Light aircraft flips on French Island 21/01/23.

[facthunter]

IF you just got a beep from the stall warning as the wheels touched you had it right.  That's for fairly stable wind conditions. If it's gusty you have to  carry a bit more speed  and have a bit of power to give more control.. Wheelbarrowing is a fairly accurate way to  describe when the nosewheel contacts first.  Avoid it.  Nev

[kgwilson]

1 hour ago, Yenn said:

So the correct way to land is nose wheel aircraft is to keep applying back pressure after touch down to keep the nose wheel off. Whatever happened to applying increasing back pressure to hold the nose wheel off before touch down?

The nosewheel should always touch down after the mains. Keeping the weight off after touchdown reduces stress from undulations in the runway. Many nosewheels have no suspension so shocks have to be absorbed by the tyre and leg.

[Thruster88]

My RV has a heavy Hartzell CS prop and with just me and full fuel the CG is at the forward limit. RV6 has a small tail. The farm strip is bare earth and I nearly always have a look at the touch down marks after landing. Always land with the stick well or fully back however the nose will always touch within 5 metres of the mains. Cant keep it off and I don't try to when taking off, I like a positive rotation at the correct speed, departure stalls suck big time.

 

The nose leg on the RV is plenty strong enough, it is the same type as the other legs on nosewheel and tail wheel RVs. If it can support the weight in the hangar it can support the weight going 50-60knots down the runway.

 

So why do they bend? 

 

I think it may be some form of violent shimmy.  We have a long spring with a heavy piece (nosewheel, fork and spat) on the end. Imagine the aircraft lands in a crab or the free castoring nose wheel is at a slight angle at touch down, it flicks to one side and then on the next touch it binds slightly and drives the nose leg sideways, repeat a few times and the leg bends.

 

A few years ago there was one at Narromine with the leg bent out the side, it got me thinking why is it so.

 

The one at William Creek had an after market reinforcement,  it did not say what type in the ATSB report. 

 

What can we do.

Correct nosewheel tyre pressure, Van's recommended 25-35, they say less is better,  I use 25psi.

Correct breakout force on the nose leg, 10kg for my aircraft. 

No side slips on final, we want that free castoring tyre to be straight at touch down.

Land it like you  are doing a wheel landing in a tail wheel aircraft, smooth, straight,  no crab touch and a slight pin, we don't want that free castoring nose wheel skipping about.

 

 

 

Edited January 27, 2023 by Thruster88

[kgwilson]

I have heard many pilots complain about castoring nosewheel shimmy but I have never had the problem. For my aircraft the castor bolt should be tightened so that when lifted of the ground it takes 1.5 to 3kgs of pressure at the rear of the tyre to move it. That is reasonably stiff and keeps it straight while flying & no amount of sideslip will move it. There is no shimmy on the ground at any speed and turns with the rudder are fine although there is always some lag so unless a touch of brake is used a turn needs to be anticipated.

 

Recommended tyre pressure is the same as the RV 25-35psi & like T88 I use 25psi. mains are 35PSI as per Matco/Airhawk recommendations.

Edited January 27, 2023 by kgwilson

[facthunter]

You'll never taxi crosswind without constant braking.  The Fokker F-27 was originally  designed with a Castering nosewheel. THAT didn't last long. How does the rudder work/help when taxiing downwind? 

[Thruster88]

I have never experienced nosewheel shimmy in the RV, the break out force is 10kg at the axle. After a few hours you forget about the castoring nosewheel, it just works. 

[facthunter]

My last Post didn't mention shimmying. ALL planes want to weather cock into wind. The downwind brake is all you have to stop it with any castoring nosewheel. Nev