Hi all,
I am looking for some input on track & balance as it comes up on our pride and joy!
My personal experience is a lot of R-44, some R-22 and some Bell-47 and 206.
On the EC120 I am basically new.
Of course we always go with the EC-manual, but anyone who does track & balance knows, that there is still a lot of "Black Arts"/"Witchcraft"/"Magic Hands" involved!
So here it comes:
Until now I always extracted from the manual, that T&B would be done in the following sequence:
a) Balance on ground or hover
b) Track on ground or hover - adjust with pitchlinks
c) Track in flight - adjust with tabs/readjust pitchlinks for hover
d) Check balance again
e) Start all over if you have to...
Now I am curious what you have to say about the EC120 or any EC for that matter:
a) and b) are pretty much the same, but at c) there is no adjusting for Track, but for vibration.
I understand, that sometimes you might get a smoother ship if the blades do not track perfectly (wake aerodynamics I guess...), but what I do not understand is, why one would not at least try to get all the blades into line before diverging again (if necessary...).
Matter in case: On blade is obviously climbing a little at max cruise, but instead calling for some trimtab action to bring it down in line, the vibration graph is asking to push the blade UP even further (with the trimtab)!!
I understand that not always everything looks "logic" at first sight, but this gets me,
Manual says to visualize the track and do trimtab adjusments according to the graph. Now all the blades are dead-on on the ground and in hover and are still within tolerance in flight, but of course one always wants to go as smooth as possible.
"Logic" tells me to "pull" the blade down with the trimtab - manual says "push it up". If it where for the pitchlinks, no problem I just try it out, but those trimtabs definitely have a limited "bending"-lifetime. I don't want to bend them the wrong way just for a trial....
Any "oldtimers" (nothing to do with age actually,
) out there with some hardcore experience in this matter?
I guess any A-Star, Squirrel, Ecurielle, etc. will do as the ships have basically the same rotor!
Thanks,
3top
