It was mentioned that "Short direct cables will only work if the wind is straight on your nose and you are not producing any torque; otherwise it won’t."
Unfortunately this statement is completely wrong or has many errors and please allow me to explain why. As we all know, landings are easy, as you have no engine torque issues, and high airspeed, so cross wind limits to land I would say are 20 knots plus depending on how in practise you are. But take off limits are different. On Take off, Jabiru and 0-200 engines torque wants to turn the aircraft to the left and you have to apply right rudder to keep straight. Therefore if the crosswind is coming from the right, that helps weathercock the aircraft against the torque and you could take off easily in a 25 knot crosswind. A crosswind from the left adds to the engine torque and I would limit a left hand cross wind to 15 knots or less if you have limited length and need full power immediately, as you simply don't have enough rudder authority when the tail lifts at about 30 knots. Below 30 knots the tail wheel will be on the ground and steering the aircraft to the right or doing its best, depending if on grass ,gravel, sand or tarmac, along with the rudder position. If you put a spring on the tailwheel steering, it doesn't aid steering much if at all and you can't keep it straight even with full rudder. It just goes where ever the aircraft wants to take itself, as the rudder doesn't have enough authority. SO short cables and no springs improves the crosswind take off performance of KR2 taildragging aircraft 'without any doubt' and who wants an aircraft you can only fly in calm nil wind conditions with the wind straight down the runway? The confusion that most pilots have is that most aircraft like cubs have a rudder big enough to work at about 5 knots and the tail you can get off the ground very quickly, so yes, tail springs work with them because the rudder is so strong. The KR2 rudder is small and only really adds authority to direction above 25 to 30 knots, below that you will be relying on the tail wheel steering. Having springs in it won't help! And once the tail wheel is off the ground, who cares what system you have as its off the ground and won't do anything anyway. In strong blustery conditions you don't three point an aircraft, well not a KR2. If you tried to slow the plane up to three point in strong blustery conditions, you'll right the plane off. Its best to wheel it on with speed, speed is your friend and aids control, allows for sudden wind gradients, you can see where you are going with the lower attitude, the rudder works fine, the differential brakes will help, you try to keep the tail wheel up off the ground with forward elevator until the aircraft speed is insufficient and it lowers, the moment you feel it drop, just easy up and centre the rudder because the tail wheel steering will take over and be direct as long as you don't have springs. The further example given was as follows. : "You are approaching to land and have a three knot crosswind. You have one wing down into the wind and enough rudder to hold the nose straight down the runway. As you slow down it takes more rudder to keep it straight. Everything looks fantastic, it’s going to be a great landing right up until the point that hard wired tail wheel touches the ground. In that instant the tail is going with that tail wheel that is cocked over at 25 degrees. Guess where the nose is going? You got it; every which way that you don’t want it to go." One would say that "Its not going to be a great landing if you touch down tail wheel first? I've never landed my KR with the tail wheel anywhere near the ground. You keep it in the air as long as you can, when it finally settles at 25 knots, as I mentioned just relax your feet. 25 knots is slow enough that nothing is going to happen and you have direct steering anyway, no springs messing it up. Please watch the following videos if anyone has doubt of what is being said. The wind is plus 20 knots and blustery between the trees with a strong wind gradient, but with increased speed, not reduced speed to try to three point the aircraft, the pilot has full control, aces the touchdown, and can keep the aircraft straight with rudder and brakes until the tail settles at 15 knots ground speed with the 15 plus knots head and crosswind, the pilot even has time to wave to his friends and make them laugh. https://www.youtube.com/watch?v=RSJXKZhHkfQ Also this video shows landing on Tarmac, short field approach on rough Grass, landing on Gravel in Greenland with 15knots plus from the right, Tarmac at StMary where the pilot was requested to expedite and approached at 100knots and touched down at 80 knots, you'll not do be able to do that trying to three point and on long runways you wheel it along with that tail off the ground until dropping the power just before the turn off, so again tail wheel steering is irelivant, as the tail wheel is not on the ground. Finally at Oshkosh, just missing the yellow dot touch down point. You can see or hear when the tail wheel touches down on all occasions and there is no sudden change in direction as mentioned in the previous comments. I still see no reason to three point KR2's. As to what tail wheel steering to have. Surely it is obvious. https://www.youtube.com/watch?v=9FJuTyf2sJc CH But with slack in the cables, the tail wheel will snap straight in line with the direction of travel and make you look like a master tail wheel pilot. For springs to work you have to experiment a lot to get the correct tension that will both allow the tail wheel to follow the direction of travel and be powerful enough to steer you during taxi at slow speeds. The strength of the springs is related to the mass aft of center of gravity and the arm of the controls. It’s an experimental aircraft though and you have to decide just how much you want to experiment. I am a CFI who teaches tail wheel. I would fly a KR with springs for the tail wheel but only in dead calm winds. My recommendation though is to go with what has been proven to work. Victor Taylor ________________________________ -Please see LIST RULES and KRnet info at http://www.krnet.org/info.html -Change list delivery options at https://list.krnet.org/list/krnet.list.krnet.org/ Affinity List Info Board -Search recent KRnet Archives at https://list.krnet.org/empathy/list/krnet.list.krnet.org/ -Search John Bouyea's decades of archive at https://www.mail-archive.com/krnet@list.krnet.org/
