I noticed some stuff streaking out of my engine. Was getting worried. I’m like… OMG what the heck is happening under the cowl. I doubled my oil checking frequency but, weirdly enough, consumption is at normal levels. Yet I have these long black streaks coming out of my engine compartment.
I’m about ready to find time to pull the cowl off and have a look when my A&P, Tom, shows up at the hangar next door. We chat and I show him the streaks with a worried look. He asks “Have you been flying in the rain?” I’ve been getting in some light IMC lately so I puff out my chest and proudly proclaim “YES I HAVE!”.
He smiles, seeing the IMC newbie that I am, and explains what I’m seeing is aluminum dust being carried away by rain coming through the seams. Tom goes on to explain that when the plane is manufactured, all seams that rub like the cowling and the oil filler door, have special tape placed on the edges. Eventually that tape either dries up and falls off or wears off. The parts rub and create a fine dust. Then when you fly through the rain, it washes that dust out and leaves a aluminum residue streak.
I can stop this streaking if I simply re-tape the seams. Good ol’ masking tape will work if I choose.
Tom then asked if I had any “smoking rivets”. Sure do! Same thing here. They’re rivets which are working themselves loose – vibrating in the holes. Nothing structural to worry about, but eventually they’ll need to be replaced.
So, I was psyched and relieved that nothing was wrong with my engine. In fact, now instead of being worried, I’m actually proud of my dark streaks. I consider them badges of honor from flying in IMC. Cool!!