Simviation Forum - Don't worry, I didn't crash yet!

Reply #15 - Oct 17^th, 2006 at 10:35pm

beaky Offline
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When I first stick my head into a C172, it's .. " Battery on, beacon on, flaps down".. Then check the fuel gauges for "any" indication (to be later verified with a stick) check the beacon (our tower yells at you if you have a prop spinning and no beacon flashing). It IS on the the "Initial" checklist (flaps extended)...

Anyway.. unless your one guess is right (gust of wind).. I'd suspect that the nose-wheel and rudder weren't agreeing with each other and you had more rudder than you thought during the take-off roll. You'll get that, to a certain extent, when the rubber linkage (that keeps you from snapping the nose-gear when it touches down with loads of rudder in, during a crosswind landing) is worn.. Or.. when one too many students think you need to move the rudder, full deflection each way, while at the tail during walk-around (there's an adjustment for that) Roll Eyes

.. or both. It's not something you can detect during a normal pre-flight. I mean.. if there's enough slop for the nose-wheel to jump left or right, the moment after it lifts... you'd feel it when you tried to taxi at nose-wheel steering speed... and even if it does, a nose-wheel doesn't have enough surface area to over-ride the rudder at at 60+kias. And even if it did.. you'd feel it before the mains lifted.

That really sounds like you caught a gust of wind. And yeah.. the shimmy damper is shot.. and as far as I know.. there's no way to check it out on the ramp, pre-flight. Unless of course it was literally broken. I know I never actually put three fingers on the strut to check travel... and short of intentionally looking for a broken damper.. that's when you'd likely catch it. I do know one thing Grin

I'll be lifting the tail next time I fly a 172.. to take the "tie-down" extension out of the strut...and maybe even put those fingers on it Wink

You learn something every time you fly (and every time you listen to others about their flying)..

Good post...

Good point about the rudder/wheel interface... that's often a factor too, if it's "out of rig". Grin

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Reply #16 - Oct 18^th, 2006 at 1:15am

SilverFox441 Offline
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The CT-133 I worked on years ago used a nosewheel shimmy damper. One of the ground checks was to bounce the nosewheel (push up the nose to unload the strut somewhat)... this has the effect of allowing the damper to show if it is collapsed or over pressurized. In either case the damper will force the nosewheel over or allow it to fall over to full stop positions.

That will also tell you if the nose wheel strut is still OK. Not sure how you would do it in a Cessna... but pushing down on the H-stab might do the trick.

Steve (Silver Fox) Daly

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Reply #17 - Oct 18^th, 2006 at 1:18am

beefhole Offline
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Quote:

The CT-133 I worked on years ago used a nosewheel shimmy damper. One of the ground checks was to bounce the nosewheel (push up the nose to unload the strut somewhat)... this has the effect of allowing the damper to show if it is collapsed or over pressurized. In either case the damper will force the nosewheel over or allow it to fall over to full stop positions.

That will also tell you if the nose wheel strut is still OK. Not sure how you would do it in a Cessna... but pushing down on the H-stab might do the trick.

You could do the exact same thing. If the strut is a little low, I literally get on my knee, put my shoulder under the plane and bounce it a few times-works like a charm.

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Reply #18 - Oct 18^th, 2006 at 8:03am

Chris_F Offline
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Quote:

The CT-133 I worked on years ago used a nosewheel shimmy damper. One of the ground checks was to bounce the nosewheel (push up the nose to unload the strut somewhat)... this has the effect of allowing the damper to show if it is collapsed or over pressurized. In either case the damper will force the nosewheel over or allow it to fall over to full stop positions.

That will also tell you if the nose wheel strut is still OK. Not sure how you would do it in a Cessna... but pushing down on the H-stab might do the trick.

What's the key combo for this procedure in MSFS?

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Reply #19 - Nov 2^nd, 2006 at 1:28am

Boss_BlueAngels Offline
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I've been assisting the mechanics in my flight schools maintenance department, and man have I learned a lot about aviation!!!

One of our airplanes had a shimmy dampner that was in rather poor condition. When he emptied the hydraulic fluid out of it, it was solid BLACK and almost didn't even pour out of the cylinder! Eesh!

Also be sure to pay special attention to the security of your control surfaces. We've recently replaced 2 complete elevators in our 152's. The mechanic asked me to do a preflight of the empennage and when I got back to the elevator I noticed there was the slightest bit of movement that caused a little bit of a rattle. That was caused by a siezed bearing that began to wear away creating the very slightest bit of play. In flight something like this could cause flutter ultimately resulting in complete failure of the control surface. It was such a subtle notice I'm sure a dozen students never even noticed it while moving that elevator. But time after time it slowly began to get worse and worse until they needed to replace it. And by the way, it took THREE of us to get that stupid bearing out to remove the elevator!!

As per the nose strut, like others mentioned just pull down on the nose a bit and check its movement and settling position. The 182's the skydive school use seem to love to sit with that nose strut almost fully extended. All it takes is a little nudge and it settles right down.

I've become quite acustomed to disfunctional shimmy dampners. It's just a matter of taxiing extremely slow, or fast enough to raise the nose and take a little bit of the load off. And that's not because of my current flight schools. I just seem to be the lucky one.

While on the topic of crosswinds as well, I had a real doozy the other day! I was coming in and just starting my flair when I notice the wind sock jump from a dead standstil to completely horizontal! I anticipated the gust and began to lower that wing, added a tick of power and kicked the rudder when I suddenly found myself about 50 feet to the left! Only probelm being the runway is 30 feet wide!!! Everything happened extremely fast but somehow remember getting right back on centerline and greasing a perfect landing. After we exited the runway and were stopped my instructor looked at me with his mouth opened and put his left hand out to give me five and said, "That was some great maneuvering!" It was amazing because I don't even remember really thinking anything, I just saw what was coming and reacted.

My boss was watching and was quite impressed as well. He said during the whone thing I never was more than 5 feet above the ground, including my wingtips when maneuvering.

And that was all in our lovely Cessna 177 Cardinal RG. Man I love that bird!!

The day is always better when you're flying upside down.&&&&www.fight2flyphoto.com&&&&Canon RebelXT&&Canon 18-55mm&&Sigma 10-20mm F/4-6.3&&Sigma 100-300mm F/4-6.3&&Sigma 50-500mm F/4-6.3

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Reply #20 - Nov 2^nd, 2006 at 7:19pm

TacitBlue Offline
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Saint Joseph, Missouri, USA

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Well, I've learned a lot from this thread. I always check the flaps, but I will start checking the nose gear more thoroughly from now on.

...Now if I could just get a permanent job I could start flying again. Roll Eyes

A&P Mechanic, Rankin Aircraft 78Y

Aircraft are naturally beautiful because form follows function. -TB

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