Results 1 to 11 of 11

Thread: Federal c2200 Ski Bungees

  1. #1

    Join Date
    Jan 2020
    Location
    Austria
    Posts
    6
    Post Thanks / Like

    Federal c2200 Ski Bungees

    Hi there!
    Im in a set up process of an Airplane with Federal c2200 from 1962. The Plane is build in 1966 according to CAR3, so my authority supports me at that project with something like a "National single AC-STC". The Skis were mounted on a Supercub "100 years ago" then a very very long time in the basement somewhere. I`ve got them from the Internet almost complete. I restored this and that and made all hoses new etc... I also got and will get new bungees from wip, and here is my question:
    Front bungee tension:
    Its close to "very little" (less than 5% tension length) when Skis up or down in Flying position on my AC. "Ski down tail down" is approximately 14% tension (+7cm). And when pumping the AC on ground from "Ski down to Ski up" the front bungees are moving from 14% (+7cm) to 27% (+13cm) back to less than 5% tension. How is that Value on Cubs/Huskys?
    Rear bungee mechanism:
    I understand the working principle but what are they basically for? Is this mechanism designed for preventing damage at aft cables, attaching points or fuselage tubing when the skitip moves up more than expected due to terrain ? Any ideas, tips?
    Are there some Federal Skis operated with steel springs (front or aft)?
    Thank you!

  2. #2

    Join Date
    May 2017
    Posts
    533
    Post Thanks / Like
    Quote Originally Posted by JOB15 View Post
    Hi there!
    Im in a set up process of an Airplane with Federal c2200 from 1962. The Plane is build in 1966 according to CAR3, so my authority supports me at that project with something like a "National single AC-STC". The Skis were mounted on a Supercub "100 years ago" then a very very long time in the basement somewhere. I`ve got them from the Internet almost complete. I restored this and that and made all hoses new etc... I also got and will get new bungees from wip, and here is my question:
    Front bungee tension:
    Its close to "very little" (less than 5% tension length) when Skis up or down in Flying position on my AC. "Ski down tail down" is approximately 14% tension (+7cm). And when pumping the AC on ground from "Ski down to Ski up" the front bungees are moving from 14% (+7cm) to 27% (+13cm) back to less than 5% tension. How is that Value on Cubs/Huskys?
    Rear bungee mechanism:
    I understand the working principle but what are they basically for? Is this mechanism designed for preventing damage at aft cables, attaching points or fuselage tubing when the skitip moves up more than expected due to terrain ? Any ideas, tips?
    Are there some Federal Skis operated with steel springs (front or aft)?
    Thank you!
    Please explain what you mean The Plane is build in 1966 according to CAR3, so my authority supports me at that project with something like a "National single AC-STC". That doesnt make any sense. Either they are approved on your aircraft or they arent. If there is no cerebral approves data to install them, then you need to get approved data. Doesnt matter what the certification basis is, you still need approved data, just meets that the data only needs to meet CAR 3 requirements.


    Sent from my iPhone using Tapatalk
    Thanks eviens thanked for this post

  3. #3

    Join Date
    Jan 2020
    Location
    Austria
    Posts
    6
    Post Thanks / Like
    Yes the skis are approved for my aircraft size and weight (lets say they fit..). But my AC is the first and one and only of this type to be fitted with skis, and thats what Im doing. Including the mounting, ground testing and flight testing according to CAR3. So I also have to determine all the necessary data. So its a "little" project. Where I come from, flying with skis is not so popular so i try to get some information from here and there, or to hear an opinion to this and that just to build up knowledge and to learn. Do you know something interesting about bungees? or springs? experience in ski flying?

  4. #4
    mvivion's Avatar
    Join Date
    Jun 2003
    Location
    Bozeman,MT
    Posts
    10,623
    Post Thanks / Like
    Quote Originally Posted by JOB15 View Post
    Hi there!
    Im in a set up process of an Airplane with Federal c2200 from 1962. The Plane is build in 1966 according to CAR3, so my authority supports me at that project with something like a "National single AC-STC".
    Rear bungee mechanism:
    I understand the working principle but what are they basically for? Is this mechanism designed for preventing damage at aft cables, attaching points or fuselage tubing when the skitip moves up more than expected due to terrain ? Any ideas, tips?
    Are there some Federal Skis operated with steel springs (front or aft)?
    Thank you!
    Sounds like an interesting project. What type aircraft, a European built type?

    I can't answer the first couple of questions, but the rear cables "extend/retract" to maintain constant length and tension on the aft cables as the skis are raised or lowered. These skis move fore and aft quite a lot as they cycle, which would change the tension on the aft limit cables.

    As to springs vs bungees, I've seen springs used in the forward cables on Cessnas, where the forward attach point is high on the cowling. Tension there is important, because too much slack in the spring and those things will bang up the cowling. And, those setups offer a long length.

    Give us a picture of the project plane. It sounds like an interesting project.

    MTV
    Thanks JOB15 thanked for this post

  5. #5

    Join Date
    May 2017
    Posts
    533
    Post Thanks / Like
    Quote Originally Posted by JOB15 View Post
    Yes the skis are approved for my aircraft size and weight (lets say they fit..). But my AC is the first and one and only of this type to be fitted with skis, and thats what Im doing. Including the mounting, ground testing and flight testing according to CAR3. So I also have to determine all the necessary data. So its a "little" project. Where I come from, flying with skis is not so popular so i try to get some information from here and there, or to hear an opinion to this and that just to build up knowledge and to learn. Do you know something interesting about bungees? or springs? experience in ski flying?
    Start with a certification checklist, and develop a certification plan. Go through CAR 3 (check the revision date), and list every regulation that will be impacted by the change. Once you figure what regulations you need to show compliance to, then figure the method you will use to show compliance, test, analysis, whatever. All that goes into your certification plan along with what DERs and DARs you plan on using for the certification. Present that to the ACO with an application for an STC. FAA has a good book, guide to Project Specific Certification Guide.


    Sent from my iPhone using Tapatalk

  6. #6
    mvivion's Avatar
    Join Date
    Jun 2003
    Location
    Bozeman,MT
    Posts
    10,623
    Post Thanks / Like
    Quote Originally Posted by dgapilot View Post
    Start with a certification checklist, and develop a certification plan. Go through CAR 3 (check the revision date), and list every regulation that will be impacted by the change. Once you figure what regulations you need to show compliance to, then figure the method you will use to show compliance, test, analysis, whatever. All that goes into your certification plan along with what DERs and DARs you plan on using for the certification. Present that to the ACO with an application for an STC. FAA has a good book, guide to Project Specific Certification Guide.


    Sent from my iPhone using Tapatalk
    His location is shown as Austria. I’m not sure he needs to worry about the FAA.

    MTV

  7. #7

    Join Date
    May 2017
    Posts
    533
    Post Thanks / Like
    Quote Originally Posted by mvivion View Post
    His location is shown as Austria. Im not sure he needs to worry about the FAA.

    MTV
    Didnt see that! Thanks.


    Sent from my iPad using Tapatalk

  8. #8

    Join Date
    Jan 2020
    Location
    Austria
    Posts
    6
    Post Thanks / Like
    Click image for larger version. 

Name:	IMG_5132.JPG 
Views:	51 
Size:	319.8 KB 
ID:	46513Click image for larger version. 

Name:	IMG_5132.JPG 
Views:	51 
Size:	319.8 KB 
ID:	46513Click image for larger version. 

Name:	IMG_5159.JPG 
Views:	45 
Size:	758.0 KB 
ID:	46514

  9. #9

    Join Date
    Jan 2020
    Location
    Austria
    Posts
    6
    Post Thanks / Like
    This is the situation now, bungees are not yet the originals, so a little bit of setup-adjusting has to be performed. Tailski is not finished yet.


    Gesendet von iPhone mit SuperCub.Org

  10. #10

    Join Date
    Jan 2020
    Location
    Austria
    Posts
    6
    Post Thanks / Like
    Quote Originally Posted by dgapilot View Post
    Start with a certification checklist, and develop a certification plan. Go through CAR 3 (check the revision date), and list every regulation that will be impacted by the change. Once you figure what regulations you need to show compliance to, then figure the method you will use to show compliance, test, analysis, whatever. All that goes into your certification plan along with what DERs and DARs you plan on using for the certification. Present that to the ACO with an application for an STC. FAA has a good book, guide to Project Specific Certification Guide.


    Sent from my iPhone using Tapatalk
    Yes! Thats exactly what im doing with my national aviation authorities.
    Likes dgapilot liked this post

  11. #11

    Join Date
    Jan 2020
    Location
    Austria
    Posts
    6
    Post Thanks / Like
    Thanks for the questions/answers! According to the front bungees, meanwhile I got answer from the manufacturer, they test this rings up to 15". So no problem with my 5" during ski travel on ground. I think on other planes it will be quite the same!

Similar Threads

  1. Federal C2200 Hydraulic Skis
    By WindOnHisNose in forum Tips and Tricks
    Replies: 9
    Last Post: 01-09-2010, 08:57 AM
  2. Federal C2200 hydraulic skis
    By WindOnHisNose in forum Modifications
    Replies: 0
    Last Post: 01-12-2008, 09:12 AM

Tags for this Thread

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •