B-17 1875mm 72″ Bomber Bomb Bay Posted on May 8, 2015May 16, 2018 by adm1n_rc This is a Sonic 1875mm wing span (6′) B-17. Sometimes called a HK B-17 that has the center section modified with a custom bomb bay to hold 5 Adam Bombs. Two 12.5 gram servos control the bomb bay doors. These bombs were filled with Talcum powder.