Curious about the real story behind this...

http://www.chicagotribune.com/news/chi-ap-il-planeaccident-cah,0,2957354.story

Did it just fail on landing because of a stress crack? Sheared hardware?

Or was it after they did a pirouette and got out and said: "Umm, our landing gear failed. Yeah...that's it."

I, as many more on here can tell you this.....I'm about the same vintage as a 180 (1953) and my gear legs are starting to crack also. Time will take its toll on everything. Maybe a cocked landing or maybe it was just old?

From a recent Safety Alert For Operators (SAFO) bulletin I received from FAA:

FAA Issues SAFOs on Tundra Tires
On May 24, 2010, FAA issued two SAFOs (Safety Alert for Operators), recommending important risk-mitigating actions for pilots. The first, SAFO 10007, provides information on the potential for problems with airplanes that have oversized (tundra) tires, ski, and wheel/ski configurations. There have been 32 documented accidents caused by failure of the landing-gear leg near the attachment holes of the axle on airplanes with these modifications. Realizing the wide range of variables that affect these airplanes (e.g., vibration, drag, loading) and the difficulty of predicting their impact, FAA recommends pilots adopt a proactive approach towards reducing risk with more careful and frequent inspection of the axle attaching holes for cracks, corrosion, and any other defects

Further: http://www.faa.gov/other_visit/aviation_industry/airline_operators/airline_safety/safo/all_safos/media/2010/SAFO10007.pdf

This incident fits the bill: spring gear, old plane, and I'd wager, oversize tires.

YB

anybody know what happened to the 180 on mile high?...

Probably more gear box failures than gear leg failures in 180 series Cessnas.

gb

This report says a wheel & tire came off. No telling the way the media get's things wrong.

http://aviation-safety.net/wikibase/wiki.php?id=75297

Yellowbelly wrote:
This incident fits the bill: spring gear, old plane, and I'd wager, oversize tires.

YB

I love the FAA and the Mentality they create.....

Yess it is the Big tires that caused it not the fact that the aircraft was made in the 50's and has several thousand TO's and Lndg's in cross winds and other factors that have stressed the gear over the last 60 years....... Yep it was the BIG TIRES!!! give me a break and use some COMMON SENSE



Sorry, Rant over .... Sorry YB not picking on you just irritated with the FAA on this issue


(Yes I know it was built in 1979 just trying to make a point I guess)

Boy what a bunch of idiots in the world, most woking in the gov. Everything is subject to failure and time for sure doesn't help. Even my once hard body is falling apart or is that my hard head

In my opinion (and I'm a low time pilot), I can't see how oversize tires can be much of an issue for gear legs. I believe larger tires with the right pressure has more cushioning effect and provides less vibration and jolting on hard bumpy surfaces. Just plain ole common sense to me.

The only issue I can maybe see with oversize tires is trying to turn your plane in a very tight radius on pavement or dirt. But then again, I don't believe the forces are that much to cause harm the the gear legs. I think the tires will take up most of the abuse.

Please keep in mind, I'm not trying to start crap with anyone here!!

I'll be looking for the NTSB report on this one, too.

I'm actually quite surprised that the FAA issued a SAFO for "tundra" tires if they really believe that they present an undue stress or hazard to an aircraft. This is just seems to be in conflict with the SOP for making mods and additions to aircraft such a difficult process. It's as if their policy is to acknowledge a potential problem so that the owner can in effect "accept the responsibility of the potential hazard." Why can't that same attitude hold for field approvals or even less serious mods?

I don't think you have any PR issues to worry about, Wup.

Who holds the STC for hollow steel axles these days? When I bought mine it was Airframes, Inc, but I'm not sure they still make them.

I do know what I'm going to say though if I ever groundloop and rip a gear leg off... "that gear leg ripped off at touchdown."

Hottshot wrote:

Yellowbelly wrote:
This incident fits the bill: spring gear, old plane, and I'd wager, oversize tires.

YB

I love the FAA and the Mentality they create.....

Yess it is the Big tires that caused it not the fact that the aircraft was made in the 50's and has several thousand TO's and Lndg's in cross winds and other factors that have stressed the gear over the last 60 years....... Yep it was the BIG TIRES!!! give me a break and use some COMMON SENSE



Sorry, Rant over .... Sorry YB not picking on you just irritated with the FAA on this issue


(Yes I know it was built in 1979 just trying to make a point I guess)

I watched a 170 bounce sideways almost hit a wing tip 6 different times before on the 7th try get it on the ground and stopped. The next day at another airport the tore the gear off.

They blame it on the gear.........those of us that watched the day before are quite sure the gear couldn't fix stupid

mr scout wrote:
I watched a 170 bounce sideways almost hit a wing tip 6 different times before on the 7th try get it on the ground and stopped. The next day at another airport the tore the gear off.

They blame it on the gear.........those of us that watched the day before are quite sure the gear couldn't fix stupid

Knowing how hard I've been on my gear at times...and multiplying that by the lifetime of the aircraft, I stand amazed that these old gear legs hold up as well as they do.

Maybe the Fat Tires increase the brave factor, and therefore ya land at more places that might have a bad effect on the gear.

Coyote Ugly hit the nail on the head. Put a set of big tires on an airplane, and the airplane is very apt to go places it would never have gone before.

Also, remember that MASS is largely what counts here as well. So, even on takeoff from a smooth surface, the gear rebounds. Hang more mass out there, and you get more rebound force. Now, do the same thing in an off airport, rough environment, and the forces can be huge, both in extension and in rebound.

Now, put a set of skis on that airplane, or better yet a set of retractable wheel skis, which weigh well over 60 pounds a side. And, take that plane into some rough snow conditions.

An example is the rebound forces in the Husky gear. Aviat built a longer gear to adapt the wheel skis, and the combination of ski weight and a slightly longer arm started bending cabanes, not in extension (impact) but in rebound.

The failure mode in Cessnas that the FAA is describing here has been known by the FAA for decades. I know of at least one VERY conciencious commercial operator who had a failure of this type on a 185. That plane got worked hard on big tires and skis. The operator had the gear legs tested annually, but they still broke.

As others have noted, pilots tend to be pretty hard on these things, even without the additional mass out there, but adding a lot of mass on the end of those spindly little legs DOES increase the forces involved.

Fortunately, at least so far, the FAA hasn't decided to go with an AD requiring NDT of the gear every year. THAT would be a MAJOR PITA, and I doubt it would alleviate the problem in any case.

By the way, the failure point here is between the bolt holes that hold the axle to the gear leg. They crack between bolt holes. It's not real common, but as someone also noted, these gear legs are pretty darn old in general, and have been subjected to a LOT of stress.

MTV

[Knowing how hard I've been on my gear at times...and multiplying that by the lifetime of the aircraft, I stand amazed that these old gear legs hold up as well as they do.[/quote]

At least yours was never on skiis, and I suspect that crosswind gear was easier on gearlegs than fixed. Although a crabbed landing in a good crosswind did give it quite a jolt.

Oh yes, and I always made perfect landings. Ha!

1SeventyZ wrote:
I do know what I'm going to say though if I ever groundloop and rip a gear leg off... "that gear leg ripped off at touchdown."

What do you mean "if I ever ground loop"?........
HC

jomac wrote:anybody know what happened to the 180 on mile high?...

Heard two different stories and there maybe more. He over shot the landing and intentially ground looped to stop, damaging the wind and tail...or....He landed just fine, but taxiing he banged his plane up.

What I wonder is, who want to be the test pilot that who fly the plane off???....or...How much would it cost to helicopter it off???

I shedded my right gear on my Pacer a few years back when a weld broke...now I've got "tundra tires" and no problems...or maybe I did a better job welding it this time around.

Hey Steve,
Where did the weld brake on your pacer? I don't remember when I looked at your plane if you have the same added strengthening bar that I have on my pacer or not. If you do, did you have it on there when the weld broke? I'm just wondering where I might need to worry about.
Charles

short field landing @ KNYL easy on the gear

A few lifetimes ago, I worked on the design of the F-18. There were two tests we dreaded: the landing gear drop test and the return to ship with stores and fuel. These seemed to generate the most intense loadings for many parts of the airframe. Not hard to see why. (I think they got the idea for this test from one of my very own landings)



In real time:




Wup: don't worry! A set of your tires is still at the top if my LUST list, even if they introduce so many new variables that the FAA can't make an AD out of them.

But MTV is right. You can't hang a couple of packages like that out there and do the stuff they allow you to do without any impact. Just be aware... and look a bit more carefully DOWN THERE when you do your annual.

YB