I think this is the record for the longest battery only electric RC airplane flight, excluding the use of fuel, solar cells, or slope soaring. I am happy to answer your questions in the comments section. There is more detailed build info here:
?t=260 10 hours and 45 minutes 340 miles or 547km across the ground Phoenix 2400 Matek F405 Wing with Arduplane code 12x12 APC propeller Racerstar 4108 600KV motor Turnigy Plush-32 30A ESC (LVC disabled) 50,000 mAh 4s Li-Ion battery pack that I made with LG M50 cells Here are my STL files for 3D printing: https://www.thingiverse.com/thing:4564628/files 0:00 Intro 0:51 Assembly 2:06 Arming 3:05 Launch 4:43 Condensed Flight 7:04 Landing 7:54 Touch Down 8:46 Airplane Tour 9:50 Summary