When I removed the flaps from 37J I noticed two of the six aluminum attachment brackets had corrosion. The exfoliation is significant and will likely require replacement of the two brackets. I checked with CPAC, and as expected, they ahve none. My A&P/IA can fabricate them if he knows the aluminum alloy composition. Does anyone know what these are made of, or do you know someone who may have access to the Commander drawings/specs that would indicate the material.

By the way, it looks to me like the plastic bracket fairings that slide onto the brackets may have contributed to the corrosion. They appear to have trapped moisture against the metal bracket. I probably won't put them back on the brackets when they're reassembled.

Andrew Tate
N1037J