Weight and Balance Error?

[hnorber]

My friend owns a Mooney MSE and is preparing to take an IFR checkride in the plane.  He's now dug out the W/B data, and it seems to show that the empty weight CG Arm is 62.63", which, when combined with his empty weight of 1918 pounds, gives him an Empty Weight Moment of approx 120153.   Although he has a useful load of 982 pounds - there's literally NO loading configuration that puts his CG anywhere close to within limits with these numbers (with an empty weight momoent of 120153 - his CG is way, way aft of limits, and even a theoretical 500lb pilot won't bring it forward enough).   So - it seems that my friend is either miscalculating his W&B (I don't think so) OR... there's a historical error in the WB history that resulted in the Empty Weight Moment of 120153 being recorded in his POH.     Does anyone have any thoughts on whether 63" seems like an impossible CG Arm for an empty MSE and/or what can be done to fix this in short order (otherwise he will need to reschedule his checkride!).

 

Thanks,

Howard

 

[carusoam]

Mooneys have a tendency of being pretty far forward in the envelope when only the front seats are filled...

The evidence of this, comes from the use of all of the trim in the landing configuration, during slow flight...

If Something was added to the back of the plane and it is really giving a back of the envelope WnB, the plane would be trying to lift it's nose early during the T/O run....

It is easy to become familiar with the WnB of the plane.  The logs and POH(modern plane) are the source of the data. Check the equipment list to see what is really there against the actual plane.

Some people have posted their numbers before... after doing the math, I found some confusing details, like sub totals, that caused things to be counted accidently more than once....

PP thoughts on WnB, not a CFI...

Best regards,

-a-

[RLCarter]

32 minutes ago, hnorber said:

My friend owns a Mooney MSE and is preparing to take an IFR checkride in the plane.  He's now dug out the W/B data, and it seems to show that the empty weight CG Arm is 62.63", which, when combined with his empty weight of 1918 pounds, gives him an Empty Weight Moment of approx 120153.   Although he has a useful load of 982 pounds - there's literally NO loading configuration that puts his CG anywhere close to within limits with these numbers (with an empty weight momoent of 120153 - his CG is way, way aft of limits, and even a theoretical 500lb pilot won't bring it forward enough).   So - it seems that my friend is either miscalculating his W&B (I don't think so) OR... there's a historical error in the WB history that resulted in the Empty Weight Moment of 120153 being recorded in his POH.     Does anyone have any thoughts on whether 63" seems like an impossible CG Arm for an empty MSE and/or what can be done to fix this in short order (otherwise he will need to reschedule his checkride!).

 

Thanks,

Howard

 

I would have your friend re-check his math 62.63 x 1918 = 120124.34 not 120153 so there is one mistake

[hnorber]

Yeah - I rounded a bit here, but I think the point is that, with these figures, it'd be literally impossible to fly inside the envelope.  We're digging into the logs - it looks like there may have been a miss-conversion from cm to inches after the plane returned to the US following a period when it was registered in Germany.

 

[Yetti]

my F empty weight arm is 1717   44.37

60s is somewhere between the front and rear passengers

[kortopates]

There has to be a major error here. Typical mid bodies are in the low to mid 40" cg. Go through the superceded W&B and Iam sure you'll find the issue.
Pretty crazy if it's been being flown since importing without a valid W&B, so glad you're helping the owner/pilot out.


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[ArtVandelay]

I just went through all my weight and balance entries and put them in a spreadsheet. there were about a dozen errors but they mostly cancel out and I was accurate to within in a pound and 1/4 inch, my CG is about 46. I have almost a 100 entries.

[RLCarter]

He can also weigh the aircraft and get a new W&B, kind of a pain but he'll know exactly what it is. 

[hnorber]

Thanks for the replies.  We’re going through the entries in the POH today.  I’ll update if we find the error.

[jaylw314]

My M20J has a empty weight of 1867 lbs and an arm of 47" for an empty moment of 87.8k

The aft CG limit should be 50.2" or something like that, so something is definitely wrong.

Incidentally, the fuel tanks are at an arm of 48", so changes in fuel load should barely change the CG. 

[gsxrpilot]

Compared to the F33A I used to fly, a Mooney can't hardly be put out of CG. The F33A had to tanker around fuel just to keep it in CG. And god forbid you flew to far, or the wind wasn't right, you'd use too much fuel and then couldn't hardly land because of CG issues.

The Mooney, we just load it, fuel it, fly it... rinse and repeat.

[steingar]

I think I’ve said this before, but the only W&B guidance I could find in the POH of my ‘62 C was a statement that I shouldn’t put the big guys in the back. Should make checkrides that much easier.

[bradp]

I recently found an error where a previous avionics shop used cm instead of inches.  It wasn’t a significant error since they were avionics (light) and not too far from the arm - but I would recommend either going through the logs and recalculating and double checking each entry -or- just getting the plane reweighed. Either way is going to require a signature in the logs from an AP - especially for purposes of an upcoming checkride.