If the Apache M231 rocket launcher doesn’t register when rockets are loaded, then check the contacts first before troubleshooting further.
Photo by Markus Rauchenberger
This article initially appeared in PS 745 (Dec 14), pp. 25-26 with the title “Rocket Launcher Needs Help”
Repairers, when you load rockets into your AH-64’s M261 rocket launcher, you know something isn’t right if the rockets don’t register.
The first suspect is the launcher’s contacts. Before you go on a major troubleshooting expedition, first try using a stainless-steel brush to clean the firing contacts in the tubes where the rockets won’t register. If the contacts are dirty, the rockets don’t have a good electrical connection. That prevents the launcher from knowing the rocket is loaded.
Sometimes when you clean the launcher tubes with CLP, too much gets applied to the bore brush. If that happens, and the excess CLP isn’t removed or dried up, the fired rocket motors burn the CLP and leave behind a coating on the contacts. When you load the next rockets, they won’t register on the cockpit display panel.
As always, make sure you use a clean bore brush when cleaning the rocket tubes. Don’t use one coated with dirt and carbon. A dirty brush just spreads that stuff around inside the tube. If your brush is dirty, clean it with soap and water and allow it to dry completely before using it again. That way you don’t introduce moisture into the tubes.
Clean tubes with clean bore brush
Another maintenance tip is to leave the igniter arm up for flights when no rockets are loaded. Doing this protects the contacts from the environment.