CG Adjustments Part 1

I’m happy to report that I’ve lost enough weight that it is time to adjust the CG (Center of Gravity) on my Six Chuter P3 Lite Powered Parachute.   It was adjusted for max pilot weight.  I am nowhere near that weight.  Also, when I take off I noticed that the carriage swings on the pitch axis (nose to tail) on lift off.  Kind of like a teeter-totter effect.

So after checking the manual I adjusted the lift tubes for my current weight + 10 lbs.  The lift tubes are what the parachute risers are connected to.  If you extend them, you move the CG forward, if you retract them, you move the CG rearward; the lighter the pilot, the more forward you have to adjust the CG.  Six Chuter made this fairly easy by pre-drilling holes in the lift tubes through which you insert a pin.  The lift tubes are designed in a telescoping manner and you extend or reduce them to the proper measurement as called out in the manual for pilot weight.  Then insert a locking pin through the hole and the CG has been set.  The adjustment I made to the lift tubes ended up being extended them such that the pin was moved two holes in each tube.

This morning I drove out to New Jerusalem and gave it a test flight.  What I found was that the cart lifted off rear wheels first and the nose wheel was rolling on the ground.  Not by much but enough that I noticed it.  I immediately cut the power and landed again.  I had extended the tubes by too much.  Apparently I had underestimated the weight of all the gear I fly with, it’s obviously more than 10 lbs worth.

After landing I was still rolling and decided to try something.  I was about 1 quarter of the way down the runway and slowly pulled off to the extreme right of the runway, keeping my parachute centered overhead.  Then I slowly fed in left rudder bar and the chute started to sway to the left.  I entered an easy left turn and the chute returned overhead while I was still turning.  I steepened the turn and fed in more left rudder bar until I had done a 180 turn.  I relaxed the rudder input and as the parachute started to veer right I straightened out the turn and the chute returned overhead.  I was able to drive all the way back to my trailer like this.

Long time PPC guys will say “So what?  I do that all the time!!”

I say, “Good for you PPC guys!”  This was my first time being able to do a 180 on the runway and taxi back.  It felt pretty good to me.

After getting back to the trailer and putting the chute away I set about RE-adjusting the CG.  I shortened the riser tubes by one hole which SHOULD put the CG back about where I wanted it to be.  So the net effect will be that I only lengthened the tubes by 1 hole.  I’ll give it a test flight tomorrow morning and report back.

Here’s a short video from my POV…


2 thoughts on “CG Adjustments Part 1

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