Which adapter is used to mount the LAU-128 rail launcher to the sides of pylons on the F-15C/D/E?

• A. ADU-551 adapter
• B. ADU-553 adapter
• C. ADU-552 adapter
• D. ADU-550 adapter

Answer: (C)

Mounting a rail launcher like the LAU-128 to a pylon isn’t a direct bolt-on; it uses a dedicated interface called an adapter to match the launcher to the aircraft’s mounting geometry. Each pylon position and launcher combination has a specific adapter that provides the correct bolt pattern, spacing, and clearance so the launcher sits properly in line with the aircraft’s axis and avoids interference with airframe structures.

For the F-15C/D/E side stations, the adapter designed to fit the LAU-128 is the one that provides the exact side-mount geometry the launcher needs. That particular adapter ensures the LAU-128 aligns correctly with the pylon, maintains proper clearance to neighboring components, and provides the necessary mounting and electrical interfaces. The other adapters are used for different pylons or different launchers and would not fit or align correctly in the side-mount position, which is why this one is the correct choice for the F-15’s side pylons.