_"E.P.A. Takes Step to Cut Emissions From Planes"_
"The Obama administration said on Wednesday that it would take the first step toward regulating greenhouse gas emissions from airplanes, but it acknowledged it would most likely take years before stringent standards are enacted."
http://www.nytimes.com/2015/06/11/business/energy-environment/epa-says-it-will-set-rules-for-airplane-emissions.html
In other words on the engines you need to stay in the air. After engine manufacturers already naturally go to the ends of the earth to wring efficiencies out of them to save airliners on fuel costs.
No, don't look at car-alarms, or after-market automotive "sports horns," or heavy equipment back-up alarms, or ultraviolet HID lamps, or after-market exhaust fart cans, or city light pollution, or GMO, or choramine and IQ-lowering fluoride adulterants in municipal water.
No, be sure to promote an international bankers' "Climate Change" joke on the world's population.