Larry Mednick
Forum Replies Created
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Hi Vassili, good to see you here. Yeah, Fly Com also went up 15% and BRS went up 30% overnight!
things are getting really expensive really fast… -
Hi Pete, a few factors… Having at least 20 PSI in the 21″ tires will reduce the contact patch size, the larger the contact patch with softer tires, the faster the tire will tend to spool up. The chirp we often hear is the time it takes for the tire to go from 0-landing speed. The longer the chirp, the longer the tire takes to accelerate which drastically reduces the aft force swinging the carriage backwards. In the grass it’s even longer. Adding power at touch down will typically increase the time it takes to put the weight onto the tires which again will slow the spool up of the tires. Smaller and or lighter tires may not slow the spool up, but will have less affect when they do.
Next is where is the bar at point of the mains touching down. If the bar is “pinned” forward you can expect the nose to drop uncontrolled regardless of tire size. So holding a flare off too long with a trike can be detrimental to lowering the nose down nicely. However, most often the nose comes down abruptly BUT the control bar is not all of the way out as the nose wheel touches. This is pilot error in my opinion, since there was control available, but unused. The most common 2 reasons for not using this range of AOA is not leaning forward and not being able to reach well. The second trick is to have the control bar in forward motion as the mains touch. This will allow the control bar to CONTINUE forward as the pilot seat is literally yanked back away from the controls. So holding the controls steady in one spot as the mains touch means that when the pilot seat gets pulled back, the pilot is actually pulling the control bar back without moving the bar. When the bar is traveling forward it allows the bar to keep moving forward at that critical moment. If you watch a no handed landing you will see the control bar appear to lunge forward when the mains make contact without the pilot’s input. See the 0:47 mark on video https://youtu.be/pxWXCbB3pHU
Lastly, if you can get the bar all the way out at the same moment the nose wheel touches the ground, that is a text book landing in my opinion and the nose should USUALLY touch soft and hopefully not bounce. This can be done with or without power.
Remember once the mains are down and the nose wheel is still in the air and the bar isn’t pinned all the way out, the tire’s moment of inertia, contact patch size and landing surface no longer affect the nose being lowered to the ground. And again I increase AOA to lower the nose down softly, although the popular way seems to be to decrease the AOA to do so which I do not personally subscribe to.
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The “nose slam” phenomenon is very real. Without an elevator to control pitch attitude at touchdown like an airplane, the carriage swings back as the wheels touch, and the more rotating mass and the larger diameter they are, the more affect they will have. This is why we don’t use the 22” tires on the REVOLT on hard surfaces. The 600s and 700s aren’t horrible when you go to something like a Michelin (we have tried them all) but those tires are only 15-17”. By the time you go to a 21” tire, you don’t want more than 4 ply and you don’t want tubes because the moment of inertia is so much larger.
I ran into a fellow that had 29” tires on his trike and I asked him if he ever landed on hard surface with it. He said no. I told him to be very careful if he ever does.
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Hey Pete, sorry for the trouble, so the actual browser needs to be copied and pasted and not the share link from YouTube. That should make it work.
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You should get an email. I guess this reply will be a good test.
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Ok, question for the group: If you wanted an electric soaring trike that could really thermal, would you be concerned with how many feet it could climb or how long if could fly? For example if it could climb 7500 feet per charge or fly for 1 hour per charge. And How would you fly something with a <200 FPM sink? Low level flying? Exploring? pattern flying? climb to cloud base or altitude and soar? All of the above? And would this be an only trike or a 2nd trike for you.
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At Oshkosh I was able to confirm eye witnesses said he climbed out to 300’ and spiraled it in. I imagined it went about like that before finding out.
We had a beautiful memorial for Sam at Oshkosh where his Grand daughter read a beautiful Eulogy about Sam.
He will be missed
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We don’t have private messaging on here YET…
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So when the wind gust comes from the right for example, the relative wind you were flying in which is going straight over both leading edges and hitting the front of the carriage now shifts to from the right. If you are going 50 MPH and get hit with a 90 degree, 50 MPH gust from the right, the relative wind will shift temporarily to a 45 coming from the right. If we imagine your leading edge is at 45 degrees (90 degree nose angle, for example purpose , yours is 135 degrees) the trike is now in a slip and 100% of the relative wind is pushing on your right leading edge and 0% is hitting the left leading edge. The wing now will coordinate itself so it is flying straight into the wind again. When the gust goes away, the process repeats itself again and the trike coordinates again.
So if you felt that when it turned sideways your trike was flying sideways through the air, I can see that raising alarm, but the fact that when it turned sideways your were now flying straight into the relative wind with a crab angle to the ground. The trike after the initial yaw/heading change was as happy as it was a second before the gust. And as mentioned, your ground speed may have slowed down, but should have continued in the same ground track. So maybe less concern now with more understanding that your trike simply coordinated itself and was flying straight through the air when you were eyeballing that BRS handle.
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Not to nit pick but a blast from the right will turn you right. So must have been a gust from the left that turned you left. Typically there is no roll upset when you get a horizontal blast, just a temporary heading change. if you are touching down, add power and time the “swing back” with the touch down. Otherwise just ignore it because your flight track should remain unaffected.
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Paul Hamilton has similar field elevation and mountains. But you don’t need 100 HP. Something like a REV X has similar power to weight ratio.
Here is us taking off in Stevensville MT flying at 12,500’ https://youtu.be/PEq4DGu7zM0https://youtu.be/PEq4DGu7zM0
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Hi Monte, unfortunately 5000’ elevation is pushing it unless you weight 150 or under and 6,000 feet in the summer is a deal breaker for the REV ultralight. We have over 5 years worth of Rotax 582s which can reach over 15,000 feet. The REV X would definitely be the choice for your application between the. 2 of them. Many of the much smaller lighter trikes can operate from those elevations on the same 36-38 HP motors such as the ATF or the ANT.
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Roger, trim speed and touchdown speed do not affect the height of the nose wheel when the mains touch. That is controlled by the geometry of the carriage. It is possible to swing the carriage which can cause the nose wheel to rise higher because of the swing with over controls during the flare.
In bowling there are many ways to get a strike, but only pro bowlers can get 10 in a row and all use a similar technique. Want to put the nose wheel down gently and consistently there is only one way to do it. Want to get consistent strikes, there is only one way to do it. And like bowling, if you change your technique don’t expect instant results. But with practice, the sky is the limit and total control over the nose wheel is possible in light enough. conditions.
Bar pinned as the nose wheel touches is like the spin on a bowling ball…
Here is the technique again. It’s a transferable skill with consistent results for a 400 hour pilot like Wayne.Wayne’s New REVO
https://youtu.be/UKQHPdQVegEWayne’s New REVO
https://youtu.be/UKQHPdQVegE -
Swing? Did it yaw or did the carriage swing or both? Did the carriage bank at all
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wind sheer can be completely horizontal and in many cases is.