http://sustainableaviation.org/sas2016/session/1st-annual-honorary-dr-paul-b-maccready-lecture-from-solar-challenger-to-hale-aircraft-doing-more-with-much-less/ Sustainable Aviation Symposium Sun, 25 Feb 2018 08:00:51 +0000 hourly 1 https://wordpress.org/?v=4.8.1