Randy,

 

Some of us would say that the pitch harmony is in tune with B-sharp or B-flat.

 

B-careful about change - every control system is made of matched elements and a change to a component may have undesirable consequences on its other parts.

 

1. It is typical of the 300 series aircraft although some elements are improvements over the 200 series. Also, the Legacy has better control harmony. 

 

2. (a) Ailerons - Leave them alone.  Note that they are much larger in the Legacy to cause less displacement to have a greater effect.  You cannot multiply force by modifying the linkage - just make it friction free.  Besides, it depends on how fast you want the roll - i.e. it doesn't take much stick pressure to slowly roll the airplane.  I use a servo controlled spring system for whole aileron trim and it is very sensitive.  The next time you fly try to get into a 60 degree bank in less than 2 seconds and then try to take ten seconds to do it - the forces are quite different.

 

(b) Elevator - Yup, sensitive to the touch (uh, sensitive and touchy).  Remember to let got of the stick when you sneeze or be prepared for an aerobatic maneuver called the achooit.  The original elevator bell crank provided for an arm of 4 inches and a girth-challenged individual determined that pitch stick movement was limited when it reached his belt buckle - so, he shortened the bell crank arm to 3 inches (just drilled another hole) - this resulted in reducing the throw 25% and increasing the force applied to the stick by 25%.  The unintended consequence was that the crucifix-shaped trim system depended on friction and springs that were inadequate and required good arm strength to overcome the new holding friction force in order to change trim - trim that ran out of full control with the original weak springs when the elevator was amply deflected.  Enter the Reichel geared trim wheel and it much heftier springs.  Now she's sensitive, but a bit sedated.  Full fist for roll, dainty fingers for pitch - and keep your arm on your leg for stability.  I am not sure about the bob weight (that is, I am not sure whether 200 series had one or not), but its purpose in the 300 series was to add stick forces as Gs increased so that sensitivity was reduced in hi-G maneuvers (hah!).  Enter a 60 degree steep turn without changing pitch trim and hold it thru 360 degrees - note how much bicep is required.  Now the aircraft is responsive, not sensitive. Note also that the ailerons are back to neutral and require very little force to change the bank angle while you are hauling back on the stick.  See, responsive with reverse harmonimity. BTW, I have the 3 inch bell crank, Rechel wheel and stiff springs.  Now the problem is that the walnut wheel changes size because of humidity trends and that changes the friction relative to its movement.  Arrrrggghhhh.......

 

3. Don't mess with the ailerons.

 

4. I have the small tail and, by adjusting the pitch trim spring location until all trim requirements are met, I generally do not run out of elevator or trim.  From single pilot, low fuel to gross weight, the elevator retainss its authority.  Note that my aircraft favors forward CG.  I always use full flaps (depending on x-wind) upon landing, requiring quite a bit of nose up trim.  At race speeds (for me, a little in excess of 204 KIAS), I do run out of full nose down trim, but I like that as I am not likely to run into the ground while holding a bit of forward stick at those speeds - that is, should I momentarily lose concentration or become fixated with some gadget in the panel.

 

Finally, a suggestion to tone down pitch sensitivity - Use an ace bandage wrapped around your stick forearm and thigh - then continue on up so as to also bind the upper arm to your chest.  Don't breathe deeply as this may upset the pitch and heaven forbid that you should be afflicted with restless leg syndrome (ah, that malady can lead to the Humpty-Dumpty maneuver).

 

Blue skies and stable flight,

 

Grayhawk

 

PS Hey dude, leave harmonization to the Beach Boys.

 

PPS Just how long is your bell crank, eh?

 

To: All LNC2 drivers and anyone else that wants to weigh in on the subject,

 Subject: Stick force harmony (or stick movement vs. control surface movement) between pitch and roll

 My Lancair 360 (N360DE), which I have flown now for 450 hours, has an characteristic that I would like some input on from all you well-informed and intelligent LML readers and contributors.

 The characteristic is: Very sensitive pitch axis that is not harmonized with the roll axis.

 I have gotten used to the difference and frankly don't plan on changing anything about it unless someone out there has a good suggestion.

I have some questions:

1.       Is this typical of the LNC2?

2.       What kinds of things should I be concerned about in considering any changes to the linkage of the system?

3.       Has anyone made any changes and what were the results?

4.       Does anyone out there have any experience with using full pitch deflection - in any portion of flight?  I imagine it might be needed in landing, full flaps, lower speeds - but I have not seen it.

 It seems to me the way to make an increase in aileron sensitivity is to change the mechanical linkage geometry to effectively make the control surface move more degrees of rotation per degree of stick movement.  This would (and could) be done but the resultant would be the stick not getting full deflection (as compared to now) in the cockpit when the aileron was at full deflection.  This might not be a bad thing because right now the stick has to be jammed up against one or the other of your thighs in order to get the aileron to full deflection.

 Ideally I would like to have less sensitivity in pitch, resulting in more stick deflection for the same pitch results as now - and less total stick deflection in roll, which should result in more roll sensitivity.

 For clarification purposes - my horizontal stab and elevator are a one-off design of Chuck Brenner.  Chuck was involved with part of the construction of this project prior to my involvement with it.

 Randy Hartman

Cell (319) 360-9775