Weighing M20J

[jetdriven]

6 hours ago, PT20J said:

I’ve never weighed one. But it must be possible to do it accurately using the procedure in the manual since the factory had to do it in the first place.

I’ve read that they actually don’t weigh every plane.  They weigh every (5th, or 12th etc) and apply that to the ones in between.  This is before equipment is added.  So the original number is an estimate.  

[RLCarter]

1 hour ago, jetdriven said:

I’ve read that they actually don’t weigh every plane.  They weigh every (5th, or 12th etc) and apply that to the ones in between.  This is before equipment is added.  So the original number is an estimate.  

I've heard/read that as well. I know the weight on my Nose wheel is 2lbs lighter than the Factory's W&B sheet, and It have a light weight starter and alternator conversions 

Edited June 25, 2020 by RLCarter

[JimB]

I'm not sure I understand this discussion of weighing an aircraft is less accurate than attempting to calculate 50 years worth of the equipment additions/deletions... Aircraft get weighed all the time and with the proper equipment and understanding it's accurate. From a 747 to a 150. However, I do think the procedure in the Mooney manual is over complicated. There is no reason to do all that. For the F, G and J models, simply drop a plumb bob off the reference point measure center of the nose gear and the main gear axles and adjust by the 5" to get your distance from reference datum. I calculated it following the manual and calculated it the more conventional way and the result was exactly the same. 

I just finished a bunch of changes to my F and removed every ounce of extra wire and crap left there after every mod over the last 50 years. After I weighed her the CG was within 1/4" of the factory and she actually gained a few lbs over the years. I was hoping to gain a little UL but that didn't surprise me since people tend to be a little liberal when applying weight changes (hence the reason a proper W/B isn't a bad thing). 

[mooniac15u]

3 hours ago, jetdriven said:

I’ve read that they actually don’t weigh every plane.  They weigh every (5th, or 12th etc) and apply that to the ones in between.  This is before equipment is added.  So the original number is an estimate.  

So, at recent production rates Mooney probably hasn't weighed a plane since 2017.

Edited June 25, 2020 by mooniac15u

[cliffy]

Don't believe everything yous see!

When I weighed my 64 D the first time I found a @90 lb error in the arithmetic on the original  W&B sheet from the factory!

Many years of calculated W&Bs had been done using those original figures with no one even thinking of going back and checking the numbers on that one and each subsequent one for accuracy. Some A&Ps literally can't add 2 and 2. 

And if you reweigh your airplane be aware there is a very subtle difference in "Empty Weight" between CAR-3 airplanes and Pt 23 airplanes. Many times it gets screwed up. Could mean a difference of 15 lbs or more  :-) for every T/O