Cessna 120 - Std Empty Weight 1092 / CG 18.08 - Normal?!

[maverick_fa]

Hello,
I'm looking to buy a Cessna 120 1946.

When I was looking at the paperwork I found that the std empty weight is 1092 pound with a CG @ 18.08.

Std Empty Weight of a 120 should be 785 pounds IAW AOPA webstise (see below link):
link: https://www.aopa.org/go-fly/aircraft-an ... na-120-140

The Empty Weight CG range should be 12.3 to 14.7 IAW "Aircraft_Type_Certificates_Cessna_120_1302111219.pdf".
I have been building a custom W&B in excel based on the file mention previously & the 120/140 POH (Cessna 120 Operation Manual.pdf).

I was trying to do the Math to figured out why the AC is 300 pounds heavier than what it supposed to be with the following estimation:

AC Retrofit & Upgrade
1. C-85 swapped for an o-200 +10 pounds
2. Vaccuum Pump, Alternator +20 pounds
3. Avionics (6 packs, XPDR, Radio, GPS) +15 pounds
4. Metal Wing +50 pounds
5. Paint +5 pounds

- Sum = approx. 100 pounds

The current empty weight is at 1092 pounds. There is a 200 pounds added somewhere IMO.

Did I do something wrong or I don't understand something?

Please let me know.

Thanks,
Mat

[6643]

The weight is pretty high. It's not unusual to find one in the 950-1000 lb range, but 1092 is extreme. Also, the CG is dangerously far aft. It's beyond the allowable limit for a loaded plane.

Mine is pretty porky at 985 lbs but the cg is only at 14.3 (and it's a 140)

So, either someone made some mistakes weighing and calculating, or there's about 150 lbs of contraband in the tail cone.

[maverick_fa]

Thanks for the info.

I was reading Budd Davisson's PIREP about the 120/140 & he also claimed 950 to 1000 pounds for a 120 with some retrofit/upgrade.
The 120 is already 75 lighter without the flaps/electrical motors.

I hope the AME screw up the calculations. It's a very beautiful 120.

[6643]

Wing flaps are only +6 lbs. The electrical system is significant, but most 120's have been upgraded. Today's interiors are generally heavier, too, and the original finish was bare aluminum and linen wings finished through silver.

I'd guess you're looking for about (at least) a 150 lb mistake in the weight and I wouldn't lay down any money until you understand what's going on.

[maverick_fa]

Is it possible the the A&P (AME in Canada) forgot to subtract the weight of the bar to lift the tail when he did the W&B 8 years ago...
A 150 pounds bar to lift the tail.

That or the cocaine in the tail when the AC was imported from Wichita...

Thanks for the clarification!

[VIP620]

the dec 46 120 that i have, is a non-electric and in 2002 it weigh 823 lb, cg 14.3 f and 16.98 aft and if one installed a battery/ lite weigh starter that would be roughly 26.6 lb more

[8342]

Sounds like it needs to be put on a set of scales and verified.

Rick

[6643]

I didn't want to say anything until I verified the numbers, but, if the empty CG is at 18" then there is no way to load the plane and get the CG to move forward. The arm for the seats is 19.5 and fuel 23, so it will only move farther aft.

[maverick_fa]

You are right... everything bring the CG aft except for the oil (this isn't much)

120 Empty Weight CG Range (Landplane) should be between 12.3 & 14.7 IAW FAA TCDS (REF 1st post)
I was expecting to found a 120 in the 900 to 950 pounds range (a lot of retrofit/upgrade)

Even if a battery, elt, bigger tailwheel are added... there is no way the Empty Weight CG will be at 18.08.

I hope the guys that has been weighted the 120 in 2013 did forget to subtract anything that was added on the scale to lift the tail & the AC was leveled when this exercise was performed.
The current owner has flown approx 150 hours on it since that time & he did some spins. He told me that he never got any problem with his 120.

Very strange.

[6643]

The current owner has flown approx 150 hours on it since that time & he did some spins.

What can I say? That's like agreeing to play Russian roulette after being told all 6 chambers are loaded...