AJ Savage Wing and Fin Fold

 For an overview, see https://thanlont.blogspot.com/2010/03/hell-it-wont-fit-ii.html

To reduce weight, North American eliminated the customary pilot-actuated power folding of the wings (and in this case the fin) in favor of a post-flight installation of hinges and power supply (hydraulic actuator for wing fold and arm-strong for fin fold).

For the wings, an access panel over the inboard side of the wing fold joint was removed. Two hinges were then attached to the wing at the fold joint. A hydraulic actuator was mounted on the rear hinge, which was bolted to the upper wing surface. The pins connecting the inboard and outer wings were then removed to allow the wings to be folded.

Hydraulic power was provided by a hose connected to the aircraft's hydraulic system at the top of the engine nacelle.

When folded, the exposed wing joint looked like this:

Folding the fin required the temporary installation of a long, folding access ladder:

The upper standoff of the ladder hooked into two slots just forward of the horizontal stabilizer (this is the AJ-2 empennage that was retrofitted to AJ-1s):

Next, the actuator had to be attached, the bolts holding the fin on removed, and the hand crank turned to fold the fin (this illustration is the empennage of the original AJ-1):

A view from the front of the final folded configuration (the sailor hugging the tip tank is checking to be sure that it will fit through the hangar door):

AJ Savage Bomb Bay Doors

The new Roden 1/72 AJ-1 Savage kit provides interior detail in the bomb bay and conventional bombs to go in it, but the bomb bay doors are provided as a single piece, providing no view into the bomb bay.

Since the AJ Savage was literally designed around the Mk 4 nuclear bomb (one is provided in the kit), it seems appropriate that its cavernous bomb bay be visible...

Thanks to Jerry Wells, we have illustrations that can be used to convert the single-piece doors to separate ones in their open positions.

There were four separate, fairly thick doors with lightening holes along the sides. The upper door was attached to the fuselage and the lower door by piano hinges.

The doors were interchangeable. In the following illustration, they are partly open. The opening and closing was accomplished by a mechanism (A) between the upper and lower doors combined with an idler strut at both ends of the lower door that was attached to the fuselage bulkhead at either end of the bomb bay.

 The following illustration depicts the position of the actuation links between the upper and lower doors when the doors are closed:

Another view of the idler strut on the forward left hand side with the doors fully open:

The actuator was a very complicated mechanism that converted the longitudinal extension of a hydraulic piston into a rotation of the outboard link of the actuator that resulted in the doors being pulled together. The idler struts at each end of the bomb bay caused the doors to move outboard as they came together.

Note that when the doors are open, the links of the actuator mechanism are visible; they don't appear to extend inboard any farther than the bomb bay opening, however (this is a picture of the Lycoming AJ-2 Savage with the support structure in the bomb bay for the jet engine test rig):

 

The idler struts are more prominent:

 

For an introduction to the Roden kit and links to other posts, see https://tailspintopics.blogspot.com/2022/08/roden-172-north-american-aj-1-savage.html