Hard landing vibration.

[IvoryM]

Hello,

I have a 1965 M20E Super 21 with a manual landing gear and manual flaps. I came in for a landing today and it wasn't quiet set up just perfect and I bounced one time fairly hard. As soon as The tires bounced off the runway the plane got a real bad vibration. I gave it full throttle released the flaps hit the brakes and retracted the landing gear and the vibration immediately stoped. I flew the pattern landed and everything was perfect. I took it back to the hanger checked everything and everything looked great. Does anybody know what that vibration could've been? Is it possible that the tire flattened a little bit when I hit the runway and that was what the vibration was until I hit the brakes and stop the wheel from turning?

Thanks,

Mitch

[DonMuncy]

I suspect it is a wheel spinning. It happens very often on a bounce.

[Mooneymite]

I agree.  Wheel spin-up.

 

If it stopped when you applied brakes, I think you found the cause.

[Lood]

If the vibration was purely due to the wheels spinning, you would also have had the same vibration during the take-off run or just after take-off, before you tuck the wheels. My guess would be that you might have created a flat spot/s as a result of the hard landing, leaving the wheels substantially out of balance.

[IvoryM]

If the vibration was purely due to the wheels spinning, you would also have had the same vibration during the take-off run or just after take-off, before you tuck the wheels. My guess would be that you might have created a flat spot/s as a result of the hard landing, leaving the wheels substantially out of balance.

[IvoryM]

No flat spots on the tires because when I came back around for my second landing and landed there was no vibration at all. I checked the tires and landing gear once back in the hanger and they were okay. The vibration was only immediately after the hard bounce and only until I hit the brakes and retracted the gear and did not Vibrate after that.

[PTK]

I gave it full throttle released the flaps hit the brakes and retracted the landing gear and the vibration immediately stoped.

Mitch, what do you mean by "released the flaps". Do you mean you poured the coals to her and cleaned up the flaps?

[captainglen]

Definately wheel spin. Even after a normal takeoff it a good practice to tap the brakes just before retracting the landing gear.

[IvoryM]

Mitch, what do you mean by "released the flaps". Do you mean you poured the coals to her and cleaned up the flaps?

[TWinter]

Uh oh, I see the great "brake tap or not tap" for wheel spin debate coming

[IvoryM]

PTK,

You speak my language! Yes I poured the coal to her and cleaned up the flaps.

Thanks,

Mitch

[Marauder]

Mitch - look at the bright side. This poor guy landed at my airport with his brakes on and he didn't get away so lucky.

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[MooneyPTG]

Remember...if you don't wreck the plane it was a great landing:)

[Danb]

That means when I landed at Detroit yesterday I had a great landing. Boy I need practice...

[fantom]

Mitch - look at the bright side. This poor guy landed at my airport with his brakes on and he didn't get away so lucky.

 

 

He probably wasn't using FULL FLAPS

[scottfromiowa]

Flying a Corsair..."Poor Guy" not what I was thinking...

[Marauder]

Flying a Corsair..."Poor Guy" not what I was thinking...

Ah come on Scott! You know "poor" is a relative term

[jetdriven]

A hammer and a dolly that will bang right out

[flyboy]

Uh oh, I see the great "brake tap or not tap" for wheel spin debate coming

 

I tap the brakes before gear retraction. After the gear retraction, then there is flap retraction. ( Sorry, I couldn't resist  ) Oh, and the step is retracted prior to engine start, just after the last passenger steps up on the wing. This gives me something to do while waiting for passengers to load.

[DonMuncy]

Lood has a good point.

Naturally it isn't something I would know anything about, as I have never bounced a landing, but I have a friend who bounces one occasionally. Then I, er he gets that vibration. But it doesn't do it on takeoff. Is it possible that at take off, the wheels are spinning at 60 knots or so, but when landing, a bounce will spin them faster than that. Or is there some other explanation.

[BigTex]

I too have a friend that had a similar experience... He explained it as feeling like when landing you just touched down on railroad tracks.  His first thought was that he carried a little too much speed and/or might of not been on his toes and had some breaks applied.  He only experienced this once.