L-188 From United States of America, joined Jul 1999, 29513 posts, RR: 59 Reply 2, posted (12 years 1 month 1 week 5 days 7 hours ago) and read 892 times:
That top aircraft appears to be equipted with an aft integral airstair. There is a handle for it but it is on the bottom of the fuselauge where ground personel can use it to access the aircraft. Notice how much larger this door is compared to the aft door on the -200 in the other photograph. The upper stage of stairs are located on the door which folds down and there are two more sections that fold down to form the airstair.
When I was working for Alaska Airlines all of their combi 727-200's save for one had an airstair mounted at the rear door.