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Thread: Rigging Wipline 2100S to Patrol

  1. #41
    skywagon8a's Avatar
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    Hmmm? Never thought of dropping the water rudders. I'd be apt to forget and land with them down and as you know that will beat them all to pieces if you forget often enough. I can see how that would help though, as they would be in undisturbed air.

    That extra bit of tail area that you had on the 12 probably made more difference than you thought.
    N1PA

  2. #42
    mvivion's Avatar
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    I’ve flown quite a few hours with ventral fins, on Beavers, Cessnas, PA-12, and Huskys primarily, and I’m with Pete....they definitely help stability. They can be a little nuisance with beaching and high banks, but you just learn to deal with it.
    But the instability is always there, every flight. My 170 float STC did not require a fin, it a fin was included in the STC as an option. Didn’t take me long to understand why, and I installed one. Never looked back. As Pete noted, it was a very tiring plane to fly without the fin, and only moderately so with.

    The “finlets” resolve both issues to some degree, and on an EX no approval required. They’d be easy to fabricate, as well. The Husky and 12 ventral fins are pretty big

    MTV
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  3. #43
    BC12D-4-85's Avatar
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    One summer I flew my 7GCBC without factory fins. It wasn't bad. I guess I got used to them being absent. Then I had the wings extended and Ferguson tips. It would hunt around the flight course so I put them back on. From that I gathered long wings likes fin(s).

    I then made up a set of one piece fins from plate aluminum (like the Beaver's) that would bolt onto the end of the stabilizer with two aluminum angles, one on top and below the outboard stabilizer edge. But the plane flew south for a PA-18A and I never used them.

    One interesting thing is that Taylorcraft requires a ventral fin with EDO 1320 and 1400 floats unless a C-85 is installed or rear CG limited - then none is required. Not sure what aft CG does in that case. My fin sleeps indoors.

    TCDS A-696: (a) Model 60-1320 and 1400 floats
    Auxiliary fin (required on all models except BCS12D-85 and BCS12D-4-85 unless the
    seaplane aft C.G. limit for maximum weight is reduced to +18.9).

    Gary
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  4. #44
    skywagon8a's Avatar
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    Now you are getting into the finite details Gary. The 7GCB had the old round Aeronca tail with the dorsal fin extension. Without any fins when the rudder was pushed it would skid 30 or 40 degrees and stay there when you took your feet off the pedals. This on EDO 2000s. I don't recall whether the Ferguson tips were on it or not at the time. The 7GCBC has a taller higher aspect ratio tail so would have a bit more stabilizing effect. From old engineering books and 1920s & 30s airplane magazines you will find information on how the tail volume is in proportion to the wing span. Yes, more span requires more vertical tail.

    As I noted above in #37 the stability has to do with the vertical areas forward and aft of the CG being balanced. This reflects on what you noted in the TCDS A-696.

    Fun discussion, hopefully Clayton is paying attention and will be better informed when his bird flies.
    N1PA
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  5. #45
    BC12D-4-85's Avatar
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    Finite is funner. Post-WWII Taylorcrafts had a taller vertical stabilizer and rudder, but the rudder had less chord. Word on the aerodrome was the tall vert offset adverse aileron yaw better. But by then Taylorcraft quit float testing starting with the Model 19 and left STC approval for manufacturers.

    Edit Some evolutionary changes to floatplane configurations may have occurred as models were re-certified from early CAR Part 4 to later Part 3 flight manual aircraft. I'll have to read and compare my copies. Just a thought.

    Gary
    Last edited by BC12D-4-85; 05-12-2019 at 04:56 PM.
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  6. #46
    SuperDuper's Avatar
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    [QUOTE=Fun discussion, hopefully Clayton is paying attention and will be better informed when his bird flies.[/QUOTE]

    Reading every post and really appreciate the experience and input from all you guys.

    As for the EXP Patrol install - we did get the fuselage hung over the floats and positioned into what we think will be very close to the final orientation. I am hesitant to cut struts until I have my plane complete with wings on, engine, prop, avionics, etc for an accurate W&B. The primary objective was achieved in the fact that we now have a location and method to mount the rudder cable, balance cable, and retract pulleys. Should be a pretty slick installation, patterned much after Bill's design. We can do the final fab and finish up painting now.

    Looks like next spring is the best case scenario for floating the Patrol. Still need to finish up with paint, final assembly, and flying the hours off on wheels first.

    The great thing about this discussion is the fact that I now know my J-3 is rigged wrong. No way I have the right birds mouth with that particular set up - which I will confirm in a few weeks. I will gladly give up some cruise airspeed in exchange for a few seconds of take off performance - might even allow me to load that thing up and head North this summer. If it would only improve the range

    All the Best,

    Clayton
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  7. #47
    skywagon8a's Avatar
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    Quote Originally Posted by SuperDuper View Post
    As for the EXP Patrol install - we did get the fuselage hung over the floats and positioned into what we think will be very close to the final orientation. I am hesitant to cut struts until I have my plane complete with wings on, engine, prop, avionics, etc for an accurate W&B. The primary objective was achieved in the fact that we now have a location
    How close to the correct length do the struts appear to be? Consider that you could swap front to rear struts for a possible better fit. Can you show us a picture of what you have done with the floats under the fuselage and the struts resting along side? This will give us an opportunity to think on it as well as you.
    N1PA

  8. #48
    BC12D-4-85's Avatar
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    Clayton...you mentioned J-3. What floats are installed? If they're EDO 1320's or 1400's there's various struts that yield different configurations.

    Gary
    Last edited by BC12D-4-85; 05-13-2019 at 10:38 AM.

  9. #49
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    Quote Originally Posted by BC12D-4-85 View Post
    Clayton...you mentioned J-3. What floats are installed? If they're EDO 1320's there's various struts that yield different configurations.

    Gary
    They are Aqua 1500's.
    My point of reference here is the Jack Brown Seaplane folks. I got my SES rating there with the same plane/float set up. Have flown mine for two seasons, and can not break loose from the water when at GW without lifting a float. I have plenty of water to work with here, but seriously, if I am going to make any kind of cross country trips I really need to open the birds mouth up some for take off performance - even if I have to stop every 110 minutes, instead of every 120 minutes

    Another contributing factor is the fact that I have bolt on rear attachments, which probably account for at least 1/2" of additional closure. I have never checked the angles, just bolted on and flew. Will get the smart level out and check things over this year - pretty sure I now know the answer thanks to this thread.

  10. #50
    BC12D-4-85's Avatar
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    Ok Aquas. I've never been to Browns only via pictures and stories from those that have locally. I've never flown those floats as well. But from what I've seen there's definitely room for improvement especially if the deck angles are flatter then optimum. There's only been Taylorcrafts on them locally.

    They are a heavy float with lots of flat bottom to create water friction. Other models on bigger planes appear to stick to the water also probably by their bottom design. Adding a second set of angles (like sister keelsons) to break suction might help. Same for more bird mouth. Check that out and maybe add a degree or two and see what happens. Don't let algae build up either. Keep them cleaned or performance will suffer.

    What engine and prop does your J-3 have?

    Gary

  11. #51
    skywagon8a's Avatar
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    Before you make any changes to the float installation on the J-3, put some baggage in the baggage compartment or tie on a chunk of lead at the tail post to pull the CG aft. 5 or 10 pounds of lead at the tail post will make a great deal of difference without sacrificing any cruise speed.
    N1PA

  12. #52
    BC12D-4-85's Avatar
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    Maybe Clayton has info on a normal load CG for his J-3 to share before any adjustment?

    Gary
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  13. #53
    SuperDuper's Avatar
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    Quote Originally Posted by BC12D-4-85 View Post
    Maybe Clayton has info on a normal load CG for his J-3 to share before any adjustment?

    Gary
    Gary,

    To answer your earlier question, when on floats I am using a McCauley 70/40 prop with a C85, turning 2550 off the water.
    On wheels, I am running a 71/44 McCauley, static of 2250, 2400 on the roll.
    I have run both props with the floats and the 70/40 makes a big difference.

    This set of Aquas does have sister keelsons.

    I will be sure and get W/B - CG info posted once I am back on the floats. Will also get the birds mouth info together and posted.

    Pete - really like your suggestion of the lead at the tail post. Should be easy to do and easy to quantify improvement in performance. Regarding cruise speed, as configured with the floats now, I am seeing no measurable difference (based on the ASI) between wheels and floats. I will be sure and get the GPS out and establish a bench mark while I am still on wheels. Not sure what I will plug the GPS into, but I will figure something out Oh yes - Yet another good reason to get out and do some flying

  14. #54
    BC12D-4-85's Avatar
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    Clayton, does the Aqua STC specify propeller and limits? I'd run as long a prop as allowed at spec'd static. Maybe Aqua refers back to a similar float tested previously by Piper and noted on the TCDS A-691. The 71" pitched to 41-42 might be interesting (~2350). By sister keelsons I meant maybe adding a second below the existing set to help performance. Ask Eddie Peck about that, his chine angle strip mod, and propellers (https://peckaero.ca/contact-us/). How fast is your cruise speed - rpm? My friend Dave that flew at Brown's said they had C-85 Strokers so maybe they know what's best on that float.

    Gary
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  15. #55
    cubdriver2's Avatar
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    Clayton, just shorten the rear strut a half inch ( one rivet/bolt hole ) like everyone else does. Not like your going to loose any speed in a J3?

    Glenn
    Last edited by cubdriver2; 05-13-2019 at 09:07 PM.
    "Optimism is going after Moby Dick in a rowboat and taking the tartar sauce with you!"
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  16. #56
    skywagon8a's Avatar
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    Clayton, GPS is just nice to know feel good stuff which varies with winds aloft. Indicated airspeed is the number which is important for this purpose. Sure you can get into all sorts of fancy different methods of collecting speed information. This is only a J-3, IAS is good enough. Since the speed is the same on wheels or floats, this is telling me that it is the engine/prop combination which is controlling speed not the airframe/float drag component. A propeller/engine combination is only going to screw through so much air. If the airframe drag is reduced the speed will be unchanged. If the drag is increased the speed may be reduced.

    The take off time may not be limited by the fish mouth angle. It is possible that the step is too far aft, which is why I suggested the ballast. When the step is too far aft, there is more up elevator force required to rotate to the lift off angle. This up elevator produces drag which retards acceleration. The ballast will reduce the amount of up elevator required., thus less drag and quicker acceleration.

    When you are running across the lake on the step, the elevator forces are balancing between the loaded CG and the pivot location of the float step. Moving those two points closer together reduces the rotation speed of the plane. When the step is too far aft in relation to the CG the airplane will be more likely to have porpoising tendencies.

    When the step is located far aft, the plane will get on the step more quickly.
    When the step is located far forward, the plane will get on the step more slowly since you will need more speed to lift the weight up onto the planning position.

    It is possible that Aqua located the floats at this location in order to reduce the area forward which caused a directional stability issue? Moving the floats forward to move the step may then require a fin on the tail. Again ballast is the better choice.
    Last edited by skywagon8a; 05-14-2019 at 05:42 AM.
    N1PA
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  17. #57
    SuperDuper's Avatar
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    Quote Originally Posted by skywagon8a View Post
    Clayton, GPS is just nice to know feel good stuff which varies with winds aloft. Indicated airspeed is the number which is important for this purpose. Sure you can get into all sorts of fancy different methods of collecting speed information. This is only a J-3, IAS is good enough. Since the speed is the same on wheels or floats, this is telling me that it is the engine/prop combination which is controlling speed not the airframe/float drag component. A propeller/engine combination is only going to screw through so much air. If the airframe drag is reduced the speed will be unchanged. If the drag is increased the speed may be reduced.

    The take off time may not be limited by the fish mouth angle. It is possible that the step is too far aft, which is why I suggested the ballast. When the step is too far aft, there is more up elevator force required to rotate to the lift off angle. This up elevator produces drag which retards acceleration. The ballast will reduce the amount of up elevator required., thus less drag and quicker acceleration.

    When you are running across the lake on the step, the elevator forces are balancing between the loaded CG and the pivot location of the float step. Moving those two points closer together reduces the rotation speed of the plane. When the step is too far aft in relation to the CG the airplane will be more likely to have porpoising tendencies.

    When the step is located far aft, the plane will get on the step more quickly.
    When the step is located far forward, the plane will get on the step more slowly since you will need more speed to lift the weight up onto the planning position.

    It is possible that Aqua located the floats at this location in order to reduce the area forward which caused a directional stability issue? Moving the floats forward to move the step may then require a fin on the tail. Again ballast is the better choice.
    I will be back this evening with more information

  18. #58
    BC12D-4-85's Avatar
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    I haven't ridden in a J-3 since 1948 so don't know much, but can they be flown from the front or rear on floats? Might make a difference for CG and performance. There's one being restored locally and it will have EDO 1320's so we'll find out next year.

    Gary

  19. #59
    SuperDuper's Avatar
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    I apologize for not getting back to the thread yesterday, but have been away from the computer.

    Regarding the J3 and the Aqua 1500s, let me provide some real numbers which might help troubleshooting.
    First - disregard my earlier claim that there is no loss in airspeed between wheels and floats. At this point I can not confirm that with hard numbers.
    I did get out and fly some this afternoon. Here is what I know:
    McCauley 71/44 Prop, C85 engine, 29" airstreaks
    At 2350 RPM, IAS 78 MPH, level flight trimmed at 55% (100% is full nose up)
    At 1800 RPM, IAS 50 MPH, level flight trimmed at 100% (Full nose up)

    This is a bench mark set of numbers that we can use to dial the J3 in when I am back on floats

    Although I do not recall exactly what the IAS is when on floats in straight and level flight, I do remember that I am nearly out of trim when on floats and in straight and level flight. I would say that number is right at 90% of nose up trim. This may help in some of the diagnosis.
    Another thing to consider, and keep in mind my experience is limited to the J3, is the fact that the time to get up on step seems very reasonable to me. The time on plane, between step and airborne, seems excessive to me. Recall, I have to lift a float to get airborne when at GW.

    To my way of thinking, the bigger the fish mouth, the more the plane would tend to pitch down once airborne, and therefore the more nose up trim required. Maybe my thinking is backwards here, so let me know.
    If my thinking is correct then shifting the CG aft, with ballast at the tail as Pete suggested, is the first change I am planning to start out with. Will keep the saw in storage for now.
    A side note here, the spring rains have the lakes up in this part of Oklahoma. Right now, we are 10.5 feet above normal. Won't be launching off the ramp anytime soon.

    Let me know if you see that there is more flight data that I need to collect while on tires - always looking for a good reason to go flying
    Last edited by SuperDuper; 05-15-2019 at 10:08 PM.

  20. #60
    BC12D-4-85's Avatar
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    Do you fly from the front or rear on wheels and floats? What's your CG for seating options on wheels and floats based upon current W&B? What CG limits does AQUA specify?

    Gary

  21. #61
    skywagon8a's Avatar
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    Quote Originally Posted by SuperDuper View Post
    ... I do remember that I am nearly out of trim when on floats and in straight and level flight. I would say that number is right at 90% of nose up trim. This may help in some of the diagnosis.
    Another thing to consider, and keep in mind my experience is limited to the J3, is the fact that the time to get up on step seems very reasonable to me. The time on plane, between step and airborne, seems excessive to me. Recall, I have to lift a float to get airborne when at GW.

    To my way of thinking, the bigger the fish mouth, the more the plane would tend to pitch down once airborne, and therefore the more nose up trim required. Maybe my thinking is backwards here, so let me know.
    If my thinking is correct then shifting the CG aft, with ballast at the tail as Pete suggested, is the first change I am planning to start out with. Will keep the saw in storage for now.
    Comments in red all indicate that the CG may be too far forward in relation to the step. Indicating that ballast is required.

    What are your official empty weight and CG numbers when on floats? I would like to do some math.
    As Gary asks, are you flying in the back seat solo?
    N1PA

  22. #62
    mvivion's Avatar
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    Quote Originally Posted by BC12D-4-85 View Post
    I haven't ridden in a J-3 since 1948 so don't know much, but can they be flown from the front or rear on floats? Might make a difference for CG and performance. There's one being restored locally and it will have EDO 1320's so we'll find out next year.

    Gary
    Yes, you can legally fly a J-3 from either seat IF you can get it within CG limits.

    And, yes, which seat he’s flying from is an essential data point.

    MTV

  23. #63
    BC12D-4-85's Avatar
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    Brown's Seaplane would have a copy of a basic W&B report for theirs that could be used to explore loading and CG info. With electronic flight bags W&B becomes an easy task. Then compare the results with aircraft performance and adjust.

    Gary

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