|
|
I would like to congratulate the Cafe Foundation for writing another terrific in-depth article, which was in the recent March 2003 issue of Sport Aviation. They are a wonderful organization.
On pages 43 and 44, the author casually mentions two observations about trim on the stick--two things that have been discussed on this site, and which are significant safety issues.
Firstly, Mr. Stephens mentions four buttons on the top of the stick that operate rudder and elevator trim. Then he mentions, "the elevator trim worked well, but was sensitive, and adjusting the pitch trim needed just a tap of the button in the desired direction". He then says,
(paraphrased), " (items resting) on top of the (stick and) trim buttons (caused) sudden and excessive trim inputs".
Well, duh, doesn't anyone at the factory read this fine website? This problem was first mentioned by me in the very earliest years of the site, and I have brought the problem up several times since.
What would there be in the cockpit that might come to rest on top of the stick that would input excessive trim inputs? Well, in my case, it was the palm of my hand...
The problem occured during departure roll on my first flight, and was exacerbated by the fact that too much voltage to the trim motors made the movement of the control surfaces tremendously fast.
Well, duh, tremendously fast, as in the recent Cafe case. Again, it is apparent that no one has been listening--I have written repeatedly about installing pots inline to slow down the control motor movement by lowering the voltage. Yet the factory supplies a pilot a plane with 15 minutes of familiarization, hands over the keys, and the pilot later discovers an anomaly that should have been corrected years ago...
I am surprised that Mr. Stephens reported the problem in such mild terms. Of course, he had no idea that this problem was one of 6 or more years standing, and that it had been repeatedly mentioned in this forum. Perhaps if he had known that, he would not have been so mild in it's reporting...
Anyway, my point is this--all you newbies out there, be warned that if you put the palm of your hand over the top of certain brands of sticks, it is possible to run the trim to the stops. And, if you have not put pots inline, they will run to the stops in a second or two! I also suggest that you do not put your rudder trim on the sticks--put it on the instrument panel with an indicating meter, or some day you may find yourself going down the flyway sideways and wonder why....
Safe flying to you all.
David Jones
|
|