23 November 2025: With the help of Ed Barthelmes, I've retitled and revised with corrections and additions
The AD Skyraider had three different outboard wing pylons. The first was a simple rocket launcher:
The second was a direct substitute for the rocket launcher that allowed for up to 260-lb bombs and other stores to be loaded on it. The Mk 55 Bomb Rack was about 13 inches long and included sway braces.
Note that the Mk 55 utilized the single-lug option to attach the bomb.
The AERO* 14A/B was subsequently developed that could be loaded with either a bomb (up to 500-lbs) or a rocket:
This picture illustrates the difference in the size of the Mk 55 and the AERO 14:
For the spacing of the AD's outboard wing pylons and details of the center line and inboard wing pylons, see https://tailhooktopics.blogspot.com/2015/07/douglas-ad-1-skyraider-pylons.html
*Note that strictly speaking, AERO should be all capital letters, since it is an acronym for Aircraft Equipment Reference Ordinal...