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Shudder/Vibration after Tkof


Roscoe
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Hi all, can anyone explain this brief shudder at about 150ft on tkof which dissipates quickly?

 

Could it be out of balance tyres ?

 

Appreciate comments thanks Guys

 

 

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Hi all, can anyone explain this brief shudder at about 150ft on tkof which dissipates quickly?Could it be out of balance tyres ?

Appreciate comments thanks Guys

Bound to be out of balance tyres. Apply the brake. If this doesn't fix it could be the front tyre.

 

Test by lifting the front in the hanger and notice if the wheel wants to settle in the same place at the bottom.

 

There is a recent post about this and remedies

 

Phil

 

By the way, regards your gps installation query in another post, I made the bracket on photo from a part from the kit supplied with my unit.

 

The very great advantage of this positioning is that you don't look down when using and does not interfere with visibility.

 

My panel has the gps cutout, but not good for the above reasons.

 

Cheers

 

Phil.

 

 

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Phil

 

Bound to be out of balance tyres. Apply the brake. If this doesn't fix it could be the front tyre.Test by lifting the front in the hanger and notice if the wheel wants to settle in the same place at the bottom.

There is a recent post about this and remedies

 

Phil

 

By the way, regards your gps installation query in another post, I made the bracket on photo from a part from the kit supplied with my unit.

 

The very great advantage of this positioning is that you don't look down when using and does not interfere with visibility.

 

My panel has the gps cutout, but not good for the above reasons.

 

Cheers

 

Phil thanks I now have a RAM Mount with suction cup which works great!

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There is a story about how factory testing in the early days showed shuddering at about 100 knots. They thought it might be flutter and they beefed up the elevator hinges. In fact it was a wheel starting to spin with the slipstream being enough to do this at 100 knots.

 

The advice about using the brake is correct, but do it gently as it is apparently possible to do damage.. I guess that all the rotational kinetic energy in the spinning wheels has to be absorbed somehow, so you don't want a sudden grab.

 

 

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Well you probably could do 100 knots at 150 ft in a 6 cylinder Jabiru, but the story was about how the wheel or wheels STARTED to spin at 100 knots and how they worried about it being flutter. I guess the bit sticking out below a spat has a turning effect from the slipstream and this effect increases with speed.

 

... Bruce

 

 

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Guest Fresno Jab
Hi all, can anyone explain this brief shudder at about 150ft on tkof which dissipates quickly?Could it be out of balance tyres ?

Appreciate comments thanks Guys

Not sure, I have the same issue on occasion...can feel wheel spin up on rudder pedals. Maybe main tires scrub from landing gear decompression on take off?

 

 

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Thanks.Others have suggested its the tyres spinning after liftoff which can be fixed by applying brakes briefly.

 

Not sure, I have the same issue on occasion...can feel wheel spin up on rudder pedals. Maybe main tires scrub from landing gear decompression on take off?[/QUO

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Obviously if touching the brakes get rid of it it is the mains.

 

I have found a slight shimmy from the nose wheel about the time referred to when the nose is left on the ground too long. I find picking the nose wheel off the ground a couple of inches early in the take off roll and letting it fly off when ready elimates this (being mindful that you have no directional control until the rudder starts flying)

 

 

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dont forget, some aircraft fitted with wheel spats, can have their wheels constantly rotate in flight, even my Savannah nosewheel never stops turning from take off until after i land and park the aircraft

 

 

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dont forget, some aircraft fitted with wheel spats, can have their wheels constantly rotate in flight, even my Savannah nosewheel never stops turning from take off until after i land and park the aircraft

Yep, my spatted Sonex does it continuously, I can set the brake lever behind the flap lever to apply park brake inflight.

 

(Flap lever won't operate if I forget downwind check, and I rarely perform flapless approach but there is always the potential of course to land park brake on.. )

 

 

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Murphy's law. I wouldn't set a brake on in flight, as a principle.

 

We ALL do a pre landing brakes check don't we? but.....

 

When you take off, you know the brakes are off. When you are landing you need to know they are off. Nev

 

 

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