Boom operator station, oxygen cylinders
The yellow objects at the aft end of the cargo compartment are low-pressure gaseous oxygen cylinders.
The opening in the floor provides access to the boom operator's position. The boom operator lies prone, facing aft on the aircraft centerline, and there are left and right positions for observers or instructors to lie prone as well.
Another opening is covered by a grill on the far side of the oxygen cylinders.
Boeing built a total of 820 C-135 variants, of which 732 were delivered as KC-135A aerial refueling aircraft. This aircraft, s/n 55-3139 (c/n 17255) was the 22nd KC-135A produced.
-----
KC-135 Stratotanker (Wikipedia):
en.wikipedia.org/wiki/Boeing_KC-135_Stratotanker
-----
Castle Air Museum:
Boom operator station, oxygen cylinders
The yellow objects at the aft end of the cargo compartment are low-pressure gaseous oxygen cylinders.
The opening in the floor provides access to the boom operator's position. The boom operator lies prone, facing aft on the aircraft centerline, and there are left and right positions for observers or instructors to lie prone as well.
Another opening is covered by a grill on the far side of the oxygen cylinders.
Boeing built a total of 820 C-135 variants, of which 732 were delivered as KC-135A aerial refueling aircraft. This aircraft, s/n 55-3139 (c/n 17255) was the 22nd KC-135A produced.
-----
KC-135 Stratotanker (Wikipedia):
en.wikipedia.org/wiki/Boeing_KC-135_Stratotanker
-----
Castle Air Museum: