Interesting comparison with the "second-pilot" position on the similar narrow layout Martin B-10 /export W139 aircraft. The relief pilot was located in the dorsal-gun position, with rudimentary instruments. His task was to take over the controls to spell the pilot during longer patrols, and to take over if the pilot was hit by enemy action. There was no intent to land the Martin bomber from the rear seat, just to get it to a safer location for the crew to bale out. The Dutch East Indies crew were forced to utilise this feature on a number of missions in 1941/42. The Dutch actually referred to the crew member as the "gunner-pilot" if suitably qualified.
Hello Alex, I seem to be following you around the past few days. Nothing intended... purely coincidental... not stalking...
...geoff