The Poppet,air,regulator, cataloged under National Stock Number 1660-01-049-9974, 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 Honeywell International, Inc Div Aerospace-Tucson. 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 4 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 1660-01-049-9974 |
| Primary Part Number | 136621 |
| Item Name | Poppet,air,regulator |
| FSC / FSG | 1660 / 16 — Aircraft Air Conditioning, Heating, and Pressurizing Equipment |
| Manufacturer | Honeywell International, Inc Div Aerospace-Tucson |
| Status | ACTIVE |
| General Characteristics Item Description | 1.680 IN. MAX 1.640 IN. MIN LG,0.640 IN. MAX 0.610 IN. MIN DIA,1 HOLE DRILL THRU TWO WALLS 0.128 IN. MAX 0.124 IN. MIN DIA,1 HOLE DRILL THRU 2 WALLS 0.097 IN. MAX 0.093 IN. MIN DIA,LARGE END THREAD 0.375-24 UNF-3A SPEC MIL-S-7742,SMALL END THREAD 0.250-28 UNF-3A SPEC MIL-S-7742 A |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 136621 PRIMARY | Honeywell International, Inc Div Aerospace-Tucson (USA) |
| Reference | Meaning |
|---|---|
| 135276-1 | 5/9 Secondary reference Cadillac Gage Textron Inc. |
| 136621 | 5/9 Secondary reference Honeywell International Inc. Div Aerospace - Torrance |
NSN 1660-01-049-9974 is a Poppet,air,regulator, manufactured by Honeywell International, Inc Div Aerospace-Tucson, classified under FSC 1660, Aircraft Air Conditioning, Heating, and Pressurizing Equipment. Status: active.
NSN 1660-01-049-9974 has 1 manufacturer part number on file: 136621 (Honeywell International, Inc Div Aerospace-Tucson).
4 possible matches (shared part number, not a government interchangeability claim): 4720-01-478-4190, 5340-01-485-3516, 5999-01-497-3450. Verify interchangeability with system specifications before substitution.
Key specifications for 136621: General Characteristics Item Description: 1.680 IN. MAX 1.640 IN. MIN LG,0.640 IN. MAX 0.610 IN. MIN DIA,1 HOLE DRILL THRU TWO WALLS 0.128 IN. MAX 0.124 IN. MIN DIA,1 HOLE DRILL THRU 2 WALLS 0.097 IN. MAX 0.093 IN. MIN DIA,LARGE END THREAD 0.375-24 UNF-3A SPEC MIL-S-7742,SMALL END THREAD 0.250-28 UNF-3A SPEC MIL-S-7742 A; End Item Identification: ACFT E3A U/O P/N 103594-1-2. 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.
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.