NEWS | Oct. 22, 2020

Apache: Sustaining IHADSS Equipment

Armament maintainers, if you’re sustaining AH-64Ds that are not equipped with Integrated Helmet and Display Sighting System (IHADSS)-21s, you should only order the legacy IHADSS line replaceable unit (LRU) NSNs. Make sure you order these parts to replace LRUs:
  • Display electric unit (DEU), NSN 1270-01-183-0518
  • Display adjustment panel (DAP), NSN 1270-01-211-6346
  • Helmet display unit (HDU), NSN 1270-01-291-9334
Don't upgrade legacy IHADSS to IHADSS-21 by requisitioning the IHADSS-21 LRUs, which are:
  • Electronic enhanced display unit (EEDU), NSN 1270-01-553-1147
  • Display driver unit (DDU), NSN 1270-01-553-1145
  • Improved helmet display unit (IHDU), NSN 1270-01-553-1146

Don’t order IHADSS-21 NSNs to sustain IHADSS
You probably think it makes sense to upgrade all Apaches to IHADSS-21. Then there wouldn’t be a mix of legacy IHADSS and IHADSS-21 AH-64D Apaches. However, here are some reasons for units not to upgrade all aircraft.
  1. Class IX cost is a factor.  FED LOG pricing for the IHADSS-21 upgrade for all 3 NSNs will cost $126,264, which is far greater than changing out one of the individual legacy IHADSS LRU’s components as they fail; the components won’t likely fail all at one time, and the display adjustment panel costs $27,000, the helmet display unit is $11,000, and the display electronic unit price is $51,000. So don't count on exchange credit from the legacy IHADSS components to make up for the upgrade price.
  2. The IHADSS-21 upgrade is included with the AH-64E aircraft fielding. Keep in mind that AH-64E fielding is ongoing and soon they’ll become the majority of the fleet.  So receipt of the AH-64E could be thought of as a free issue of IHADSS-21 to units.
  3. If your unit does upgrade to IHADSS-21, it’s competing with other IHADSS-21 AH-64Ds and AH-64Es for the same assets when parts become unserviceable. Right now the stock availability is better with the legacy IHADSS.
Got questions? Contact equipment specialist David Jirak, item manager Brittney Affholter or weapon system manager Tracy Hernandez by email: