Sea Fins PA12/14

[PA14driver]

I have drawings to install Sea Fins on my PA14. One is attached to each stabilizer. They are used in conjunction with the PA18 tail feathers. The original EDO Float installation had called for a dorsal fin, and I believe the intent of the Sea Fins was to replace the dorsal fin, as they had a habit of being "dock knockers".

Anybody have any comments, as to whether these are a good thing or not?

_____________________

PA14DRIVER

 

[RPURCELL]

Seafin

I flew my PA14 for two years on floats with Roger Borer's "Rudder Centering Device" which is an a STC. Avoids the two stabilizer fins or the fin under the rudder. Much cleaner installation. Basically just two centering springs on short cables from each side of the rudder horns forward to the lifting handles on the lower longerons.

 

[lp]

I have a pa-12 with the pa-18 tail on edo 2000's. Ive been using thee dorsal fin and find it a real pain in the butt first of all because it's a dock bumper and it drags in the water on take off. I would bee intyerested in anything that replaces it . l.p.

 

[mmr]

lp,
Do you know Bill Jackson of Jackson Air Services Ltd. ?

Mark

 

[lp]

Bill Jackson is a very good friend of mine , his float base is just down the road from my bodyshop. l.p.

 

[JimC]

Are you guys talking about dorsal fins or ventral fins? As I'm sure you know, the word 'dorsal' means 'on the top' and the word 'ventral' means 'on the bottom'. I can see why ventral fins would be dock-whackers, but have trouble seeing how dorsal fins would do so unless the docks have an unusal configuration.
All the best,
JimC

 

[lp]

My mistake Jim, I was talking about the ventral fin and calling it a dorsal fin but it is till a pain in the butt. I would like to replace it with something that works better. l.p.

 

[Crash]

Fin

Most of the guys here in Alaska don't run any fins on PA-18, 12's or 14's when on Edo 2000's. I have a PA-14 on Baumann 2100's and the STC dosn't call for a fin. I see these a lot on Canadian planes with fins so it must be your version of FAA requiring it for some reason. Crash

 

[JimC]

I.P. , what about enlarging the vertical stabiliser by an equivilent amount?
Jimc

 

[lp]

That might be a goood idea Crash but I can't see Ttransport Canada allowing the mod without an stc. l.p.

 

[RPURCELL]

sea fins

I purchased my PA-14 in Canada. The owner still had the ventral fin and offered it to me but I left it behind. It was not required on his plane in Canada because he had Roger Borer's Rudder Centering Device installed with Roger's STC. Saves weight, parts, and things to run into etc. It also works fine. A PA-14 does not need additional tail area. Shares the same basic tail profile as a PA-18 although it is a different part number.
Robert

 

[arvid]

sea fins

I purchased my PA-14 in Canada. The owner still had the ventral fin and offered it to me but I left it behind. It was not required on his plane in Canada because he had Roger Borer's Rudder Centering Device installed with Roger's STC. Saves weight, parts, and things to run into etc. It also works fine. A PA-14 does nothing need additional tail area. Shares the same basic tail profile as a PA-18 although it is a different part number.
Robert

Robert, do you find your PA-14 stable in yaw on floats though? Mine was absolutely terrible on Aqua2200 and I’m looking for fins to stabilize it longitudinal before putting them back on. Anyone know of an STC for fins?

 

[labrador_cub]

my pa12 has no fin, neither does the other 4 or 5 in my area. or any of the ones I have seen for sale on this side of canada for that matter. having never flown one with a ventral fin I cant say what the difference is, But I have never found either of the 12's I have time in unstable and wished I had one. that said, I did enlarge the vertical fin on the pa14 I am scratch building because its easy to do now and I plan on edo 2130's which are 8" longer then 2000's so maybe its needed then. but with 2000's there's times on a cross country my feet are off the pedals giving my legs and hips a break with a different position.

 

[arvid]

my pa12 has no fin, neither does the other 4 or 5 in my area. or any of the ones I have seen for sale on this side of canada for that matter. having never flown one with a ventral fin I cant say what the difference is, But I have never found either of the 12's I have time in unstable and wished I had one. that said, I did enlarge the vertical fin on the pa14 I am scratch building because its easy to do now and I plan on edo 2130's which are 8" longer then 2000's so maybe its needed then. but with 2000's there's times on a cross country my feet are off the pedals giving my legs and hips a break with a different position.

Thankyou for sharing your experiences. I’m not familiar with the details of a Pa-12 but I know the PA-14 wing has a lower angel of incidence compared to the PA-18. Guess piper experimentet with Cruise characteristics, hence the name! For example, during backwards sailing, the low tail would give me less wind veering resulting in almost a crab sail. How the different wing-setup effects level flight on floats beats my understanding though. It could all be due to bad rigging of too big floats…

 

[mvivion]

my pa12 has no fin, neither does the other 4 or 5 in my area. or any of the ones I have seen for sale on this side of canada for that matter. having never flown one with a ventral fin I cant say what the difference is, But I have never found either of the 12's I have time in unstable and wished I had one. that said, I did enlarge the vertical fin on the pa14 I am scratch building because its easy to do now and I plan on edo 2130's which are 8" longer then 2000's so maybe its needed then. but with 2000's there's times on a cross country my feet are off the pedals giving my legs and hips a break with a different position.

I have flown PA 12s on floats both with and without the ventral fin. I can attest that they do make a significant difference In lateral stability. I owned a Cessna 170B on PeeKay B2300 floats for many years. Initially, I flew it without the (optional) ventral fin. I wondered how in hell that float was ever certified on that plane without a ventral fin…..till I saw the certification data, and recognized an old friends name as test pilot. I bought a fin from PeeKay and never looked back.

 

[labrador_cub]

I have flown PA 12s on floats both with and without the ventral fin. I can attest that they do make a significant difference In lateral stability. I owned a Cessna 170B on PeeKay B2300 floats for many years. Initially, I flew it without the (optional) ventral fin. I wondered how in hell that float was ever certified on that plane without a ventral fin…..till I saw the certification data, and recognized an old friends name as test pilot. I bought a fin from PeeKay and never looked back.

If I had a fin I would defiantly try it and might very well be surprised how much better it is. but I have to say I love the way the 12 fly's as is. I guess once the 14 is done I'll get an idea of sorts, different plane but similar enough to notice after my time in the 12 I would think. the vertical fin on my 14 is 667 SQ.IN while a stock is 451 SQ.IN giving me and extra 216 SQ.IN which is 48% more vertical fin. plus the rudder will be enlarged accordingly. the hope is with all that I end up with a stable plane that has no fin hanging down because if I had one, I know it will be "when will I hit it" not "will I hit it some day". with this seasons extremely low water level I already skuffed a wing tip on the railing of my floating dock that for the first time ever gave up floating, by a foot at that!

 

[mvivion]

If I had a fin I would defiantly try it and might very well be surprised how much better it is. but I have to say I love the way the 12 fly's as is. I guess once the 14 is done I'll get an idea of sorts, different plane but similar enough to notice after my time in the 12 I would think. the vertical fin on my 14 is 667 SQ.IN while a stock is 451 SQ.IN giving me and extra 216 SQ.IN which is 48% more vertical fin. plus the rudder will be enlarged accordingly. the hope is with all that I end up with a stable plane that has no fin hanging down because if I had one, I know it will be "when will I hit it" not "will I hit it some day". with this seasons extremely low water level I already skuffed a wing tip on the railing of my floating dock that for the first time ever gave up floating, by a foot at that!

Frankly, if they’re approved, I’d try the “finlets” that attach to the outboard ends of the horizontal stab. If you’re exp, that’s definitely the way id go. It’s a win/win. I’ve operated Beavers with both the original fin and the finlets approved by Kenmore on that plane. The finlets work as well, and almost eliminate docking/beaching concerns associated with a big ventral fin.