Presumably, the base sales would be for replacement. You don't need increasing sales to handle replacement rate. I'd expect ~40% more device sales roughly means

Presumably, the base sales would be for replacement. You don't need increasing sales to handle replacement rate. I'd expect ~40% more device sales roughly means 40% more devices on planes, which means ~40% more device incidents on planes. Though, that's not to say it's not worrying, just that it's not exactly a surprising increase.