get those engines modified so they do take unleaded, shit is bad for anyone breathing it
edit: also, I’m not sure I completely buy it. Lead was only picked as an additive because it was the cheapest available. Before it was even picked, there were other economically and mechanically viable alternatives. The commercial aircraft industry switched to a different additive seamlessly once lead was legislated away. The studies about this are abundant and easily found; sounds like some old farts just managed to squeeze by with a bogus excuse that no-one scrutinized.