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I am sure this was due to my own ignorance on proper technique, but immediately after landing in a Cessna 172, I applied brakes and some moderate aerodynamic braking and experienced an awful and violent rapid shake of the plane. I let off the brakes but the plane continued to shake for a few seconds.

This caught me off guard and certainly had my anxiety pretty high given I've never experienced this before. I cannot recall at the moment what I did to get the shaking to stop. I believe I simply let off the brakes and tried to steer the plane with the rudder. Again, this took a while (which felt like an eternity and had me wondering if I was going to lose control of the aircraft).

Once the shaking stopped, I tried to just lightly touch the brakes. The shaking started immediately again.

At this point I was very conscious about making sure I was using the most aerodynamic braking as possible and simply trying to steer the plane down the runway with no brakes.

What causes this? Are all Cessna 172s like this? I was advised when talking with a CFI to essentially not use the brakes until I've slowed down significantly.

For background, I'm used to flying the 4 seater Pipers (140, 160, 180, 200) and am transitioning to fly the 172's because my rental location no longer owns Pipers. I have never had this problem with a Piper. I could land, apply maximum aerodynamic braking and a good amount of toe brakes without issue (and optionally continually increasing the braking as the plane slowed more).

If I were to guess, I imagine this is due to the Pipers landing gear being short and stubby whereas the Cessna's gear is much longer and thus probably has more bend in the gear as well as torque it can impart on the aircraft.

UPDATE:

The nose wheel was on the ground. Sounds like a lot of you are thinking its nose wheel shimmy. I'm inclined to think you're right, but I'm surprised at the intensity of it because it was LOUD and things in the plane were shaking pretty significantly.

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  • $\begingroup$ Paved, gravel, or grass strip? $\endgroup$
    – Zeiss Ikon
    Oct 28 '21 at 16:13
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    $\begingroup$ This also happens to the 172's at the place I rent from, and the instructors just say "it's fine, don't worry about it", so I think it's just something that just happens. I don't know why, though. $\endgroup$ Oct 28 '21 at 16:24
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    $\begingroup$ Nose wheel on or off the ground? If it's off the ground, you should avoid braking as the reduced weight on wheels makes it easy to lock them up and flat spot them or cause wheel hop which could be your vibration. Normal procedure is to brake after the nose wheel is down. If the nose wheel is on the ground, see @Jpe61 answer. $\endgroup$
    – Gerry
    Oct 28 '21 at 16:38
  • $\begingroup$ maybe it needs a front-end alignment? :) $\endgroup$ Oct 29 '21 at 21:57
  • $\begingroup$ @ZeissIkon, paved and well maintained. $\endgroup$ Oct 30 '21 at 17:30
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I'm pretty sure you have encountered "nose wheel shimmy".

For reference, see this video on Youtube: c172 M Nose wheel shimmy [sic].

The shimmy can occur for a variety of reason, most likely due to some imbalance in the tire/wheel combo, loose bearings and just the right caster angle induced by your braking (and thus pushing the nose down).

While it may not be a definite sign of an imminent catastrophic failure, the root cause should be investigated and dealt with, as it will get worse over time, and eventally when bad enough, quickly wear down nose gear parts causing it to fail.

Not to use brakes is not a fix to this problem, it's just someone being lazy and cheap, if I may say so.

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    $\begingroup$ Excellent choice of video! Shows how shimmy depends on wheel load and even gives advice on how to repair the issue in the comment below. +1 $\endgroup$ Oct 28 '21 at 17:24
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This shaking is the infamous Cessna nose-wheel shimmy.

It is a result of the bungee connection between the nose wheel and the rudder pedals, which is required due to the way you work the rudder of a Cessna in a side slip landing*. There is a shimmy damper on the nose gear, but they often aren’t maintained as well as they should be, and even in perfect shape they will only reduce it rather than eliminate it completely.

The proper way to handle it is to reduce the weight on the nose wheel, which also improves aerodynamic braking and puts more weight on the main gear, and gradually increase pressure on the brakes as the the plane slows down. Braking will cause the weight to shift back toward the nose gear, so you will need to increase back pressure on the elevator even more to compensate.

For a short field landing, you are forced to accept some shimmy to get the shortest possible (book) rollout distance. You can also raise the flaps to reduce lift and add weight on the mains to increase braking action and add even more back pressure, but I wouldn’t add that distraction until you’ve got the rest of the technique down.

(* Do not crab a crosswind landing in a Cessna like you would in a Piper; learn how to do a proper side slip landing. The pattern work for that will give you plenty of chances to learn how to brake properly too.)

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  • $\begingroup$ Yup, exactly what I thought, too. +1 $\endgroup$ Oct 28 '21 at 17:20
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I worked at an airport with 172 trainers for three years and got my PPL in those planes - they would shake all the time. If you didn't pull back on the yoke after landing, it was pretty common. Once they got to the point that you couldn't stop it from happening on landing or it got rather violent, they would go in and get a new damper on the front wheel.

All of this is to say it's not uncommon, but if it's bad enough to be concerning, go get it checked out. While it's likely a bad damper, it could be something more serious.

Here is a good article from AOPA on this issue: https://www.aopa.org/news-and-media/all-news/2016/september/flight-training-magazine/how-it-works

The important part:

The first time you experience a failed shimmy damper on the taxiway or runway, you’ll think the aircraft is shaking apart. The important thing to remember is that while it isn’t, and you’re safe, you need to get weight off the nosewheel by pulling back slightly on the control yoke. Right now.

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  • $\begingroup$ Welcome to aviation.SE! I edited your answer slightly; please use the quoting markup for quotes, not the preformatted (code) markup. That helps screen readers and other tools work correctly. $\endgroup$
    – Pondlife
    Oct 29 '21 at 16:09
  • $\begingroup$ Welcome! You're doing great work, providing relevant personal experience that directly relates to and answers the question. Keep it up ! $\endgroup$
    – Criggie
    Oct 30 '21 at 23:36
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In the case of disc brakes, braking shimmy can be caused by a brake disc that is warped or unevenly worn. I don't know if Cessna nosewheels have disc or drum brakes, but this is the most common reason for brake shimmy in ground vehicles, like my old Suzuki GS1000 motorcycle.

By the way, the technical name for nosewheel shimmy due to elasticity of the tire or the steering mechanism is caster instability.

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    $\begingroup$ No brake at all on the C172 nose wheel. $\endgroup$
    – StephenS
    Oct 28 '21 at 20:17
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    $\begingroup$ @StephenS, good, then it is not brake shimmy but caster instability. $\endgroup$ Oct 29 '21 at 1:41

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