Thomas McIntosh

This is the second rulemaking in three years that I am aware of concerning ECi cylinders (the other one resulted in an AD). The cost estimates for this proposed AD are only for replacement of defective cylinders. The estimates do NOT include the costs to the aircraft owner for repetitive inspections at fifty hour intervals, nor for the loss of continued use past TBO for a privately used aircraft that is permitted so long as the cylinder is deemed airworthy (this proposed AD mandates removal at TBO hours regardless of condition.) Adding in these items will add a huge sum to the overall compliance costs. If there truly is a widespread problem with the Titan cylinders (the proposed AD indicates a forecast of 18 percent of the cylinders in use), then ECi should provide warranty replacement for all of the affected cylinders, not just those that are found to have already failed.