sensors Mode-S transponder
A22D9F
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N23994 · BOEING 787-9 Dreamliner · operated by UNITED AIRLINES INC
- Hex
- A22D9F
- Octal
- 50426637
- Decimal
- 10,628,511
- Country
- US
- Tail
- N23994
- Type
- B789
- Flights observed
- 212
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 4h ago
Last known position
Country allocation
The ICAO 24-bit address A22D9F falls within the block assigned to United States (US) by ICAO Annex 10, Volume III. Every aircraft registered in United States receives a permanent address from this block at the time of registration; the address stays with the airframe even if the aircraft is re-registered to a different operator within the country.
Callsign history 20 distinct
| Callsign | Airline | Flights | Last seen |
|---|---|---|---|
| UAL152 | United Airlines | 15 | 2026-06-21 |
| UAL772 | - | 12 | 2026-06-25 |
| UAL199 | United Airlines | 12 | 2026-06-23 |
| UAL821 | United Airlines | 10 | 2026-05-22 |
| UAL198 | - | 10 | 2026-06-23 |
| UAL153 | United Airlines | 10 | 2026-06-22 |
| UAL771 | - | 8 | 2026-06-24 |
| UAL820 | United Airlines | 7 | 2026-05-22 |
| UAL63 | - | 6 | 2026-07-07 |
| UAL62 | - | 6 | 2026-07-06 |
| UAL6 | - | 5 | 2026-07-05 |
| UAL1855 | - | 5 | 2026-07-08 |
| UAL79 | United Airlines | 4 | 2026-04-18 |
| UAL7 | - | 4 | 2026-07-07 |
| UAL60 | United Airlines | 4 | 2026-06-13 |
| UAL33 | - | 4 | 2026-07-08 |
| UAL187 | - | 4 | 2026-07-13 |
| UAL178 | United Airlines | 4 | 2026-04-26 |
| UAL82 | - | 3 | 2026-06-26 |
| UAL713 | United Airlines | 3 | 2026-06-14 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-13 | UAL187 | - | Jul 13, 20:05 UTC | Jul 13, 23:25 UTC | 3h 20m |
| 2026-07-13 | UAL187 | JNB → EWR | Jul 13, 20:19 UTC | Jul 14, 11:14 UTC | 14h 55m |
| 2026-07-13 | UAL188 | - | Jul 13, 02:25 UTC | Jul 13, 16:35 UTC | 14h 10m |
| 2026-07-11 | UAL187 | - | Jul 11, 20:20 UTC | Jul 12, 11:05 UTC | 14h 45m |
| 2026-07-11 | UAL188 | - | Jul 11, 02:15 UTC | Jul 11, 16:20 UTC | 14h 5m |
| 2026-07-10 | UAL123 | LHR → EWR | Jul 10, 07:02 UTC | Jul 10, 14:20 UTC | 7h 18m |
| 2026-07-10 | UAL123 | LHR → EWR | Jul 10, 07:15 UTC | Jul 10, 14:25 UTC | 7h 10m |
| 2026-07-09 | UAL122 | EWR → LHR | Jul 9, 13:55 UTC | Jul 9, 20:05 UTC | 6h 10m |
| 2026-07-08 | UAL1855 | - | Jul 8, 21:45 UTC | Jul 9, 02:25 UTC | 4h 40m |
| 2026-07-08 | UAL33 | - | Jul 8, 08:05 UTC | Jul 8, 17:45 UTC | 9h 40m |
| 2026-07-08 | UAL33 | NRT → LAX | Jul 8, 08:05 UTC | Jul 8, 17:31 UTC | 9h 26m |
| 2026-07-07 | UAL7 | - | Jul 7, 15:50 UTC | Jul 8, 04:45 UTC | 12h 55m |
| 2026-07-07 | UAL63 | - | Jul 7, 01:15 UTC | Jul 7, 01:45 UTC | 30m |
| 2026-07-07 | UAL63 | GRU → IAH | Jul 7, 01:11 UTC | Jul 7, 10:24 UTC | 9h 13m |
| 2026-07-06 | UAL62 | - | Jul 6, 00:05 UTC | Jul 6, 01:45 UTC | 1h 40m |
| 2026-07-06 | UAL62 | IAH → GRU | Jul 6, 00:03 UTC | Jul 6, 09:08 UTC | 9h 5m |
| 2026-07-05 | UAL6 | - | Jul 5, 08:30 UTC | Jul 5, 19:50 UTC | 11h 20m |
| 2026-07-04 | UAL32 | LAX → NRT | Jul 4, 18:15 UTC | Jul 5, 04:45 UTC | 10h 30m |
| 2026-07-04 | UAL32 | - | Jul 4, 18:15 UTC | Jul 5, 04:45 UTC | 10h 30m |
| 2026-07-04 | UAL842 | - | Jul 4, 00:00 UTC | Jul 4, 13:00 UTC | 13h 0m |
| 2026-07-03 | UAL863 | SFO → SYD | Jul 3, 07:05 UTC | Jul 3, 21:50 UTC | 14h 45m |
| 2026-07-02 | UAL949 | - | Jul 2, 12:30 UTC | Jul 2, 22:35 UTC | 10h 5m |
| 2026-07-02 | UAL948 | SFO → LHR | Jul 2, 00:15 UTC | Jul 2, 09:45 UTC | 9h 30m |
| 2026-07-02 | UAL948 | SFO → LHR | Jul 2, 00:14 UTC | Jul 2, 09:39 UTC | 9h 25m |
| 2026-06-28 | UAL1757 | - | Jun 28, 22:49 UTC | Jun 29, 03:49 UTC | 5h 0m |
| 2026-06-28 | UAL1849 | MCO → EWR | Jun 28, 15:24 UTC | Jun 28, 19:44 UTC | 4h 20m |
| 2026-06-27 | UAL1227 | - | Jun 27, 17:49 UTC | Jun 27, 23:19 UTC | 5h 30m |
| 2026-06-26 | UAL83 | DEL → EWR | Jun 26, 21:15 UTC | Jun 27, 06:50 UTC | 9h 35m |
| 2026-06-26 | UAL82 | EWR → DEL | Jun 26, 03:57 UTC | Jun 26, 17:08 UTC | 13h 11m |
| 2026-06-26 | UAL82 | - | Jun 26, 03:45 UTC | Jun 26, 05:19 UTC | 1h 35m |
| 2026-06-25 | UAL1855 | - | Jun 25, 20:49 UTC | Jun 26, 01:39 UTC | 4h 50m |
| 2026-06-25 | UAL772 | - | Jun 25, 05:29 UTC | Jun 25, 07:15 UTC | 1h 45m |
| 2026-06-25 | UAL772 | PEK → LAX | Jun 25, 04:29 UTC | Jun 25, 15:59 UTC | 11h 30m |
| 2026-06-25 | UAL772 | PEK → LAX | Jun 25, 04:29 UTC | Jun 25, 16:01 UTC | 11h 32m |
| 2026-06-24 | UAL771 | - | Jun 24, 07:24 UTC | Jun 24, 19:55 UTC | 12h 30m |
| 2026-06-24 | UAL771 | LAX → PEK | Jun 24, 06:54 UTC | Jun 24, 20:54 UTC | 14h 0m |
| 2026-06-23 | UAL199 | PVG → LAX | Jun 23, 06:24 UTC | Jun 23, 23:24 UTC | 17h 0m |
| 2026-06-23 | UAL199 | PVG → LAX | Jun 23, 01:50 UTC | Jun 23, 23:24 UTC | 21h 35m |
| 2026-06-23 | UAL198 | - | Jun 23, 00:39 UTC | Jun 23, 23:24 UTC | 22h 45m |
| 2026-06-22 | UAL198 | - | Jun 22, 20:39 UTC | Jun 23, 14:44 UTC | 18h 5m |
| 2026-06-22 | UAL153 | HKG → LAX | Jun 22, 05:08 UTC | Jun 22, 17:10 UTC | 12h 2m |
| 2026-06-22 | UAL153 | HKG → LAX | Jun 22, 04:54 UTC | Jun 22, 17:20 UTC | 12h 25m |
| 2026-06-22 | UAL153 | HKG → LAX | Jun 22, 02:10 UTC | Jun 22, 02:34 UTC | 25m |
| 2026-06-22 | UAL153 | HKG → LAX | Jun 22, 00:19 UTC | Jun 22, 02:29 UTC | 2h 10m |
| 2026-06-21 | UAL152 | LAX → HKG | Jun 21, 13:04 UTC | Jun 21, 13:20 UTC | 15m |
| 2026-06-21 | UAL152 | LAX → HKG | Jun 21, 12:49 UTC | Jun 21, 14:57 UTC | 2h 8m |
| 2026-06-21 | UAL152 | LAX → HKG | Jun 21, 10:25 UTC | Jun 21, 10:44 UTC | 20m |
| 2026-06-20 | UAL152 | LAX → HKG | Jun 20, 20:14 UTC | Jun 21, 09:55 UTC | 13h 40m |
| 2026-06-20 | UAL772 | - | Jun 20, 05:24 UTC | Jun 20, 16:09 UTC | 10h 45m |
| 2026-06-20 | UAL772 | - | Jun 20, 04:29 UTC | Jun 20, 04:39 UTC | 10m |
About Mode-S
A Mode-S transponder code (also called an "ICAO 24-bit address" or "hex code") is a 6-character hexadecimal identifier permanently assigned to an aircraft when it's first registered. Unlike callsigns (which change with each flight) or registrations (which can change if an aircraft is sold internationally), the Mode-S address stays with the airframe for the life of the aircraft in that country.
Every ADS-B transmission from an aircraft includes its Mode-S address, making it the most reliable way to identify a specific airframe. Flight-tracking services like Apparatus use the Mode-S address as the primary key for tying position broadcasts, callsigns, and ownership records together.
Prefer a tail-number view? See the N23994 page for operator, model, and routing details .