Corrosion from sand off beaches.

Hello fellow cub pilots.

I operate my cub on beaches next to the ocean and just wondering if anyone knows from experience of this happening. Clearly landing on a beach and getting in and out of the airplane can drag unwanted sand particles from your shoes into the aircraft and when your flying the vibrations cause them to go to the tail of the aircraft, has anyone experienced serious corrosion in the tail of their aircraft due to the sand. I'm aware that the only way to stop corrosion is to not fly to the beach (but that's just boring) and im limiting the corrosion of the cylinder heads by having it specially coated with a antitrust material.

And any advice from how to stop sand getting in my airplane would be awesome
thanks
)

I don’t know about the sand, but salt spray from salt water will play havoc on all metals. Talk to anyone that operates a seaplane in salt water, or anyone that served on carriers.

Best advice would be anytime you’ve been to the beach, wash the airplane when you get home, maybe even rinse the inside of the fuselage, then go fly for a while to dry it out.


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Thanks for your response ,
every time i come home it gets a 4 hour cleaning bath. i know the salt air isn't too good and i dont think there is much i can do apart from be more careful when getting in and out of the cub. I know a mate gets the vacuum out and tries to get most of the sand out that way.

Is the aft cluster of the tail uncovered? Keeping that cluster open helps with cleaning.

MTV

Sand doesn't cause the corrosion, salt does. Can't stop corrosion but the thorough washing helps slow it. And keep an eye on your wheels. I've seen them turn into a weird swiss cheese due to salt corrosion.

Web

When you fly everything in the main cabin tends to go to right below the rear stick, not the tail (it is much higher in level flight). Whenever I loose a screw or washer up front I just have to fly for a bit and it shows up under the rear stick. I agree with the others sand is not the issue.
DENNY

mvivion said:

Is the aft cluster of the tail uncovered? Keeping that cluster open helps with cleaning.

MTV

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supercub2001 said:

....has anyone experienced serious corrosion in the tail of their aircraft due to the sand.

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As MTV mentioned, that rear most triangle in the bottom of the fuselage just in front of the tail post tends to collect dirt. The dirt holds moisture which in turn rusts out the longerons and lower tail post area. It matters not whether the moisture is fresh or has a high salt content. I always leave that triangle open as well as the aft lower triangle on the sides. It does help to have a removable belly panel which runs from the tail post to the leading edge of the stabilizer. This makes it easier to wash out with a hose an to clean the dirt out of the aft belly.

Exhaust fumes can enter that rear opening - no mystery - and move forward in the cockpit. A temp sponge plug can help. Some will install seaplane drain grommets strategically along the belly near trap spots for water sys dirt next to the longerons, fabric formers, and cross tubes. Flushing out the belly with water and/or a leaf blower can get rid of sand and spent shell casings.

Gary

BC12D-4-85 said:

Exhaust fumes can enter that rear opening - no mystery - and move forward in the cockpit. A temp sponge plug can help. Some will install seaplane drain grommets strategically along the belly near trap spots for water sys dirt next to the longerons, fabric formers, and cross tubes. Flushing out the belly with water and/or a leaf blower can get rid of sand and spent shell casings.

Gary

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The forward inside triangle of that opening can be covered with fabric for that purpose. That lower rear triangle above the tail wheel spring is very difficult to keep the dirt out of unless it has no bottom.

Installing a short rear metal belly triangle with formed drain channel and quick release fasteners makes servicing easy. Also helps hold up tail and resist tearing on skis.

Gary

Denny is right about the low point behind the pax stick/under seat. I found that spot and put two 3”x3” holes with grommets on both sides of belly stringer and made an exterior inspection panel. Usually twice a summer (fly ocean beaches lots) I set the tail up on a saw horse then dump 2 gallon pails of sh#tloads of water inside up at the firewall and completely flush underneath/top of the floor till nothing comes out. Then remove the under tail clean out pan lower tail then dump gallons of water under the rear seat area till it comes out clean. Check and clean tailpost area as well. Leave it open aired till dry then lightly wd40 rudder return springs and anything else that I can get to that needs it. In the fall I have a removable panel underneath the aft boot cowl and flush that once a year. I know it sounds like overkill but nearly 200 hrs since its rebuild (2016) and pounds of ocean sand and duck flat mud that has been cleaned out. I have no corrosion on rudder Springs or anything I can see under floor with a mirror. When I was a growing up in Dillingham I saw a few planes that had horrific belly corrosion, one had about 10 pounds of sand under the floorboards. I swore if I ever had the opportunity to maintain a Super Cub it would be better than those examples.

Water upon returning home. Lots of fresh water. Change out your wheel bearing grease a couple times a year also it you are inclined.

I flew floats on salt, and lots of beaches also. I would bucket water into the plane, through the tail, or a hose works. I would also pour water inside on the floor and let it wash down.

I like the ideas of inspection panels in places, I will incorporate that next go around. Also, the aluminum aft piece for inspection and repair in the tail is good, as is the open rudder post.

One trick I used on the cub was to add silicone on the top of the lower longhorn and shape it to run the water and sand away from the fabric and not get trapped between the longeron and fabric. Works great for planes sticking the tail in the water all the time.

Seems to me that you can minimize if not eliminate exterior airframe problems by a thorough washdown afterward.
Your concern seems to be sand from your shoes trickling around in the airplane.
Why not just bring an extra pair of shoes, and put the sandy ones in a plastic garbage bag when climbing aboard for departure?
Shake out your beach blanket or whatever real well, maybe bag them also.

A little dip will do ya' when on floats. Swing the waders through the water before climbing in. Salt water? Big deal is dried dirt in cockpit slowly clogging up the two instrument vacuum filters and eventually working the carbon vanes in the pump to failure.

Gary