An official website of the United States government
Here's how you know
A .mil website belongs to an official U.S. Department of Defense organization in the United States.
A lock (lock ) or https:// means you’ve safely connected to the .mil website. Share sensitive information only on official, secure websites.

Home : Articles
Would you stake your life, right now, on the condition of your equipment?
Articles
NEWS | July 6, 2020

AH-64E: Keep Moisture Out of NIU

A Soldier conducts maintenance on parts of an AH-64E Apache helicopter tail.
Photo by Spc. Alexander Holmes
 
The AH-64E Apache’s nitrogen inerting unit (NIU), NSN 1560-01-587-1028, is designed to reduce oxygen in the aircraft’s fuel cells to prevent combustion. That enhances its crashworthiness and ballistic tolerance.

But there’ve been some problems with the NIU. After analyzing some 785 units returned for upgrade, overhaul or repair, 31 percent were returned because of moisture damage. 

The NIU has a small amount of zeolite material to absorb atmospheric moisture from aircraft operation, but it isn’t designed to absorb moisture from direct sources, such as a power washer. If this kind of moisture gets inside the NIU, it can cause the NIU to immediately or prematurely fail for these reasons:
 
  • Moisture causes the motor and fan inside the NIU to corrode or rust, possibly causing the motor and fan to stop completely or produce a rattling noise.
     
  • Moisture deteriorates the zeolite material. It initially clumps, then breaks down into a fine dust that escapes the unit, causing a dusting effect in the aircraft.
     
  • Moisture in the NIU clogs the orifice in the pressure reducer, leading to failure.
To prevent moisture and other damage to the NIU, follow these steps if removing the NIU isn’t possible:

      1.  When cleaning and washing the aircraft ammunition bay, cover the NIU with barrier material to keep water out.
 
Apache NIU
Cover NIU to prevent water intrusion when cleaning
or washing ammunition bay

      2.   Cap all NIU openings with protective material when you’re cleaning or performing aircraft maintenance.

      3.  During refueling, make sure fuel doesn’t spray onto the NIU.

      4.  When ready for storage, keep the NIU in its original shipping container, wrapped in plastic, and with all caps in place.
Want to get better search results faster? 
Click the link below to access our "how to" guide
.
After entering a keyword, you must hit or click the Search bar/box below for the function to work.
Simply hitting Return won't yield results.
LOGSA Links/URLs
Note about links to archive articles

If you come across a link to a pre-2014 PS Magazine issue or article that uses LOGSA in the web address (URL), use this link instead:
 
For issues/articles from 2014 and after, click on the Archive/Index tab in the top menu of this website.

BE ADVISED: With the migration to Army365, emails in older articles may still reflect an @mail.mil address. To update, change the domain to @army.mil