Nosewheel inner tube punctures

by Graham Email

The nose wheel on a Long-EZE is a small-diameter wheel more usually used on taildraggers (which makes sense, since the Long-EZ is essentially a reverse tail-dragger with a castoring nosewheel).
This wheel is part of a more marginal part of the plane; the nosewheel assembly developed when Long-EZEs were using smaller engines and were being built with empty weights around 800 pounds. With the de facto standard powerplant for a Long-EZE these days being the Lycoming O-320, and with the addition of other gizmos to planes, many Long-EZEs weigh in at over 1000 pounds empty. This increases the loadings and stress on the nosegear significantly.
My primary nosewheel is a Gerdes wheel fitted with slick Cheng Shin tire and inner tube (courtesy of Ken Miller). I have a spare Brock nosewheel/bearing assembly fitted with a treaded tire and tube which is carried inside the nose of the plane attached to a bulkhead, for field use if I encounter nosewheel problems away from home. The nosewheel assembly can be swapped in 10-15 minutes in the field.
One issue noticed in the past by owners is that if the tire pressure drops significantly in the nosewheel, the tire can start to rotate on the rim. This abrades the inner tube, and can puncture it.
I had an example of this several years ago. I pulled out the plane, loaded it up, lowered the nosewheel and jumped in. I cycled through the internal pre-flight, fired up the engine, and went to move off.
The plane promptly dived to the right.
I tried again. The plane still wanted to dive to the right.
I suspected a sticking main brake. I pulled the plane back into the hangar, removed the wheelpants, and checked both brakes. No sign of wheel sticking or other brake issues. I replaced the wheelpants, pushed the plane outside, and got in again. Started the engine. Went to move off.
Now the plane dived to the left.
WTF?
Then...I did something rather sensible. I looked through the nosewheel inspection window.
The front tire was flat.
I did not notice this issue when I was about to get in the plane, becaause, with the nose gear extended, there is no weight on the nosewheeel, thus a flat tire will not compress. Once you are in the plane, and a significant portion of your body weight is on the nose gear, a flat tire is easily spotted.
I replaced the nosewheel with the spare (Brock) nosewheel, and went flying.
When I pulled apart the Gerdes wheel and removed the inner tube, I had suffered a classic abrasion puncture of the tube due to the tire rotating on the rim.
With such a small tire, loss of even a small amount of air has a significant impact on tire pressure. After this incident I began monitoring the nosewheel tire pressure every month. I usually find the pressure has dropped by 5-10 pounds in a month, requiring air to be added.
You should plan to monitor the nose tire pressure at least monthly to avoid the tire rotation/inner tube abrasion problem. I also added an item to the checklist to push down on the nose after lowering the gear and look at the nose tire to see if it has lost pressure, before getting into the plane.