National Stock Number
1660-01-399-8257
National Stock Number (NSN) 1660-01-399-8257, or NIIN 013998257, (duct assembly,air conditioning-heating,aircraft) was assigned December 6, 1994 in the Federal Logistics Information System (FLIS). NIIN 013998257 was cancelled on May 1, 2010, with a cancelled status of "Item is Cancelled - Inactive." There is no known replacement specified for this stock number. This NSN does not replace any other NSNs.
There are 2 manufacturer part numbers associated with this NSN. One of those part number(s) are considered obsolete. The manufacturer part numbers were originally supplied by 2 suppliers. Today, 2 suppliers are listed as Active suppliers for this NSN. Of the active suppliers, only one supplier is deemed design controlled or valid supply parts.
This part number has not been procured by the US Government in over 5 years.
This NSN is assigned to Item Name Code (INC) 32351. [A HOLLOW BODY USED TO TRANSPORT AIR TO VARIOUS PARTS OF THE AIRCRAFT FOR THE PURPOSE OF HEATING, COOLING, PRESSURIZING, DE-ICING, AND THE LIKE. IT MAY INCLUDE FLANGE(S), BRACKET(S), AND THE LIKE FOR MOUNTING PURPOSES. EXCLUDES:PIPES USED IN AIRCRAFT EXHAUST SYSTEMS AND PIPES USED IN NON-AIRCRAFT APPLICATIONS. EXCLUDES:PIPE, EXHAUST AND PIPE, AIR CONDITIONING-HEATING.]. This item does not have a nuclear hardened feature or any other critical feature such as tolerance, fit restriction or application. There is no data in the HMIRS and the NSN is in an FSC not generally suspected of containing hazardous materials. NSN 1660013998257 does not contain precious metals.
This information was last updated on Aug 01, 2025.