NEWS | Aug. 18, 2021

MLRS: PMCS Multiplies Performance

MLRS fires a Guided Multiple Launch Rocket System rocket
Courtesy Photo of PEO Missiles and Space

Dear Editor,
        
While I was reading Pages 36-38 of PS 769 (Dec 16), I noticed some out-of-date information. The lubricant has changed and there’s a new TM number along with a few other things. Is it possible to make these changes with the latest information?

Pablo Merel
AMC Missile LAR
Editor’s note: Consider it done, Pablo. To capture the changes that happened after we published the story you referenced, here’s an update:
        
  • Give the launcher the same attention you give the carrier. Don’t ignore the launcher when performing PMCS. Without exercise, the launcher batteries go dead, the rollers on the booms freeze and the hydraulic fluid turns to gunk. To prevent this, operate the booms and hoist weekly.
            
  • Keep connectors as clean as possible. The slightest amount of dirt inside connectors can cause system faults. Remove outside dirt before disconnecting connectors. Then clean the connectors with electric cleaning compound, NSN 6850-01-371-8048, while they’re disconnected. Or you can use technical isopropyl alcohol, NSN 6810-00-286-5435, if the electric cleaning compound isn’t available. And remember to secure the connector with safety wire if required.
     
  • Grease well, but first get rid of the old grease. As you operate your MLRS in dirty environments, the dirt mixes with the grease and stops lubricating. That wears out boom parts fast, especially gears and the boom motor.

    Before adding new grease, you must get rid of the old grease. Use lubricant cleaner CLP-1, NSN 9150-01-327-9631, to get the old grease out. You’ll find the cleaning instructions in WP 550-15 of IETM 9-1055-647-13&P (Jun 20). Also, make sure to clean the boom forward rollers using WP 550-3 of IETM 9-1055-647-13&P. Finally, make sure to grease the gear teeth.
 
Check gear teeth for grease
Check gear teeth for grease
 
  • Careful with the W19 and W20 cables. If you get in a hurry during reloads and yank on the cables, they can break. Take the time to fully unlock the cable connectors and then pull straight back on the connectors when disconnecting. And don’t pull on the cables! That breaks wiring.

    The umbilical adapters were added to the ends of the W19 and W20 cables to protect the cables from heavy wear and damage. The cables are very difficult to replace and your unit maintenance budget takes a huge hit when they have to be replaced. See WP 0367 of IETM 9-1055-647-13&P for the full details.
Fully unlock W19 and W20 cables before removing them
Fully unlock W19 and W20 cables before removing them
  
  • Careful with cables while traversing. If the cables aren’t following the grooves in the cable wrap, they get tangled and then you’ve got a real mess. Make sure someone watches the cables as you traverse the launcher. Never disregard the panel lights and warning alarms because they let you know something is wrong. 
     
  • Don’t forget hydraulic fluid. If the fluid gets too low, the launcher will move erratically or not at all. So don’t forget to check the level. All it takes is a glance at the sight glass. Remember to keep the sight glass clean for easy reading. Let the repairer know if the level doesn’t read GOOD. Whenever the launcher moves strangely, check the hydraulic fluid level.
     
Check hydraulic fluid during PMCS
Check hydraulic fluid during PMCS