Cool stuff.
For reference here is a Sikorsky GA of the S-61N, note the different tail pylon of the L and N,
the shortened models flying around, VHI, HeliJet, Hayes etc., have that pylon:
I also have a stations/waterlines drawing along with details of the pylon, L model fixed gear,
bulkheads,etc., all copied from the structural repair manual.
Another drawing I need to scan is a GA of the Shortsky conversion I made with
old school cut-n-paste + Xerox methods.
A couple technical things, from sta.32 to sta.110 under the cockpit floor is the E & E bay, which
is stuffed full of avionics. Behind the flight deck, on the right side, is the control closet with the
rotor control servos and AFCS electronics.
And some trivia on the logging machines, the cockpit side windows are bulged out so the pilot
can look down at the ground and some machines have a small auxiliary instrument panel mounted
on the left side in the pilot's line of vision so the engines can be monitored while looking at the
ground. They are also primarily flown from the left seat, rather than the right, when logging.