Something to look for at Condition Inspection

A couple of days ago I noticed that the plate on top of the air box had what seemed to be a small crack. When I took it off I noticed that all for corners were cracked. There seems to be plenty of clearance between the air box and the cowl so I can't think of an installation reason for this.



I didn't want to replace it with the same and have it crack again so I ordered some 1/8" thick plate and made a thicker one (the old one was 1/16").

There is a chance that others with this setup (Precision Airmotive vertical induction with the Van's air box) should be seeing this too. Inspecting it is worth adding to the list of things to do at the annual.



Luis Luciani
RV8, ~150 Hours

Those cracks show every indication of being vibration-induced fatigue cracks. A fairly large mass (FAB) held on by relatively thin metal. Some builders have fabricated a brace to the FAB to reduce the vibrations.

Normal life limited wear item.

Has your prop been dynamically balanced?

I had the same issue 6 months ago on mine... I was going to do as you did and order up some heavier or different material to make a new plate, but had a heck of a time finding a vendor who would sell such a small piece. I ended up ordering a new mount plate from Vans and figured I'd just plan on replacing it again in another 3-400 hours.

So where'd ya get the new plate stock? Somewhere local in Houston I hope?

jbDC9 said:

I had the same issue 6 months ago on mine... I was going to do as you did and order up some heavier or different material to make a new plate, but had a heck of a time finding a vendor who would sell such a small piece. I ended up ordering a new mount plate from Vans and figured I'd just plan on replacing it again in another 3-400 hours.

So where'd ya get the new plate stock? Somewhere local in Houston I hope?

Click to expand...

Wicks Aircraft will promptly ship as small a piece of stock as you need.

John, I just bought a 12x12x.125 piece from Vans for about $30. I didn't know I could order pieces from Wicks.

Webb, I haven't had my prop balanced but thanks for the suggestion. I am seriously thinking about it.