So I reached out to Atlee Dodge (which now owns the Fluidyne type of ski) to inquire about coil springs to replace the bungees installed on my 3200s. Alas, they replied to say 'they know of no legal spring for that application.'

Any suggestions from the forum on where to turn next?

Boreal1 wrote:So I reached out to Atlee Dodge (which now owns the Fluidyne type of ski) to inquire about coil springs to replace the bungees installed on my 3200s. Alas, they replied to say 'they know of no legal spring for that application.'

Any suggestions from the forum on where to turn next?

I also briefly researched a possible switch from bungee to spring on our Federal AWB 4820's and received the same response from FA Dodge (FAD). I came to the conclusion that the only certified route to go is a field approval/one-time STC which requires some significant testing on the springs chosen for the task. I run FAD springs on our PA-18 (silver) and the gold springs on our 180 with Landes (Airglas) straight skis. However, I have not seen springs employed on Federal hydraulic skis. There may be a very good reason for this. With higher yield projects competing for my time, I decided to stick to the bungees as designed and called out in the Federal drawings.

I would suggest relaxing the bungee when sitting for extended periods (especially in severe cold). This may be impractical with 180 and above size aircraft. When I ran bungees on Cubs, I set the tail spring on a sawhorse to relax the bungee when not in use. I believe this practice extended the life of the cords; however, this is merely anecdotal data.

TR

Wow! That surprises me. Try getting in touch with Jon at Northland Aviation in Fairbanks. I know they serviced that 185 in the photo I posted, many times, and others with springs. I suspect those springs were field approved. Or, get in touch with Nathan or Mark at Chena Marina Air, also in Fairbanks.

When I bought a brand new set of Aero 3000 skis for my personal Super Cub, they came with springs instead of bungees. Mechanic installed them, as delivered from Aero Ski. FAA got their knickers in a knot over the springs, and threatened legal action on the mechanic.....even though we explained, and Aero Ski verified that the skis were delivered new with springs.

Turned out to be much ado about nothing, and the FSDO signed a Field Approval for springs vs bungees. But, as a pilot, I never asked the question about the 185 work planes.....but our mechanics tried pretty hard to keep our planes "legal", even though they were feds.

MTV

Thanks for those leads. Of course, Transport Canada will have their own ideas about what qualifies for a field approval, so i'll see if i can find some shops here that may have gone down this particular rabbit hole as well.