If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#31
|
|||
|
|||
Leading Turns with Rudder - Revisited
On Tue, 12 Aug 2008 20:09:25 GMT, Eric Greenwell
wrote: bagmaker wrote: - I don't have the full context from the quote above, and while I am normally loathe to contradict Langewiesche, I must report I have successfully produced turns with just the rudder in gliders. Give it a try, and you will find you can produce an adequate turn, because the yawing causes the dihedral to bank the glider in the desired direction. I suggest you give it a try at or near the stall... I've not done it myself, but I've read about how attempting a coordinated turn at or near stall can cause an "over the top" spin entry when the out-of-turn aileron is deflected downward and stalls the outer wing tip. In any case, my experience (and the text books) indicates that an attempt to turn at or near a stall risks entering into a spin, even with "proper" use of the controls. The pilot should speed up before attempting the turn, coordinated or not. This reminds me of another frequently repeated statement: "you won't spin if you keep the yaw string centered." Besides my amazing ability to turn a glider with just the rudder, I also have the ability to enter a spin from a coordinated turn! I've done it in our club's Blanik and my current glider, and I think it works on most gliders. Here's my secret: *enter a coordinated, shallow (say, about 10 degree bank) turn *reduce the airspeed slowly while keeping the yaw string straight *at some point, the inner wing will drop, and the spin begins (it might be spiral dive with some gliders) *recover in the usual fashion when desired (I prefer to do it sooner than later) Of course, the glider's attitude is nose high, along with other warning signs that the pilot is not doing things right. Still, I wonder how many pilots unintentionally flew too slowly, but thought they were safe because the yaw string was centered. The understanding of just what a centered yaw string indicates is something I have always struggled with. After some thought experiments, and some flying experiments too, I have come to my own realization that I must never assume that a centered yaw string indicates anything about the angle of attack occuring on the left and right wings. In a coordinated turn, that is, a turn during which the yaw string is centered, the angle of attack of the inside and outside wings is not the same. the AOA of the inside (on the turn side) wing is greater than the AOA of the outside wing and will stall before the outside wing, and if the pilot allows this process to further develop the glider will enter a spin.. We all know this, but I have to keep reminding myself. The centered yaw string is not an indication of equal AOA of the two wings. It only indicates the direction of air flow right where the yaw string is. I think I better write this on a postit and stick it to my panel! |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Leading Turns With Rudder | sisu1a | Soaring | 89 | October 25th 08 12:30 AM |
Visual coordination of turns revisited | Mxsmanic | Piloting | 50 | February 14th 07 03:57 AM |
Is rudder required for coordinated turns? | Mxsmanic | Piloting | 41 | September 24th 06 06:40 PM |
procedure turns revisited | [email protected] | Instrument Flight Rules | 37 | June 20th 06 03:39 AM |
Compass turns revisited | Bob Gardner | Instrument Flight Rules | 41 | April 10th 05 03:01 PM |