Structural Failure

Snowmass said:
and and tie down yanking stresses are trivial compared to flight stresses.
Click to expand...

Really? Maybe you should contact these people and suggest another factor for this:

upload_2022-3-10_16-38-56.png

A close-up reveals that the struts buckled. Tiedown forces did that.

upload_2022-3-10_16-38-25.png

https://aviation.stackexchange.com/...ich-is-tied-down-be-protected-from-a-blizzard

People forget that wings are designed to lift airplanes. The wing of a 182 is designed to lift that airplane, at gross, at anything above stall speed if the nose is high enough, and the nose can rise in a strong wind. 2950 pounds for a 182N. Now, lets raise that windspeed to way above stall speed and see what that wing will generate. Maybe 5000 or 6000 pounds in a real wind. That's why I get so annoyed at owners who use tiny or rotten ropes to anchor their expensive airplanes. Or those who use chains, when chains have no give to them so that considerable damage is done when the airplane starts bouncing around. And don't give me the make-the-chains-tight baloney; if tires lose pressure they're not tight anymore, and they become slide hammers.

We've seen damage in wing and strut bolt holes from undertorqued bolts that allow the wing to move relative to the fuselage. Wind can do that too. And if the wind can do that, it's yanking on the strut attach points.

Besides that, I can imagine the FAA guys thinking that if there's a calendar component. there's a better chance that someone will find the crack, as annuals aren't always all done by the same person. Different eyes find different things because they are feeding minds that are alert or complacent or sleepy or distracted. Human factors.
 
Dan Thomas said:
Really? Maybe you should contact these people and suggest another factor for this:

View attachment 105324

A close-up reveals that the struts buckled. Tiedown forces did that.

View attachment 105323

https://aviation.stackexchange.com/...ich-is-tied-down-be-protected-from-a-blizzard

People forget that wings are designed to lift airplanes. The wing of a 182 is designed to lift that airplane, at gross, at anything above stall speed if the nose is high enough, and the nose can rise in a strong wind. 2950 pounds for a 182N. Now, lets raise that windspeed to way above stall speed and see what that wing will generate. Maybe 5000 or 6000 pounds in a real wind. That's why I get so annoyed at owners who use tiny or rotten ropes to anchor their expensive airplanes. Or those who use chains, when chains have no give to them so that considerable damage is done when the airplane starts bouncing around. And don't give me the make-the-chains-tight baloney; if tires lose pressure they're not tight anymore, and they become slide hammers.

We've seen damage in wing and strut bolt holes from undertorqued bolts that allow the wing to move relative to the fuselage. Wind can do that too. And if the wind can do that, it's yanking on the strut attach points.

Besides that, I can imagine the FAA guys thinking that if there's a calendar component. there's a better chance that someone will find the crack, as annuals aren't always all done by the same person. Different eyes find different things because they are feeding minds that are alert or complacent or sleepy or distracted. Human factors.
Click to expand...

Equivalent of -G's?
 
Mxfarm said:
Equivalent of -G's?
Click to expand...
No. The wing wasn't pushing "down." The chains or ropes were, though, and when the airplane was pushed forward by the wind the stresses on the struts buckled them. A whole bunch. The text says the spars were broken but I don't see any bending in the wing. Probably torn or twisted, though. There was a lot of give to drop the wings that much.

Way back in the early '70s not long after I got my PPL, an 85 MPH windstorm tore across the airport and demolished 13 airplanes. Broke ropes, pulled anchors out of the ground. Might have broken the airplanes before they were rolled up into balls. It was a sad sight and I still have pictures of the devastation. Makes a young guy think about how those wings can lift so much. Some of those owners never flew again. They had no hull insurance and couldn't afford another airplane.
 
Adam Weiss said:
This is why I always have a little nagging in the back of my mind.
Last summer I was flying out West CAVU and hit the worst turbulence I’ve ever felt. It only lasted a fraction of a second, but I hit my head so hard on the canopy that it drew blood where my headset dug in.
I can’t even guess how many g’s that was, but certainly way more than my RV-9 is rated for.
That got me thinking on almost every flight afterward…what stress did I cause that I can’t see?
Click to expand...

I was lucky enough to get checked out in a civilianized T-34 Mentor as a new private pilot with only 100hrs. One day, I was flying it about 1,800'agl and hit "bump" like you describe. It felt like I'd run over a speed bump, and my head hit the canopy.

Since I was on my way back anyway, I made a normal landing, no problem. I did write up the possible "over-g" in the discrepancy log and wrote down a detailed explanation of what happened.

I got a call later on from the flying club manager. He said that he really appreciated me writing it up, as one of his biggest fears was that someone would bend the airplane and not tell anyone. He said he really doubted I pulled enough G to warrant a write up. But, he would have the mechanic look for tale-tell signs of over-G, and if he didn't find anything, they were just going to sign it off.
 
Therookguy said:
So I can take comfort in the fact that I'll join the POA hall of fame if I snap the wing of a 182?
Click to expand...

Take a tip from Trevor and take a chute with you so you'll be around to enjoy your HOF status ...
 
Getting out of a rapidly rotating airplane would be harder than one might think. I think. One wing gone means the other makes the whole affair spin like mad. Now you're dealing with centrifugal forces in trying to get out.
 
You must log in or register to reply here.
Back
Top