tie downs directly under them when possible but almost all the fixed airport tie downs are spaced wider than the rings.

I think I am going to have my wing cover spoilers filled with a Dacron-type insulation, like synthetic sleeping bag insulation, rather than the pipe insulation they were supplied with. The ridged fill makes them a bear to install by yourself but the spoilers are worth having in the wind. The soft insulation would allow them to be rolled up and easier to work with.