Is under the cockpit used to access avionics on the ground or something like that ?
$\begingroup$ I feel like we have seen one of these before... or was that for the DC4? $\endgroup$– dalearnNov 11, 2017 at 21:06
It seems to be an access door for the pilots, judging from this photo. Not a super easy entrance, the door in the back is a bit lower down.
19$\begingroup$ As the caption indicates, it allowed access to the flight deck when the cabin was packed with cargo. My dad, an A&P who spent 20+ years working on DC-3s, referred to it as the "meat grinder door" -- not to be used with the left engine running. $\endgroup$– GerryNov 11, 2017 at 13:46
In 1974 I was hauling checks in the Northeast and we routinely used this door to board the plane. When it was frozen shut or had a latch problem, which happened, then we crawled around the sacks and cargo netting. If everything was working we used the front door. Schedules were tight and we were normally getting our clearances while the bags were getting loaded and offloaded.