PA 12 Gross Weight Increase

[jrb]

I have done a bunch of searching and reading. I was wondering what folks current feelings are on the gross weight increase on a PA 12.
These are the facts as I understand them.

It is accomplished during rebuild on new or old fuselage.
2 STC's available: one from Crosswind/Charlie Center and the other from Borer. Both have the same requirements.
Standard Gross is 1750.
Gross increase is 1935.
Gross weight increase allows for an additional 185#
Weight of additional tubing is unknown to me. Rumor has it at 10 to 30 pounds in additional tubes and welds.
Taking into the account the 185 minus the 10-30 in tubing gives a net somewhere around 155-175 of useful gross weight increase.
All of the tubing/weight is aft of the pilot.


Does anybody have additional facts? Opinions? To do or not to do? First hand experience/knowledge? Would you do it again? No brainer?

Trying to make a decision on a utility 12 with most of the mods. including 0320, borer, flaps, 18 gear, 18 feathers, bushwheels (31's), etc. Seems most twelves like this weigh 1250ish empty, including the gross weight increase

Thanks for any input.

 

[nanook]

I'm flying one now with the gross wt increase. I'm on the firefighting flight line now and not near the log books. This 12 has a Univair fuselage (Dakota), with float fittings and double seaplane doors, 150 hp, Borer, 18 gear, flaps, tail. Tires are AWB 31" & baby bush wheel. Has the lightweight starter & oil cooler. Dodge tanks and Dakota ribs. EW is 1170lbs.

 

[jrb]

Good job, that sounds lighter than most from what I have read. I am familiar with a 1264 empty. Trying to keep it light, but not fanatical.

 

[nanook]

I weighed one last year, had the original fuselage with the 18 flaps & tail. This 12 still had the original gear and had the 150hp, Borer, lt wt alternator & starter, 31" bushwheels, Gar-Aero TW. Dodge tanks and original piper ribs. 1230lbs with the gross wt kit.

 

[MT12]

After flying my 12 for about 14 years it was due for a recover/recondition about 5 years ago. It now has flaps, 0-320, 18 tail feathers, heavy original battery, generator and starter; 12 gear with 850's, a fishing pole tube, medium baggage. It weighed in at 1149. But do the math: gross of 1750 less empty weight 1149, less full fuel 36x6=216, less a 180# pilot on a good day and it leaves me a 'real' usable load of 205, ie not much.

I had so much fun and learned so much on that recover I bought a project and am building another 12, this one came with 18 heavy duty 3" gear, 24 gallon Dakota cub tanks, flaps, and came with a very questionable fuselage. I ended up buying a shiny new Univair fuselage (its like a work of art) and I had them put on all of the mods that were already in the books. Which included flaps, extended baggage which mandated pa-18 torque tube and elevator cable reroute, I got a pair of floats for it-so I added float fittings. I plan on a 160hp 0-320 for it with borer prop.

Because of the 205# usable in my flying cub, and the bigger tanks and float potential for the project cub I opted for the gross weight increase, if for no other reason than to be able to fly legally with full fuel on floats. And with a 5 1/2 hour round trip to Johnson Creek this weekend I wish I would have had the bigger tanks in my flying plane. My goal for this cub is also 1150 empty but bet is will be closer to 1175, going with a odyssey battery and a light weight starter. I am just finishing up the fuselage now, and about to start on the 'pilot seat forward' expensive part of the project and looking at it I would definitely do the gross weight increase again. I probably would not do the bottom extended baggage but so far happy with my other decisions.

Borer and Charlie Center worked together on this STC and both filed it as I understand it, so its the same STC from either party. There are a couple of gussets near the sky light as well to add. I think 20# of added steel is about right. I'm not very worried about all of the weight being behind the pilot, my flying cub has the ELT and 4# of lead in the tail to offset the 0-320 weight and it flies like a dream. I have the elt in the tail already of the project but will forgo the lead. Univair was great to deal with, as I recall there was little or no charge for installing the gross weight increase beyond the steel since they were building the fuselage from scratch anyway.

If you are buying new or seriously modifying an old fuselage do look into Charlie Center's STC to square up the bottom rear part of the door. Sure makes access to the back seat and rear storage easier.

and remember this opinion is worth exactly what you paid for it....

 

[Scooter7779h]

Do the GW increase for sure. Why not increase legal useful. Had it on both of my 12s. Have owned them combined 37 years and over 4000 in the 12s

Sent from my SM-G920V using Tapatalk

 

[DENNY]

I have a cub but if I had a 12 and wanted to work it I would do the GW upgrade. It really adds a lot of strength to the fuselage. The big door is another mod I would do. I would also do the square wing and big flap mod. It is a lot of work and money to do it all but if you want to haul a load it is the way to go. If you just fly empty than a stock 12 is fine. There are ways to save weight even for a working 12 just pay attention to the little things.
DENNY

 

[PIPER J5.5]

+1 gross weight increase. It's worth the work.

 

[jrb]

Thanks for the input