Weight and balance

Weight and balance

Postby Trevor Gfeller » Wed May 17, 2017 3:06 pm

Can anyone share their W&B info? The literature with my plane shows a much smaller cg window fore and aft when compared to the ICS poh I purchased. I have a 63 PA 24-250.

For the life of me I can't get my cg anywhere close to the aft limits and am often too far forward. I'm 245# but even playing around with the pilot weight being 150# it's slightly better. I'm working these with just the mains full, no aux fuel filled.

My paperwork with the plane shows 88 cg forward and 91.8 cg aft at max gross. Ics poh is 86 and 93
Trevor Gfeller
 
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Re: Weight and balance

Postby N3322G » Wed May 17, 2017 9:05 pm

Trevor - our experience is that re-weighed CG is often not correct. Last time we audited, they were 3 different errors in CG calculations post-re-weigh. If you really want to know, re-weigh as service manual specified while you are there watching to insure the process is correctly followed for your aircraft. Prior-owner, Mom, once had a re-weigh change the CG by an entire inch. She said, cow manure and had it done again. There was 0.1 in change.

This may or may not impact your situation.

FYI. Most aircraft have gained weight since they left factory. Heavier interior fabric, heavier insulation etc.
Pat

Patricia Jayne (Pat) Keefer ICS 08899
PA-39 #10 Texas
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Re: Weight and balance

Postby Trevor Gfeller » Wed May 17, 2017 9:42 pm

There was a re weigh with a close to current load out which is what I'm inputting for empty cg, but the limits are confusing me. I'll post a picture of my sheet when I can, but the picture shows the load envelope with the limits as far forward as 86 inches and back to 93 on gross which matches the ics poh I bought. But the literature on the same page says 86 and 91.x which is much more restrictive.

Hopefully that makes sense
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Re: Weight and balance

Postby Michael Bryant » Thu May 18, 2017 3:28 am

If I understand correctly, you are looking for the CG range. It is listed in the TDCS (Type Data Certificate Sheet).

But here is the data (there is a graph in the TDCS but it looses format when being copied/pasted:

PA 24-250 Center of Gravity S/N 24-1, 24-103 through 24-2298, except 24-2003:
(C.G.) range
(+87.7) to (+93.0) at 2800 lb.
(+82.5) to (+93.0) at 2400 lb.
(+80.5) to (+93.0) at 1900 lb.

S/N 24-2003, 24-2299 through 24-3687:
(+86.0) to (+93.0) at 2900 lb.
(+82.5) to (+93.0) at 2600 lb.
(+80.5) to (+93.0) at 2000 lb.
Straight line variation between points given.
Moment due to retracting of landing gear (1266 in. -lb.)

Michael
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Re: Weight and balance

Postby Trevor Gfeller » Sat May 20, 2017 9:31 pm

Thank you very much, that's comforting seeing the document. I've talked more with people using water ballast in the baggage compartment to help landing flare.
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