Hammer wrote:I've found putting rocks into a heavy net bag makes a good anchor, providing there are rocks where you fly. I like it because it weighs almost nothing and it's actually pretty easy to put a couple hundred pounds of rocks together

Also doesn't take much wind for your wing to lift several hundred pounds of rocks, and off we go!!!!!!!!!!!!!

Gotta have more weight/force holding things down than you can stuff in the airplane and make it fly.

Gump

Gotta have more weight/force holding things down than you can stuff in the airplane and make it fly.

I have a Cessna 140. So like I said, it's pretty easy to put a couple hundred pounds of rocks together...

Hammer wrote:

Gotta have more weight/force holding things down than you can stuff in the airplane and make it fly.

I have a Cessna 140. So like I said, it's pretty easy to put a couple hundred pounds of rocks together...

Just be careful. That C140 will still lift a couple thousand pounds with the wind blowing hard.

Gump

ccurrie wrote:Hey i already posted the whitehorse dc3 pic you thief.

1. Different pic, if you look close
2. I'm not sure I actually posted it (without moderator help), since I'm still not sure I've got the knack for doing it- that's why the pics are so damn large. Sorry about that.

So there

Let's see--gather up "a couple hundred pounds of rocks" for your tiedowns.

Now, a Super Cub, at say...1150 pounds empty, is certified for 1750 pounds, or 2000 with the wip kit, and the same wing readily lifts 2300 pounds of aircraft at 44 mph.

So, consider that your "couple hundred pounds of rocks" is basically the equivalent of a full load of fuel in that aircraft, and no passengers or pilot...

Uh, I'll take the earth anchors any day, UNLESS the "soil" is simply such that you can't drive them in. Bags of rocks better be REALLY big to really have any effect in a no joke wind.

The spoiler covers is the other half of that equation. Put in earth anchors, then if it really blows add the spoilers.

I'm talking WIND, not, as they refer to them around here--breezes .

MTV

mtv wrote:The spoiler covers is the other half of that equation. Put in earth anchors, then if it really blows add the spoilers.

The problem I've personally seen with spoilers, is that in a really big and really prolonged wind, if a strap breaks or a seam gives way and things can move, the canvas/nylon will act like a saw. It will cut through a wing like a hot knife through butter.

Gump

A lot seems to have to do with how taught your lines are. If they have slack and the plane gets to bucking, the dynamic loads are going to be far greater than the original static load caused by the wind alone. I have a bunch of pictures from Lake Hood and Anchorage Int'l a few years back when the winds topped 100 mph in the tower. The planes that really got balled up seemed to be the ones that were beating against their tie-downs, getting airborne, and then bouncing back down. My friend's Helio Courier was in danger of losing a strut-mounted attachment ring, or having it deform. If it had started allowing the wind to lift the plane just a little bit I don't think that airplane would exist today.

I will post some of those Lake Hood pics, but I promise you guys I'll figure out first how to not make 'em so big.

I have heard of another old-school technique used mostly in Canada, which I have never actually seen done. Apparently a plane was tied down very loosely, from the front, and allowed to fly itself any time the wind got strong enough. The theory was that it would face into the prevailing wind every time, and settle back down softly to earth whenever the wind subsided. Anybody ever actually seen this technique employed?

-DP

denalipilot wrote:I have heard of another old-school technique used mostly in Canada, which I have never actually seen done. Apparently a plane was tied down very loosely, from the front, and allowed to fly itself any time the wind got strong enough. The theory was that it would face into the prevailing wind every time, and settle back down softly to earth whenever the wind subsided. Anybody ever actually seen this technique employed?

I watched a C206 in Barrow ride out several days of 100+ MPH winds while not being tied down. Thing bounced up and down like a yo-yo, and beat a 15 foot diameter, three foot deep hole in the snow, and just basically weathervaned itself as the wind changed direction during the front passage. It was ugly to watch, and the owner of that flying service was, and still is, a major dipshit.

If I can, I use ratchet straps, multiple ground anchors, and pull off ALL covers and blankets if a big blow is expected. I also gust lock each surface, and use a clamp-style yoke lock, not the seat belt. Another concern in securing for big wind is the doors. I like to tie 'em from the inside and crawl out the baggage door if at all possible.

Gump

A guy at an airport I drop into pretty often keeps at least one airplane tied down permanently to a pair of 5 gallon buckets full of concrete. Don't know the weight but imagine it's less than 100#. Looked very inadequate to me.

Back in 2003, I think it was, there was a serious wind storm in Anchorage that lasted a couple days. I remember hearing that MRI controllers evacuated their tower when winds topped 100 mph. Luckilly my plane was nowhere near the area, but an acquantaince lost a Supercub and a C185 that week, and a good friend came awfully close to losing a Helio Courier. I made a gallery of pics that I took then, mostly from Lake Hood, and a few over at International. Here's a preview so you can walk away now if you don't like the sight of carnage...

If you want more reasons for good tie-downs, here's the gallery:
http://www.backcountrypilot.org/gallery ... ?album=396

All that Carnage just makes me sick.

I am headed to the hanger to install some tie downs just in case.

I carry 5/8 Vectran pull line rope. 2800lb work load 5000lb non lift and 12000 break strength

Two years ago due to a storm I couldn't get home and had to land down in Gumps neck of the woods.

The nylon ropes the airport there broke 2 on each side. Now I always just use mine no matter where I tie down.

I cant imagine the feeling of going out to your plane and having some other persons bird perched against yours.

That would be almost as bad as when I bought an airplane in Texas, paid for it and couldn't pick it up for a week during which a tornado had its way with it. But that's an over a beer story.

mr scout wrote:I cant imagine the feeling of going out to your plane and having some other persons bird perched against yours.

Lesson here is to carry enough Vectran rope for all the planes you tie down next to

mr scout wrote:All that Carnage just makes me sick. I cant imagine the feeling of going out to your plane and having some other persons bird perched against yours.

Hey Floyd, when you swing through here you'll see how I tie down. I am more than fussy and it's probably a ten minute process each and every time I put her to bed for the night. Longer if I'm pulling on covers.

If I'm traveling I won't park near a sloppily tied down airplane. Like you say, I don't want to go out to the airport in the morning and see some guy's airplane on mine. Just no excuse for it.

I carry ratchet straps and four 30' sections of new kernmantle rope with me, along with the assorted locks and chocks. I never trust an airport rope. Even worse are those gang cables to tie down to. Useless...

Gump

It's also important to note that many of those airplanes were damaged largely (or completely) because they were tailed into the wind.

If you get caught in a huge wind from the rear of your plane, you have a serious dillema: Untie the plane, and try to turn it into the wind, or attach some 2x4s to the struts and hope for the best.

In fact, I've seen a lot of this kind of damage simply because people didn't take the time or effort to go tend their airplanes during a big blow.

I once was sitting in my car, tending airplanes all night in Kodiak, when the plane next to mine started to collapse the rear strut on one side. I got out and put my back under it. Fortunately a police officer came by a few minutes later and I told him to go get the owner and tell him to get out here and take care of his airplane. Never even got a thank you out of that one--guy was pissed about being rousted at 3 AM.

That ANC blow caught everyone by surprise, and it wasn't windy in the rest of town, but it was well advertised on radio and TV.

MTV

Interesting pictures and discussion.

What was the failure mode of the aircraft that have their wings collapsed downward? Did the tiedowns fail the spars/struts?

Several decades worth of tying down sailplanes in very windy places have convinced me that it is critical to get the angle of attack as low as possible in high winds. This action significantly lowers the amount of force the wings produce for a given wind speed.

I have landed a sailplane in winds+gusts that were greater than stall speed, and it is possible to unload the wing by keeping the tail up with forward stick (down elevator). I was essentially flying the ship on the ground until the cavalry arrived.

Based on this experience, I wonder if full down elevator might save a marginally tied down airplane. It might beat the hell out of the tail while jumping off and falling back to the ground but might save the rest of the airframe.

What thinks ye?

MarkGrubb wrote:I wonder if full down elevator might save a marginally tied down airplane.

What thinks ye?

The newer Cessnas use the pin thru the yoke with forward stick, but those of us with older airplanes don't have a good way to secure full down elevator.

I cinch things down tight and back-up knots the best I can, and use a clamp yoke lock I found at Aircraft Spruce to secure pilot/co-pilot sides of the yoke. I've weathered some 60-70 KT winds since I've been down here at Hawthorne, and airplane will rock a little with the give in the tires, but all in all has been pretty much solid.

My theory is wham-bam with a loose tie down is a whole lot more stressful on struts and wings than a steady pull. I've gotten into it with FBO's when they stand there and watch me ratchet the airplane down tight on their ramps. "Too much pressure," "Airplane needs to flex," they tell me. I just ignore them, tell 'em it's my airplane and I'll tie it down the way I want to. That tie-down ring is designed to hold 2,000 steady pounds. Slam a few G's worth of weight in a wind and something's gonna break.

Gump

GumpAir wrote:

MarkGrubb wrote:I wonder if full down elevator might save a marginally tied down airplane.

What thinks ye?

"Too much pressure," "Airplane needs to flex," they tell me. I just ignore them, tell 'em it's my airplane and I'll tie it down the way I want to. That tie-down ring is designed to hold 2,000 steady pounds. Slam a few G's worth of weight in a wind and something's gonna break.

Gump

And most of the ones doing the telling have never owned a plane in their life.
I have had a couple get testy when I cut there junk polypropylene rope off the eye's so I can use my own rope.

Mark,

THe airplanes with the wings failed downward were exposed to winds from the tail. A tailwheel airplane parked tail into the wind puts a LOT of stress onto the top of the wing. Typically, and as is graphically illustrated in several of those pictures, the rear lift strut fails first, allowing the wing trailing edges to fail downward. It gets really ugly from there.

Obviously, a seaplane parked for winter is a little tough to turn around in a big wind, sitting on the bank. One reason I never liked leaving a plane on floats over winter.

MTV

I know you can't take your hanger with you, but this whole discussion helps justify the expense of one. External gust locks on all of the controls is essential if you leave it outside. Locking the yoke helps, but the entire control system is subject to gust loads and wear. Lock the control surface and you save the control system from a lot of stress and wear.
Oh and sometimes you can get them to park the fuel truck in front of your aircraft and it is a pretty decent wind block.

a64pilot wrote: Oh and sometimes you can get them to park the fuel truck in front of your aircraft and it is a pretty decent wind block.

Our county guys here are real good about keeping an eye on forecast winds, and will park a dumptruck in front of the airplane if it looks like things are going to get nasty. And, if I can, I still go down to the airport and sit it out in or next to the airplane. Too easy for stuff to break or come loose.

Gump