Coeur d'Alene, ID
Well I can't help you with that one. I don't have a copy of the LEW on hand. Those were my two I had at the same time, and a comparision was requested. If you just want to argue...go find a different pig.
PA12 Flight Characteristics Vs. PA18
- Thread starter Steve Pierce
- Start date
Well I can't help you with that one. I don't have a copy of the LEW on hand. Those were my two I had at the same time, and a comparision was requested. If you just want to argue...go find a different pig.
skywagon8a
MEMBER
SE Mass MA6
I'm sorry Lisa, I'm not trying to argue only expressing amazement at such an unheard of light weight. I do know that manufacturers were well known to use marketing numbers on their W&B sheets. You did say you didn't know the weight of the floats, so I supplied you with that information.
I've got enough (for me, not very much comparably) time in a -12 and an -18 to note the following:
- A modded -12 will run out of nose up if flown solo (or at least with my phat a** flying it solo) without some strategic placement of survival gear and supplies.
- An un-modded -12 has a noticeably lighter feel on the stick than a modded -12
- The -18 does have AOA benefits over the -12
- I've been in 3 different -18's and 4 (including mine) different -12's. Other than one of the -12's that was essentially unairworthy, all of the airplanes could fly better than I could drive them.
- I can fly my -12 to it's limit about 1 in every 6-7 flights. When I get to the point that the aircraft is the limiting factor, I'd probably look for a light -18, but I'm not sure I'll ever make it to the point where the critical path to ideal low and slow runs through the aircraft instead of through the driver.
- A modded -12 will run out of nose up if flown solo (or at least with my phat a** flying it solo) without some strategic placement of survival gear and supplies.
- An un-modded -12 has a noticeably lighter feel on the stick than a modded -12
- The -18 does have AOA benefits over the -12
- I've been in 3 different -18's and 4 (including mine) different -12's. Other than one of the -12's that was essentially unairworthy, all of the airplanes could fly better than I could drive them.
- I can fly my -12 to it's limit about 1 in every 6-7 flights. When I get to the point that the aircraft is the limiting factor, I'd probably look for a light -18, but I'm not sure I'll ever make it to the point where the critical path to ideal low and slow runs through the aircraft instead of through the driver.
RaisedByWolves
FRIEND
Tx
Maybe they used the same scales piper used from the factory.
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Very interesting. I didn't know any -12s had factory installed flaps. Sounds like a fun airplane. Have you flown a modified -12 with a short mount?
pcj_5189
MEMBER
Northern MN
Didn't know they made them either until I ran into a guy with a bone stock -12 with factory flaps.
skywagon8a
MEMBER
SE Mass MA6
They are listed on the type certificate A-780, but only as an aftermarket approval.
"*602. Flap installation installed in accordance with Mainair, Inc. (formerly Marden +14 lbs. (+39)Airways, Inc.), Waterville, Maine, PA-12 Flap Kit No. 1000-M and Installation Instructions dated January 22, 1949"
"Approval for the installation of all items of equipment listed herein has been obtained by the aircraft manufacturer except thoseitems preceded by an asterisk (*). The asterisk denotes that approval has been obtained by someone other than the aircraftmanufacturer. An item marked with an asterisk may not have been manufactured under a FAA monitored or approved qualitycontrol system, and therefore conformity must be determined if the item is not identified by a Form ACA-186, FAA-PMA, orother evidence of FAA production approval."
If they were installed "at the factory" I suspect the completed plane was taken "across the field" after production for the modification prior to delivery. It would be interesting to see the original paper work on these two airplanes to answer the question.
pcj_5189
MEMBER
Northern MN
I saw the plane when I looked at another -12 the guy had for sale and he stated that the one with flaps was one of "a few" that came with factory flaps. I didn't see the paperwork. It was a very nice plane with spats and looked like a good buy for someone wanting to have a unique original specimen. He wanted to sell it but it wasn't something I was looking for.
TurboBeaver
Registered User
Northern Maine
Pete,
He is looking at an "amended" W&B on that 12 that some mechanic who flunked math class, must have done those calculations.
2 things you can count on is it didn't actually weight 800lbs on floats, and it didn't come from the factory with flaps.....
Folks often confuse the 14's with 12's and of course the 14's did come from the factory with flaps. The Mardens Airways original mod for flaps on a 12 simply used all factory 14 parts to do the conversion.
Down to the flap handle being on the RIGHT side of the seat!!![emoji2957] Still a few floating around Maine with handle on right
side! I have a Cub that shows an empty weight of 860 lbs when it was built in 1983 by Don Snyder in Pa that holds the STCs for
Lots of PA12 mods........ That weight is of course another fairytale. We are going to do an actual W&B on it this fall (digital scales) when it comes off floats. The number will likely be north of a 1000lbs........... Just the facts of life, when it comes to Cub/Cruiser weights.[emoji2958]
Sent from my moto e5 go using SuperCub.Org mobile app
He is looking at an "amended" W&B on that 12 that some mechanic who flunked math class, must have done those calculations.
2 things you can count on is it didn't actually weight 800lbs on floats, and it didn't come from the factory with flaps.....
Folks often confuse the 14's with 12's and of course the 14's did come from the factory with flaps. The Mardens Airways original mod for flaps on a 12 simply used all factory 14 parts to do the conversion.
Down to the flap handle being on the RIGHT side of the seat!!![emoji2957] Still a few floating around Maine with handle on right
side! I have a Cub that shows an empty weight of 860 lbs when it was built in 1983 by Don Snyder in Pa that holds the STCs for
Lots of PA12 mods........ That weight is of course another fairytale. We are going to do an actual W&B on it this fall (digital scales) when it comes off floats. The number will likely be north of a 1000lbs........... Just the facts of life, when it comes to Cub/Cruiser weights.[emoji2958]
Sent from my moto e5 go using SuperCub.Org mobile app
RaisedByWolves
FRIEND
Tx
You may not want to weigh it. Or don’t record it.
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jwmusgrove
FRIEND
My experience with both was the PA12 was much closer to the PA18 when on floats, in T/O mode, as opposed to on wheels.
With the "Borer rudder centering mod", the -12 always felt longitudinally unstable on floats.
With stock door, the -12 was like getting in, proceeding down a short hallway, then settling into the seat. This got a little more difficult with a life jacket or a parka on. Not so bad with the -18.
In the -12, NO room between my knees and the bottom of the dash. -18 was better.
As previously mentioned, with 3 people, the -12 did much better on CG. Also remember, the rear seat requires the 3000# belt. Seen some with the standard 1500 pounder.
My 2 ¢ worth.
skywagon8a
MEMBER
SE Mass MA6
This type of mod (not just on the -12) is only a band-aid fix for an airplane that needs more vertical tail area. All it does is to BS the FAA into approving an installation. The ventral fin is required by the Type Certificate when a -12 is on floats. The Borer STC eliminates the ventral fin requirement, which is why the -12 with the STC is longitudinally unstable on floats. More vertical tail area = more longitudinal stability.
I can +1 pretty much all your PA-12 flying experiences in this post Bill
My PA-12 is almost completely standard, although now with an O-235-C2C rather than its original O-235-C and interesting that it sounds the same as the 150hp version!! I 1,000,000% agree with the short landing technique, as until I started landing mine like the Pitts S-1S which is side slip pretty much all the way to the flare, I was consistently floating on, whereas the side slip adds REAL speed and rate of height loss control. I also agree with the standing up and lying down analogy with getting in and to be honest, that's the one thing I miss about the PA-18........ I was taught the "sit on the door hinge, hold the windscreen vertical bar, lean back and swing your legs in" technique by a WW2 pilot who originally learned on a Cub when I started flying the 18 and I find the squeezing round and into the front seat of the 12 a lot less fun and elegant :roll: I agree that the aileron feel is a lot lighter than the 18 and maybe why the roll rate feels better?
On trim, I again completely agree that the stick force gets VERY heavy when out of trim and one of my most effective mods has been to mount the trim handle in oilite bearings, which at least makes the almost constant trimming a lot more pleasant experience!!!
Philly
TurboBeaver
Registered User
Northern Maine
Phil,
The roll rate feels better because it IS better, the ailerons on the 12 have ALOT more travel BOTH ways than the 18 does,
And the leading edge of the ailerons is arguably of a better design. Togeather they do give you that feel you are " feeling"...... Piper got it right with the 12 aileron system; But must have decided, it was just to expensive, to use that system In the 18 series ? Cub Crafters basically went back to the 12 type system, on the new X series,
To take advantage of that system.
Cheers
E
Sent from my moto e5 go using SuperCub.Org mobile app
The roll rate feels better because it IS better, the ailerons on the 12 have ALOT more travel BOTH ways than the 18 does,
And the leading edge of the ailerons is arguably of a better design. Togeather they do give you that feel you are " feeling"...... Piper got it right with the 12 aileron system; But must have decided, it was just to expensive, to use that system In the 18 series ? Cub Crafters basically went back to the 12 type system, on the new X series,
To take advantage of that system.
Cheers
E
Sent from my moto e5 go using SuperCub.Org mobile app
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Gordon Misch
MEMBER
Toledo, Wa (KTDO)
Flew a buddy's -18 a few days ago, in part to compare with my -12. It seemed a little less responsive in roll, but comfortable, and MUCH lighter in pitch - with seemingly greater stick deflection. Edit: It seemed delightfully well balanced in all three axes.
At least part of that is different geometry in the stick to base connector link. His has somewhat less measured distance between pivot point to torque tube centerline than mine. My understanding, per Mr Ed's research, is that Piper made some changes in that geometry around 1960 or thereabouts. That would certainly explain a difference.
SuPilot - what was your comparative impression re stick force/deflection between your 18 and my 12?
At least part of that is different geometry in the stick to base connector link. His has somewhat less measured distance between pivot point to torque tube centerline than mine. My understanding, per Mr Ed's research, is that Piper made some changes in that geometry around 1960 or thereabouts. That would certainly explain a difference.
SuPilot - what was your comparative impression re stick force/deflection between your 18 and my 12?
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behindpropellers
Registered User
NE Ohio
I used to know this, I think it is something like .375" difference on the bottom pivot to the torque tube pivot.
Tim
Gordon Misch
MEMBER
Toledo, Wa (KTDO)
I think it's more than that. He sent me a measurement a day or two ago, and I think it was more like an inch+ in comparison to Piper's PA-12 drawing and the Exp I'm working on now.
I don't have actual numbers in front of me though, so as usual, I could be significantly wrong.
I don't have actual numbers in front of me though, so as usual, I could be significantly wrong.
skywagon8a
MEMBER
SE Mass MA6
Gordon brings up a good point about the differences in control forces re: ailerons. The length of that arm will reduce the forces required to move the ailerons when it is shortened. However it will also reduce the amount the aileron moves, since the cable will not move quite as far as it used to. C=Pi x D
When making alterations to a control system while wanting to make a certain improvement, you must look at the entire system to learn what else will be changed at the other end. In this case of reducing control pressures (making it lighter) your maximum rolling authority would also be reduced.
For example, if you were building your own plane wanting to reduce the control pressures by shortening the length of the arm under the torque tube, you could retain or even improve the authority of the ailerons by moving them further outboard. This gives the ailerons a longer leverage arm when banking the wings thus reducing the force required.
When making alterations to a control system while wanting to make a certain improvement, you must look at the entire system to learn what else will be changed at the other end. In this case of reducing control pressures (making it lighter) your maximum rolling authority would also be reduced.
For example, if you were building your own plane wanting to reduce the control pressures by shortening the length of the arm under the torque tube, you could retain or even improve the authority of the ailerons by moving them further outboard. This gives the ailerons a longer leverage arm when banking the wings thus reducing the force required.
supercrow
FRIEND
Smith Pond near Millinocket, Me
I changed the stick to base length when I changed to the s. cub type elevator cable system. The J-3/12 system doesn't use the pully that is between your feet in the center of the front floorboard. The s. cub type is much smoother. My ailerons are outboard without stops on them and I used bearing pulleys there and for both elev. cables. Makes for pretty smooth operation all around for a cub type control system. Those who have flown it say it is very smooth and responsive. And as Pete said the leverage of the ailerons outboard make for easy float lifting at speeds lower than you might expect. Works for me anyway. If someone needs it, the old bushed holes are still in my sticks and I can measure the difference in the old hole and the new one.
Alex Clark
Registered User
Life Long Alaskan
I like instructing floats in 12s because I can see around the front seat occupant. To me a 160 hp 12 with flaps is almost as good performance wise as a PA-18 -160. But in a steep bank at low speed I would rather be in a 18. On wheels the 18s seem to have more of the advantage except in cruise if they have the 12 gear.
I used to own a J5A that had flapless 12 wings, PA-20 tail feathers and a O-290, 125 horse. It was a dream to fly on wheels and weighed 1,004 pounds empty, with a battery and starter. Far better than any 12 I have flown.
And my old PA-11 90 horse ( Cub Special ) was the queen of low speed yanking and banking. Stock wings, 18 rudder, stock elevators, no electrical at all... She was much more agile than any 18 or 12 I have ever flown and much better than my old J5.
I used to own a J5A that had flapless 12 wings, PA-20 tail feathers and a O-290, 125 horse. It was a dream to fly on wheels and weighed 1,004 pounds empty, with a battery and starter. Far better than any 12 I have flown.
And my old PA-11 90 horse ( Cub Special ) was the queen of low speed yanking and banking. Stock wings, 18 rudder, stock elevators, no electrical at all... She was much more agile than any 18 or 12 I have ever flown and much better than my old J5.
Attachments
brekkeaerial
MEMBER
Lake Metigoshe, ND
Pa-12 vs pa-18
I owned both a 150 hp 12, with an 18 tail with flaps, and a pa-18 a the same time for many years. I loved the 12, and thought it performed as good as my 18. The only thing I didn’t like about the 12, was as I was getting older, it was harder for me to get in and out if it. I had developed a techinique for getting in and out of the 18, but never did find an easy way to get in and out of the 12
I owned both a 150 hp 12, with an 18 tail with flaps, and a pa-18 a the same time for many years. I loved the 12, and thought it performed as good as my 18. The only thing I didn’t like about the 12, was as I was getting older, it was harder for me to get in and out if it. I had developed a techinique for getting in and out of the 18, but never did find an easy way to get in and out of the 12
Alex Clark
Registered User
Life Long Alaskan
In my 12 and J5, I would remove the back stick and first get into or over the rear seat. Then lean forward and walk each leg around the front seat and then sit down up front.
I guess I’m in the minority. 18 is easy to get in and out except in winter when I have lots of layers on. 12 is easy to get in and out of all year. For the twelve with a long step. Start behind the struts, step one foot on very back/rear of long step, next step is up front, use v brace to stabilize, plant butt in front seat. When exiting I come out in front of struts with one foot on tire then down to ground. For me the 12 feels like I’m walking into it and the 18 requires a bit of flexibility.
How much weight does it add installing the O-320. I was considering a -12 with a stock engine m no mods. I thought the stock engine was an o-290 125 hp? I’m a fair weather grass strip Flyer. Used to own a J3 but I do not like hand propping. I though the -12 might be a good match. Thx!
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skywagon8a
MEMBER
SE Mass MA6
The original stock engine is the 0-235, 100 hp. The alternate engine was 0-235C1 of 108 hp or 115 hp at a higher rpm. The 0-290 was a common alteration during the 1950s.
Alex Clark
Registered User
Life Long Alaskan
Somebody may have mentioned this already but.
Running a PA-12 on floats has one advantage right out of the gate.
The original gross weight for a PA-12 on floats is 1838 pounds compared to the 1760 for a PA-18.
And of course there are more than a few PA-12s with the 1935 pound gross weight increase. Maybe
more than PA-18s with the one ton STC.
Why Piper and the FAA gave the PA12 a leap from 1750 on wheels to 1838 on floats, while only going from 1750 to 1760 for the PA-18 is one of life's mysteries.
Running a PA-12 on floats has one advantage right out of the gate.
The original gross weight for a PA-12 on floats is 1838 pounds compared to the 1760 for a PA-18.
And of course there are more than a few PA-12s with the 1935 pound gross weight increase. Maybe
more than PA-18s with the one ton STC.
Why Piper and the FAA gave the PA12 a leap from 1750 on wheels to 1838 on floats, while only going from 1750 to 1760 for the PA-18 is one of life's mysteries.
behindpropellers
Registered User
NE Ohio
Doug,
There is a drawing to install that tube to make it work on floats. At this point, I think most of them have it.
Tim
skywagon8a
MEMBER
SE Mass MA6
From the TC A-780
Landing Gear and Floats,
204. Edo 89-2000 floats with water rudder and seaplane fin (Dwg. No. 11030) +183 lbs. (+14.5)
in accordance with Piper Dwg. 11031 (without spreader bars) orEdo Dwg. 89-180A (with spreader bars). Airplane Serial Nos. 12-1 through 12-3011,and 12-3901 through 12-3966, except 12-3943, 12-3945, 12-3947, 12-3949 and 12-3965, must have additional fuselage brace tubes (Parts Nos. 11026 and 11027 in accordance with Piper Dwg. 11031).
Doug, The -12 and the -12S are the same except for the landing gear with the associated required equipment. The differences in gross weight are likely based upon the landing loads on the airframe. The additional weight of the floats are not considered in the drop tests since the airframe is dropped onto the floats.
Landing Gear and Floats,
204. Edo 89-2000 floats with water rudder and seaplane fin (Dwg. No. 11030) +183 lbs. (+14.5)
in accordance with Piper Dwg. 11031 (without spreader bars) orEdo Dwg. 89-180A (with spreader bars). Airplane Serial Nos. 12-1 through 12-3011,and 12-3901 through 12-3966, except 12-3943, 12-3945, 12-3947, 12-3949 and 12-3965, must have additional fuselage brace tubes (Parts Nos. 11026 and 11027 in accordance with Piper Dwg. 11031).
Doug, The -12 and the -12S are the same except for the landing gear with the associated required equipment. The differences in gross weight are likely based upon the landing loads on the airframe. The additional weight of the floats are not considered in the drop tests since the airframe is dropped onto the floats.
