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Guess your weight.

S

StewartB

On the "Other Airplane" topic, a couple of other guys also stated they liked their 180/185's. TJ says his '53 180 weighs #1496, 85Mike just says "light" 185. My 180, according to Cessna, is the identical weight as 85Mike's '67 185, at #1565. I'm here to tell you, my plane, which isn't full of a bunch of flashy radio gear, is closer to #1800. Next week, I'm having a new weight and balance done, on certified scales, with actual equipment. I will report the calculated (old) empty weight, and the new (accurate) empty weight. Has anyone else done a real W&B on anything other than a new rebuild? How did the actual weight compare to calculated? I've avoided this because I really didn't want to know, but my mechanic says it's time. How much DOES your plane weigh?
SB
 
Pool??

Stewart,

We should have a pool on your empty weight. $5.00 per guess, winner is the closest without going over. Winner gets half and half goes to Supercub.org.

Roger

More brilliant ideas from the "Wooster Head"
 
Weights

I think Cessna only ever weighed one plane. After that they just calculated everything they added or took off. Stewart if you have Rod weigh it, I'll bet your late model 180 with the big engine conversion and polyurathane paint job weighs around 1900 lbs if it weighs an ounce. Some of these later radioed up 185's are up closer to 2000 lbs. Crash
 
weight

Sometime back around 93-94, the OAS boys out of Boise decided that all the cubs in Alaska that contracted with the Gov. had to be weighed. They showed up with their fancy digital load-cell scales, and you could tell from their attitude that they knew they were going to catch you with your pants down. You had to be hiding something. I'd never weighed my cub and figured I was dead in the water, going to be shot at dawn. They put it on the scales and it weighed 20lbs. less than the calculated W&B. I about dropped dead from relief. They were disappointed, how could this bush-rat be legal.
 
I actually weighed my 185 after throwing away the un-used black boxes in my panel. Read DME etc. Panel now has KY97, KX170 with GS and KI208, Skyforce GPS which I love! (Cub has one also) KT 76A TXP. I also added a fuel flow in the re-work. Weighs 1789 lbs with the gas drained and 10 qts oil in the engine. My plane is about half bare with accent paint. Note I didn't say polished!!
85Mike
 
85mike,

Can you post a picture of the Skyforce in both the cub and 185? Been looking at them, but was concerned about the size, etc.

Thanks,
Carlon
 
Crash,
You may be right. As I said, I'll tell everyone what it does weigh when I find out. Remember it carries the Fluidyne hydraulic pump and fluid reservoir all year, it's on 29" Bushwheels and an XP 14" tailwheel, has a big motor, and 86" 3-blade prop. None of those things are light. (Keep in mind that even if it's #1900, I still have #1300 useful load, and can fly it at 170-175 mph off of 1000' easily.)

As some of us make the argument for stock Cub wings vs. extended, you are buying into the compromise that a little higher wing loading is a good thing for way we use our planes. Criticizing the weight of a Cessna is easy, but I'd rather fly a heavy Cessna in the turbulence. The only trade-off is short field performance, and if you can get it into your field, good enough, right? Same argument as a stock wing cub. Sometimes, wing loading is your friend.
SB
 
weight

Diggler: Drop a plumb bob down from the datum, mark on the hangar floor, measure back to the axle on the tailwheel. The bigger tailwheel forks/tires change the scott station.
 
weight

stewartb: keep an eye on that XP tailwheel. The top bearing shoulder on the lower fork cracks, if you do any rough/off-airport work. Everyone that I have checked is cracked. Two that I know of have departed the aircraft, one stayed attached by a steering cable and punched a bunch of holes in the elevator.
 
nanook,
Thanks for the heads-up. I'll switch back to the stock 3400 for Burl's tail ski, so I'll get the opportunity to look. Getting cold up there yet? 18* at my house this AM. Nice northern lights show, though. Should be again tonight.
SB
 
I bought a '56 180 and stripped it down beyond belief. No radio's, no Gyro's, No interior, one comm and a handheld GPS. The weight and balance from the factory in 1956 said 1614.5 and mine came in stripped down at 1615.5.

Last year I bought a '54 170B and stripped it down to absurd levels and the original factory W&B said 1205 lbs. and when I got done it weighed 1265 lbs without any gyro's or interior. I removed the big bench seat (35lbs) and installed a single cessna jumpseat (10 lbs).

How do these numbers add up.

Kelly
 
My cub weighs 1186 off of Rod's scales. The setup is: 160hp, stock wings, belly tank ,31" Bushwheels, one comm.

The 185 weighs 1815 off of certified scales. The setup is 300hp, Bush STOL (like a Horton), Old heavy IFR radios, firewall battery, ext baggage, 26" Bushwheels, 10" Scott tail-wheel.

Good topic

Kris
 
Diggler

The Tailpost should be at 245" (185") the Piper TCDS shows the 3200 Tailwheel at 260" (200"). I just reviewed a Weight and Balance from a Float install that Wipaire just did on a PA-18 and that one had the Tailwheel at 264" (204"), so I assume it was the longer spring. Others I have seen use the 200" (260") number.

Frank
 
Scales

I question some of the weighing techniques used to weigh airplanes. Rod has a set of certified scales that are three piece and all connected together into a single display unit. He has a portable crane that he uses to lilft the tail up to flight attitude and has one scale on it and one under each tire. He said you can't just weigh each tire. There is a differential that has to be computed in. I am not clear on this but his weights always come up higher then most guys expect, but are most likely true and accurate. Crash
 
Ok this is where I have trouble. If you took your truck and parked it on a truck scale, it would way X. If you lifted the back of the truck without taking from the weight, it would still weight X.

If you get all three points of an aircraft on the scale at once, it should not matter if the tail is up or not. Now if you are trying to determine CG, that is a different story, but weight is weight, upside down, nose high, or nose in the dirt.

sj
 
So the only thing that happens when you lift the tail up, is more weight gets put on the mains? And if you weigh the tail at different lengths from the front, the wieght on the mains and tail change? Sounds right, but would the numbers change that much?
 
Steve,
The guy we use up here does a CG for the individual airplane, as equipped. Crash did it on his 14. It sounds like Kris did it on both his planes. That's the essence of my original post. Calculated and real weight aren't always the same. The CG envelope will be the most interesting comparison. I always hear guys talk about how much their planes weigh. Very few really know, or know where the weight is.

Kris, how did the certified numbers compare to your calculated numbers?
SB
 
Wilbur is right if you raise the tail you get more weight on the mains and vice versa...the total weight will be the same either way...BUT the reason you weigh with the airplane level is to be able to calculate the Empty Weight CG. Your basically turning the airplane into a balance scale.

Example: With the airplane level you weight it and find the Mains weigh 560# each for a total of 1120#, and you find the tail weighs 60#. The total weight is 1180#.

The Mains on the Cub are at a 60" arm, so 60"Armx1120#=69440 Moment. The Tail is at 260" Arm, so 260"Armx60#=15600 Moment. Add the weights together for a total of 1180#, and the Moments together for a total of 85040. Now divide the Total Moment by the Total weight 85040/1180=72.07". You now have your Empty Weight CG, 72" or 12" aft of the Leading Edge of the Wing. Without the Airplane being level, your just fooling yourself as to where your Empty Weight CG is. BTW I it should not make any difference where you weigh the tail (tailpost or Tailwheel) as long as you can measure the Arm.

Frank
 
Diggler

The Tailpost "should" be at 185", so measure back from there to see where you come out. With the Airplane level you should be able to drop a plumb bob down from the wing leading edge (the center of the main gear axle should be 2" aft of this point when level) mark the floor, then do the some at the tail and measure the distance, if you want the exact distance.

Like I said above it really doesn't matter where as long as you know the correct distance from the leading edge. BTW if anyone does the math the Main gear is actually at 62.25", not the 60" Piper used.

Frank
 
diggler said:
The arm for the Scott 3200 is listed as +200 inches. I was wondering if that was to the tire or the center weight of the 3200? I think just about everybody weighs from the tail wheel? I think the factory weighed at the tail post?
Turn the tail sideways to the centerline, then you know you are weighing from the center of the Scott. Still like to know who the genious at Piper was that decided not to use the datum for their Weight and Balance computations.
 
StewartB,

The 185 was 9 lbs. heavier than the calculated weight from 12 years prior.
the CG was much closer to the front of the envelope than previously. This stumped me until I remembered the firewall battery.

Kris
 
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