Curious whether a cub with floats gets wet enough that frame under covering should be checked for rust more often?
10 year old cub with rust?
Curious whether a cub with floats gets wet enough that frame under covering should be checked for rust more often?
10 year old cub with rust?
All tube and fabric aircraft should be checked or rust corrosion. Moisture accumulates and more if it lives outside, more still if its on floats. Just do a thorough inspection or find a knowledgeable party to do it. Does it have seaplane drain grommets in the wings, tail and fuselage belly? It should. Thanks Mark
Cub Crafters
Factory Direct New & Used Aircraft Sales
NorthEast & Great Lakes Region
518.410.9404
The steel tube members of an aircraft equipped with floats should be given par*ticularly close ~xamination.
It is possible for water to enter the interior of these members, allowing rust to form on the inside of the tubes while the exterior appears to be in good condi*tion. The best way to check for this condition is to have small holes strategically drilled in the tubing.
If water is present, it will run from the holes. It is sometimes desirable to have small pieces cut from critical tube mem*bers in order to obtain positive knowledge of the condition of the tube interiors.
Water does not enter the tubes. The tubes on our planes are sealed. If you drill holes, you destroy the integrity of those tubes making the airframe unairworthy. Those would need to be re welded to be airworthy, not a good plan.
You should be able through a thorough inspection on the exterior to tell if water has been present and done damage. With drain grommets (that are clear and open) the moisture should escape. Most older Cubs show moisture and or rust at the tail post and lower longerons at the tail post. This is an annual inspection and maintenance item. Our Cubs have a powder coated airframe to help reduce rust. My J3 on floats restored in 2007 has an epoxy primed airframe and last year was the first time I noticed rust on the tail post section. I wire brushed it and primed it.
Drilling would be a very last resort.
Cub Crafters
Factory Direct New & Used Aircraft Sales
NorthEast & Great Lakes Region
518.410.9404