This happened on my XC flight today, need some thoughts on it!

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Nick Kan

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cavsfan2016
I am a fairly new private pilot at around 80 hours of total time. I decided to take my mom up for the first time from KBKL to KERI and back. My landings have always been solid with a couple hiccups here and there as everyone usually has and in my recent flights my landings were good as well. I flew a 1978 C172 today. Upon landing at KERI, my approach speed was just fine at around 66-68 knots, flaps down carb heat out, all configured for landing. Upon touchdown though, we bounced. Now I know bouncing sucks but its just an inconvenience. When we finally touched down I noticed something weird. I am not at all on the toe brakes and using aerodynamic braking but as soon as I rest the nose down the plane just starts shaking like crazy. I remember this happening in my training with my instructor one time when the plane started shaking but in this case my feet were on the toe brakes and my instructor yelled at me to get my feet off the brakes, clearly I was applying too much pressure. But, this time my feet were NOT at all on the toe brakes. I thought maybe the parking brake somehow got activated but no, it was in the off position. The same vibration happened on takeoff as well and the exact landing and vibration also happened back at KBKL. And again, speed, altitude and everything were perfectly fine.

Does anyone have any ideas on what this good be or what the reason is for it?

Did I do something wrong? Did I miss anything?

I was thinking that the parking brake may have somehow still been activated even though it was off, further explaining the bouncing and vibration.

I appreciate any thoughts and advice!! Happy Holidays:)
 
Brad Z said:
What was your speed over the fence/ over the numbers?
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Certainly less than 66, I didnt take a look right before touch down but my power was idle so I doubt I caught any more additional speed.
 
Like stated above, nose wheel shimmy. Lots of posts you can search through for good info. Make sure you’ve got the yoke/elevator all the way back in the mean-time, especially on roll-out and high speed taxi.
 
Nose wheel shimmy is pretty common, but usually fixable with a little effort. Most of our little planes have a damper, which is basically a tiny shock absorber that keeps the nose wheel from shaking. They leak their fluid or otherwise get worn out and stop doing their job. It'd be worth writing it up and the owner can replace it. The only other thing you can do is hold the nose wheel off as long as possible.... it will be less pronounced at lower speeds.

Bounced landings are either excessive airspeed or excessive sink rate. If you don't flare your vertical speed can cause the plane to rebound of the pavement. Sounds to me like maybe you didn't flare enough and landed flat. Springy cessna gear, as I understand it, is less forgiving of this than piper oleos. If it makes you feel any better, I landed a bit flat Saturday and bounced a bit. You'll always have stinkers... that's why the perfect ones feel so good.
 
I like to land with extra speed (75-80knots) then raise the nose to bleed the speed off in ground effect before touching down. It’s difficult to master but practice makes perfect. You can consider doing 3 take offs and landings prior to bringing a passenger in the plane so the feeling of landing is recent and your passenger doesn’t freak out when they get in and experience a landing. Advice from a similar newbie, take it with a grain of salt.
 
mandm said:
I like to land with extra speed (75-80knots) then raise the nose to bleed the speed off in ground effect before touching down. It’s difficult to master but practice makes perfect. You can consider doing 3 take offs and landings prior to bringing a passenger in the plane so the feeling of landing is recent and your passenger doesn’t freak out when they get in and experience a landing. Advice from a similar newbie, take it with a grain of salt.
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A huge grain. Maybe the whole shaker. You can get away with this on a long runway, but if you try it on a short one you'll run off the end. The book landing speed already has a 30% margin over stall at max gross.... it's plenty fast.

Coming into ground effect that fast will take forever to get slowed down and put you in the perfect conditions for a PIO (or porpoise) that will end with a prop strike and maybe worse.
 
Jim K said:
A huge grain. Maybe the whole shaker. You can get away with this on a long runway, but if you try it on a short one you'll run off the end. The book landing speed already has a 30% margin over stall at max gross.... it's plenty fast.

Coming into ground effect that fast will take forever to get slowed down and put you in the perfect conditions for a PIO (or porpoise) that will end with a prop strike and maybe worse.
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I typically fly at airports with longer runways, 6000’+ usually and use less than half. What would cause a prop strike?
 
exncsurfer said:
Is it?

View attachment 102753
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Nope. Someone on the internet is wrong. Shocking, isn't it? :eek2:

Though booze can be both a damper (has a subduing effect) and a dampener (getting things wet after it has damped your reflexes so you spill your drink)... :cheers:

Can we milk this discussion of nosewheel shimmy as long as a bunch of tailwheel pilots can discuss tailwheel shimmy and how to fix it?
 
mandm said:
I typically fly at airports with longer runways, 6000’+ usually and use less than half. What would cause a prop strike?
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Ever seen a video of a pilot induced oscillation? If not look it up. Coming in too fast and letting the plane touch down before its done flying is the setup. A 172 should need <1000'.
 
Nick Kan said:
well like I said I was at around 66 knots at approach isnt that fine?
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It's not always about your speed, especially your speed on final. The only thing excess speed should do is extend your float...unless you force it down. OTOH, it could be you touched down nosewheel first which will almost always create a bounce regardless of being fast or slow.

I wasn't there so I can only poorly guess what happened.
 
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Hold the airplane off until it won't be held off any longer.

Dampener as in dampen the motion. But damper is ok too.
 
mandm said:
I typically fly at airports with longer runways, 6000’+ usually and use less than half. What would cause a prop strike?
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Trying to force the airplane on the runway or trying to compensate for a bounce by releasing back pressure. Keep that nose wheel off the runway during the flare to landing.
 
That's the ol' Cessna Shimmy! If it happens once and goes away, work on your landings. If it's a recurring problem, write it up for maintenance (and still work on your landings!) I had it happen recently, but my landing was...less than perfect. I chalked it up to pilot error and went on about my business. Then 2 other club pilots complained about the same thing with one reporting to the maintenance chief that he didn't feel the aircraft was safe to fly. Since I wasn't having the issue repetitively, I volunteered to do the ferry flight to the A&P we use, only to have it happen upon landing at the A&P's field. No big deal, they repaired it and it's fine now.
 
Dana said:
Nope. Someone on the internet is wrong. Shocking, isn't it? :eek2:

Though booze can be both a damper (has a subduing effect) and a dampener (getting things wet after it has damped your reflexes so you spill your drink)... :cheers:

Can we milk this discussion of nosewheel shimmy as long as a bunch of tailwheel pilots can discuss tailwheel shimmy and how to fix it?
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Who is wrong? According to the Cambridge dictionary, those two words are synonyms. So maybe they're both right.

Now, back to the shimmy discussion and 85knot into the flare in the 172....
 
As we've learned on all the Cessna forums the cause of nosewheel shimmy is more likely something other than the dampener (that's what Cessna calls it in the 63-74 100 Series parts manual). Check the torque link wear/play and bushings and check nosewheel for roundness, flat spots, and balance.
Slow down, keep the yoke in your gut, and be light on the nosewheel on landing. Stay off the brakes until you've really slowed down.
 
Bounces I've seen were caused by two things: sink rate and plenty of flying speed left. Hefty sink rate might mean you misjudged your flare. Was it a 3 point bounce? Shimmy, shimmy, shake, shake. Be sure and write it up if it is a rental or school house airplane.

See above, too.
 
Wh
Nick Kan said:
I am a fairly new private pilot at around 80 hours of total time. I decided to take my mom up for the first time from KBKL to KERI and back. My landings have always been solid with a couple hiccups here and there as everyone usually has and in my recent flights my landings were good as well. I flew a 1978 C172 today. Upon landing at KERI, my approach speed was just fine at around 66-68 knots, flaps down carb heat out, all configured for landing. Upon touchdown though, we bounced. Now I know bouncing sucks but its just an inconvenience. When we finally touched down I noticed something weird. I am not at all on the toe brakes and using aerodynamic braking but as soon as I rest the nose down the plane just starts shaking like crazy. I remember this happening in my training with my instructor one time when the plane started shaking but in this case my feet were on the toe brakes and my instructor yelled at me to get my feet off the brakes, clearly I was applying too much pressure. But, this time my feet were NOT at all on the toe brakes. I thought maybe the parking brake somehow got activated but no, it was in the off position. The same vibration happened on takeoff as well and the exact landing and vibration also happened back at KBKL. And again, speed, altitude and everything were perfectly fine.

Does anyone have any ideas on what this good be or what the reason is for it?

Did I do something wrong? Did I miss anything?

I was thinking that the parking brake may have somehow still been activated even though it was off, further explaining the bouncing and vibration.

I appreciate any thoughts and advice!! Happy Holidays:)
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You didn’t hold the plane off after the round out and then moved the control wheel forward instead of keeping it full aft.
 
Well ... if it's mom's first ride in a small plane and she doesn't know any better ... :D
 
If the stall horn wasn’t going off before your main wheels touched the ground then you landed with too much energy. It had to get dissipated somehow, which was a bounce. Stall horn in a 172 = touchdown speed indicator, unless there’s a wing sheer/gusty condition. Then add knots appropriately.
 
I've never had an issue w/ bouncing but I have bouncing's cousin: ballooning. My CFI determined the issue to be my not being able identify when the plane is ~1 foot off the runway. To solve this problem, he would have me fly down the runway at 1 foot and not touch down until he instructed me to do so. Do this a couple of times and it will burn into your brain what the front and side windows look like at 1 foot. Also, the exercise gets you comfortable adding a little power on landings. Power is sometimes needed on landings going south and you need a little more time to stabilize before settling down on the runway.

Regarding the shimmy, I was taught it's good practice to hold the nose wheel off the runway as long as possible. If you experience shimmying when you cannot hold off the nose wheel any longer then there's a mechanical issue. Also, holding the nose wheel off enables you to slow down faster and gives you greater braking authority (should you need it).
 
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The expensive "Lord" shimmy damper and another $400 in parts and labor will fix the shimmy.

Don't sweat it...................you did nothing wrong. Bad design.
 
A common phenomenon. You’re a perfectly functioning adult, until you get around your parents again. Also, if you put it on the pavement before the airplane decides to quit flying, it’s actually a controlled crash. But, no injuries or damage, so it’s still a great landing, and mom is still proud.:)
 
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