Challenger 604 Saddle Tank Corrosion

It has been several years since we’ve observed saddle tank corrosion aboard the CL604; however, we are beginning to see it more often in the field.

Gaining access to the entire top skin panel is an issue when applying the corrosion inhibiting compound, Dynatrol, and the Service Bulletin 604-53-012 does not mention the treatment of the landing below and inboard of the top panel. However, experience has taught us that should be treated as well.

We highly recommend you inspect the application of the Dynatrol and consider applying a second coat. An ideal time to do this is during the incorporation of SB 604-21-009—ACU exhaust duct flange & fuselage skin mating surfaces.