Wait and Balance

rudymantel · Post by **rudymantel** » Sun Jun 15, 2003 2:25 am

Eric, my compliments on your excellent article on weighing your airplane in current Flypaper ! I enjoyed it.
Wen I bought my plane I had it weighed- it came out surprisingly close to the calculated number from many years ago, but I'm glad I did it.
Rudy

zero.one.victor · Post by **zero.one.victor** » Sun Jun 15, 2003 5:23 am

Thanks,Rudy. I still haven't got mine in the mail yet--I think my mailman musta hijacked it!
Since I wrote the article,I've trimmed about 30 pounds off the airplane's weight--it's down to about 1310. I replaced the bench rear seat with a single 185 jump seat,and I removed the vacuum system & instruments as well as a marker-beacon receiver & antenna.

Eric

rudymantel · Post by **rudymantel** » Sun Jun 15, 2003 12:23 pm

Eric, that weight loss is impressive. With your cool climate that 170 must perform nicely. Here in south Florida at sea level the day starts witha density altitude of 1500' and continues climbing.
I know it's far from your home to Wilmington- any chance you'll be there ?
Rudy

zero.one.victor · Post by **zero.one.victor** » Sun Jun 15, 2003 2:33 pm

Nope--might make Tehachapi,though.

Eric

Dave Clark · Post by **Dave Clark** » Tue Jun 17, 2003 1:19 pm

Eric

I just got the 170 News and really enjoyed your article. Nice job. My calculated weight after all the mods came in at 1344 with Javelin tank but no rear seat which I didn't think was too bad. I also didn't think it was very credible so I'm real reluctant to weigh the airplane, prove it wrong, and have less legal useful load.

zero.one.victor · Post by **zero.one.victor** » Wed Jun 18, 2003 5:23 am

"Don't ask,don't tell" is my motto on a lot of this stuff.....
Thanks for not beating me up on the forum for lying about the free gas Sunday..............

Eric

Collin Gyenes · Post by **Collin Gyenes** » Sat Jun 21, 2003 3:23 pm

Hi,

I had my plane weighed at my annual (6/18/03) at Twiss Air Service at Astoria, OR. The plane has a nav/com, Apollo GPS, Oil filter, Std rear seat (heavy), Xponder, two gyros, Wheel paints, NO gas, 5 qts of Oil. The weight was 1353 lbs.

'52 170

Post by **GAHorn** » Sun Jun 22, 2003 1:21 am

After my airplane was totally stripped down, and restored, with only about 12 lbs of radios it came out (with wheel fairings) to weigh 1303.2 . The more interesting thing to me is the arm/moment which is stated in my wt/bal to be 42.63 and 55578. How about others listing their arm/moment figs.?

mit · Post by **mit** » Sun Jun 22, 2003 1:44 am

here is mine
WT CG
Wheels 1363 38.21
skis 1405 37.43
Floats 1519 38.21

i will have to look up the arm and mom.

zero.one.victor · Post by **zero.one.victor** » Sun Jun 22, 2003 5:29 am

Since I wrote the "Wait & Balance" article,I installed a single 185 rear jump seat and removed the vacuum system & gyro's. Currently,my 170 weighs 1,310 pounds,moment 50,361, for a CG of 38.44". That's including oil & unusable fuel. I wouldn't mind a little more weight loss but am reluctant to start stripping out the upholstery,carpet,headliner,etc.
Just for reference,the original factory W&B sheet sez it weighed 1,244, moment 45,896,for a CG of 36.9" with the same fuel/oil status. I noticed that the actual scale readings were not included,they probably weighed the first one & just used the same figures for all the rest.
The airplane was also weighed after an extensive post-wreck rebuild in 1960. That sheet sez it weighed 1.312, moment 50,646, for a CG of 38.6".
It musta really been a hot-rod in the original configuration,IF that 1,244 weight was for real! But that's a big IF!

Eric

zero.one.victor · Post by **zero.one.victor** » Sun Jun 22, 2003 5:36 am

George,your airplane's weight is very believable,but your CG is way aft of where I woulda thought it was. You might want to check the W&B calculations,they mighta got the arm(s) wrong or screwed up the math. I would think the CG would be somewhere between 37 & 39".

Eric

Post by **GAHorn** » Mon Jun 23, 2003 4:03 am

Yeah, Eric, I troubled over that a long time before I realized that the graph in the Owner's Manual doesn't deal with ARM, it deals in INDEX units, which are derived by wt X ARM divided by 1000. This works out in my airplane to have an empty weight Index unit of 55.6 which is actually in the MIDDLE of the envelope.

lowNslow · Post by **lowNslow** » Tue Jun 24, 2003 1:08 am

Moment 50550
Arm 38"

(pretty close to Eric's)