Somehow society is stuck between the information age and the stupid age.
https://www.scientificamerican.com/article/lead-in-aviation-...
Somehow society is stuck between the information age and the stupid age.
https://www.scientificamerican.com/article/lead-in-aviation-...
"Current aircraft engines feature valve gear components which are designed for compatibility with the leaded ASTM D910 fuels. In such fuels, the lead acts as a lubricant, coating the contact areas between the valve, guide, and seat. The use of unleaded auto fuels with engines designed for leaded fuels can result in excessive exhaust valve seat wear due to the lack of lead. The result can be remarkable, with cylinder performance deteriorating to unacceptable levels in under 10 hours."
https://web.archive.org/web/20120413123438/http://www.tcmlin...
Also lead is an anti-knock agent so it is used to get to the very high octane ratings in Avgas.
And it seems the problem may be solved soon!
"By May 2012, the US Federal Aviation Administration (FAA Unleaded Avgas Transition rulemaking committee) had put together a plan in conjunction with industry to replace leaded avgas with an unleaded alternative within 11 years. Given the progress already made on 100SF and G100UL, the replacement time might be shorter than that 2023 estimate."
So still not great, but a bit of googling shows that leaded avgas is less than 2% of total civilian aviation fuel in the U.S.: https://www.faa.gov/data_research/aviation/aerospace_forecas...
Yes, laziness, ignorance, stupidity, incompetence, malice, etc, are all possibly valid answers to "Why?". But accepting such answers without scrutiny when another answer may be closer to the truth is a bad habit, IMO. If you were to come into a legacy codebase at work and assume that the previous authors incompetent idiots, you'd probably be less productive than if you assumed that the previous authors had problems to solve and chose the best option available to them given the constraints at the time. Keeping in mind past and current goals, and past and current constraints is probably going to get you further than, "This is bad! Change it!"