Ross, I've been preaching about not using plastic brake lines all the way to the brakes for at least 15 years now. You were lucky. Your brakes weren't hot enough to create a fire. Others haven't been so lucky.
I noted in your video that the nosewheel was cocked off sideways before touchdown. Must have got a good sideways bump on rotation to get it in that position, but I would think it's pretty likely having it cocked off like that probably precipitated the shimmy you experienced. I would think that if your nose gear has a centering spring, that situation should be avoidable. Some of you nosedragger pilots that own the Diehl gear can comment here. Doesn't that gear have a centering spring? Does it pull the nosewheel all the way back straight? -Jeff Scott Los Alamos, NM ----- Original Message ----- From: Ross Evans Sent: Monday, April 27, 2009 7:50 AM Subject: MY KR Shimmy Problem Hi Kr Guys, I have had problems with emailing KR net if one of you could please post this message up for the benefit of the group I would be most appreciative. I was flying down to Natfly when I landed at Moree I was taxing around on on the long strip and I blew the clear brake line tube (most KR's use on the Clevelands). The tube blew about 30mm from the caliper there is a slight bend at this point where the line then runs up the back of the Diel leg. I have since found out that this type of tube can not tolerate heat and it's operating and burst pressure decreases. I am currently looking at hydraulic tube that has an operating pressure of 10 000 PSI and a working temp of 350 degress celsius (it is a bit of overkill for non boosted brakes but murphy's law is you will always blow a line at an airshow or when your mates are watching!!! I must admit I was using the toe breaks to have effecting steering on the ground at low speed than I normally would. (Normally I only have to taxi about 70 metres from the hangar to the strip and the taxiway is half way down the strip). The nose wheel felt stiff when I was pushing the plane back to the tiedown area. I removed the nose fork for inspection and found that the fork was quite stiff. I had only done about 15 landings since the 100 hourly in which I disasembled the leg and cleaned the assembly. I did notice quite a bit of grass and soil around the assembly. I used some Inox to lubricate the the nose assembly smart thinking? I conducted a test flight on the plane after fixing the brake line with no shimmy on asphalt. I rechecked the nose leg friction which was good after the test flight. I then took off for Narromine. My hangar buddy filmed my landing when the shimmy occured. The belivue washer must have settled I could not feel any end float on the pivot bolt but my lubrication abilities are definately good as the assembley felt like a bearing was installed. I cleaned all the lubricant out installed another washer and replaced all the noseleg bolts just in case of fatique. I have done another 8 landings since on asphalt, grass and gravel and there is no sign of shimmy. My question to Krnet is has anyone had a fork break from fatique. I am going to have the fork crack tested so that I don't have a bad day in the future. I was speaking to a variety of people at the event and many said that on Cessna 180's that you never lubricate the tailwheel pivot as you will get shimmy some aircraft worse than others. I was on the phone to Paul Smith who has said there is a grease with friction properties. I have some photo's of my kr at www.lvflyingclub.org My Kr is 912 powered and has a sensenich 60 inch ground adjustable prop. I cruise at 120 knots. cheers Ross Evans _______________________________________ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to [email protected] please see other KRnet info at http://www.krnet.org/info.html ____________________________________________________________ Save $10 on Flowers and Gifts! Shop now at www.ftd.com/16714 http://thirdpartyoffers.juno.com/TGL2141/fc/Dh4GRr5bIdw2XxFz8jTZttaGOyaDkhBOnvpKq0iMDZVu6yI5iti4MSfIE3u/
