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Nose heavy issues

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Chopndrag

Well-Known Member
Joined
May 8, 2014
Messages
489
Location
Crystalriver,Fl USA
Went up today and actually got some seat time in. Even at cruise rpm I had to hold back pressure on the stick. Plane was a flying plane when I got it could it be me weighing less then the previous pilot to make that much difference? Also speed was maybe 100mph at around 3300rpm.
 
what kind of trim system does it have? On 994SP, its very possible to put the HS back together and get the trim system out of rig so that even with the trim wheel run as far up as it will go, you still have to hold aft stick all the time.

It took me a couple of tries to finally get it rigged correctly.
 
what kind of trim system does it have? On 994SP, its very possible to put the HS back together and get the trim system out of rig so that even with the trim wheel run as far up as it will go, you still have to hold aft stick all the time.

It took me a couple of tries to finally get it rigged correctly.
No trim at all. I have the aeroconversion trim system I am putting in. Looked at the car from and it is severely nose heavy.
 
How does it land? Do you feel like you have enough stick to flare for landing?

Maybe you should just go ahead and do a whole new weight and balance, just to be sure. If your CG is within the prescribed limits then, maybe your horizontal stab incidence is incorrect? That's the only thing I can think of.
 
Doing weight and balance tomorrow. I'm about 30lbs lighter then the previous owner. I had just enough stick to flare for landing left . Hopefully only weight and balance and fly again. I found the w&b sheet from a couple years ago it was at 5.52 ... nose heavy already. Doing the trim system while I at it.
 
Went up today and actually got some seat time in. Even at cruise rpm I had to hold back pressure on the stick. Plane was a flying plane when I got it could it be me weighing less then the previous pilot to make that much difference? Also speed was maybe 100mph at around 3300rpm.
The first thing I would do is re-weigh the airplane. Make sure it falls within the envelope empty with min. fuel with pilot, then fully loaded. Then shim stabilizer for neutral stick at cruise speed. I have a cockpit controlled trim tab on my elevator. I have also seen some clever bungee controlled trim systems too. Bungees offer less complexity and less chance of flutter.
 
If the aircraft is out of balance and you're holding a lot of back pressure on the stick you're inducing a lot of extra drag and hurting performance. Let us know what you learn from the weight and balance check.
 
Adjusting the horizontal stabilizer will reduce the back pressure on the stick, but it won't correct a nose heavy condition. It just makes the stab do the work the elevator was doing. And that drag hurts performance.
 
Adjusting the horizontal stabilizer will reduce the back pressure on the stick, but it won't correct a nose heavy condition. It just makes the stab do the work the elevator was doing. And that drag hurts performance.
That's the thing I don't knownif it is technically nose heavy. I know for a fact the stab is almost at the top which would make it feel nose heavy too
 
Try leveling the fuselage. Put the tail wheel on something to make the upper longeron level using a spirit level or a welder's angle finder. Then measure the angle of incidence of the horizontal stab and tell us what that is.

Also, did you do the new weight and balance? WHere's your empty CG?
 
Empty cg is 5.95 .... was a flying plane before I got it. Only thing I can think of is I'm about 30lbs lighter and seeing the stab so high up makes me wonder of that isn't giving it nose down attitude.
 
Frankly empty weight doesn't mean crap. The LOADED weight AND balance need to be between the prescribed limits. The CG limits are 8 to 16" aft of the leading edge. The maximum weight limit varies but is from 950 to 1150. If the LOADED W&B are in the box, then adjust the stab. If the loaded weight isn't in the box, you add ballast to get it in the box. The Sonerai flies fine at the forward end of the CG if set up right, but you have to check the CG. If there have been changes to the airplane, then reweigh it and establish a new W&B chart. If you are flying without knowing where your loaded CG is then stop and figure that out.
 
Mine is 1150 4 year old cg from previous owner. Working on cg now but either the diagram from the manual is wrong or it's really nose heavy. It has ballast in the back . Previous owner flew all the time in it. Said at 3200rpm it was level. It drops the nose on me at 3200rpm really bad.
 
Mine is 1150 4 year old cg from previous owner. Working on cg now but either the diagram from the manual is wrong or it's really nose heavy. It has ballast in the back . Previous owner flew all the time in it. Said at 3200rpm it was level. It drops the nose on me at 3200rpm really bad.

@chopndrag , what have you got for an engine? Do you have a starter and full size battery?

Given all you've said, I'd definitely re-do the official weight and balance docs. And, I'd definitely go over that horizontal stab incidence. Maybe time to get some research done on what your horizontal stab incidence should be per plans. Somewhere in the plans there's got to be some numbers.
 
@chopndrag , what have you got for an engine? Do you have a starter and full size battery?

Given all you've said, I'd definitely re-do the official weight and balance docs. And, I'd definitely go over that horizontal stab incidence. Maybe time to get some research done on what your horizontal stab incidence should be per plans. Somewhere in the plans there's got to be some numbers.
I have a 2180 with starter and odyssey 680 that sits behind me. I'm really leaning towards the horizontal stab being out of wack. It's up really high in the front which would make down elevator. Ran the numbers for cg and something isn't adding up from the sonerai plans. The cg from a couple years ago has empty being about 5.6 inches empty . I had somewhat the same problem with a previous plane and it was the stab being set wrong along with pitch in the prop. I can't see how a couple years the cg would go out that bad unless it's just weight differences of me and the previous owner. He weighed about 30lbs more then I do . What does everyone else have for empty cg ? Per the manual at empty my plane is right on target.
 
Just me talking.... I would not fly a newly purchased experimental without doing my own weight and balance. It will take about an hour even if you have to remeasure all of the moments. You can do it with a bathroom scale, level, tape measure, pencil, paper, and calculator. W&B is simple arithmetic. If you know how to use spreadsheets, it is even easier. Don't trust your life to someone else's crayon!

As for the horizontal stab....the leading edge should be spaced off the top cross brace with washers. Most Sonerai owners find that they need quite a few washers to get the leading edge down where they need it for neutral trim at cruise speeds. However, there is no point in adjusting the HS trim if the CG is not where you want it.

If you really trust the last EW CG, you could simply add the moments for fuel and pilot to calculate your loaded CG. If your loaded CG is between 8" and 16" from takeoff to landing you are within limits. Just start adding washers until the stick is trimmed.

Yes, a lighter pilot would move the CG forward.
 
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