The Bellows, cataloged under National Stock Number 1660-01-244-1320, is classified within Federal Supply Class 1660 (Aircraft Air Conditioning, Heating, and Pressurizing Equipment) of the Aircraft Components and Accessories group. The manufacturer of record is Triumph Thermal Systems, Llc. Government technical data includes 1 specification, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 1660-01-244-1320 |
| Primary Part Number | U537789 |
| Item Name | Bellows |
| FSC / FSG | 1660 / 16 — Aircraft Air Conditioning, Heating, and Pressurizing Equipment |
| Manufacturer | Triumph Thermal Systems, Llc |
| Status | ACTIVE |
| FSC Application Data | ENVIRONMENTAL CONTROL SYSTEM |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL Q — CCL Item — Commerce Control List |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| U537789 PRIMARY | Triumph Thermal Systems, Llc (USA) |
| Reference | Meaning |
|---|---|
| U537781 | 5/9 Secondary reference Triumph Thermal Systems, Llc |
NSN 1660-01-244-1320 is a Bellows, manufactured by Triumph Thermal Systems, Llc, classified under FSC 1660, Aircraft Air Conditioning, Heating, and Pressurizing Equipment. Status: active.
NSN 1660-01-244-1320 has 1 manufacturer part number on file: U537789 (Triumph Thermal Systems, Llc).
Key specifications for U537789: FSC Application Data: ENVIRONMENTAL CONTROL SYSTEM; End Item Identification: B-1B AIRCRAFT. 1 specification is documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
NSN 1660-01-244-1320 has DEMIL Code Q. Demilitarization may be required before disposal or transfer to non-military entities.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.