RV-12: Engine Mounting Cap Screws Inspection
This is a FLIGHT CRITICAL situation that IMHO requires inspection and corrective action before next flight.
Flying RV-12's owners should take immediate action to check the 4 engine ring mount socket head cap screws before next flight. Many bolts have vibrated loose, and several have fallen out!
During a recent inspection I found the two bottom socket head cap screws that hold the engine mount ring to the engine had worked themselves loose. I pulled them out, inspected the threads, added blue loctite, and retorqed to 26 ft pounds, and I didn't think too much about it until Tony T contacted several of us last week with the same issue. Then the flood gates opened. Nearly everyone Marty S & I talked to flying the RV-12 has had the engine mounting cap screws come loose around 100 hours.
The top two engine mount cap screws have also been reported loose also so all 4 need to be checked. The bottom two are easy access. The top right needs to have the carb & carb socket and drip pan removed. The upper left is inaccessible and the cooling shroud will need to be modified. John Bender was able to get at it by modifying the cooling shroud.
The plans do not call out blue loctite on these bolts and IMHO there should be.
RV-7 : In the hangar
RV-10 : In the hangar
RV-12 : Built and sold
RV-44 : 4 place helicopter on order.
Last edited by Geico266 : 12-02-2010 at 01:23 PM.