sensors Mode-S transponder
AAC8A4
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N794UA · BOEING 777-200 · operated by UNITED AIRLINES INC
- Hex
- AAC8A4
- Octal
- 52544244
- Decimal
- 11,192,484
- Country
- US
- Tail
- N794UA
- Type
- B772
- Flights observed
- 223
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- Jul 24, 03:50 UTC
Current position
Country allocation
The ICAO 24-bit address AAC8A4 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 |
|---|---|---|---|
| UAL852 | - | 11 | 2026-06-25 |
| UAL195 | - | 10 | 2026-07-22 |
| UAL949 | United Airlines | 9 | 2026-06-12 |
| UAL853 | - | 9 | 2026-06-24 |
| UAL46 | United Airlines | 9 | 2026-06-10 |
| UAL673 | - | 8 | 2026-07-13 |
| UAL35 | - | 8 | 2026-06-14 |
| UAL160 | United Airlines | 8 | 2026-07-20 |
| UAL819 | - | 7 | 2026-07-09 |
| UAL672 | - | 7 | 2026-07-13 |
| UAL34 | - | 7 | 2026-06-15 |
| UAL102 | - | 7 | 2026-07-11 |
| UAL990 | - | 6 | 2026-07-01 |
| UAL968 | - | 6 | 2026-06-15 |
| UAL889 | - | 6 | 2026-07-18 |
| UAL818 | - | 6 | 2026-07-10 |
| UAL47 | United Airlines | 6 | 2026-06-11 |
| UAL194 | United Airlines | 6 | 2026-07-19 |
| UAL969 | - | 5 | 2026-06-16 |
| UAL939 | United Airlines | 5 | 2026-04-18 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-23 | UAL506 | MSN → DEN | Jul 23, 15:25 UTC | Jul 23, 18:30 UTC | 3h 5m |
| 2026-07-23 | UAL506 | MSN → DEN | Jul 23, 14:57 UTC | Jul 24, 03:37 UTC | 12h 40m |
| 2026-07-23 | UAL507 | DEN → LGA | Jul 23, 02:05 UTC | Jul 23, 12:55 UTC | 10h 50m |
| 2026-07-22 | UAL195 | MUC → SFO | Jul 22, 10:02 UTC | Jul 22, 21:19 UTC | 11h 17m |
| 2026-07-21 | UAL195 | - | Jul 21, 23:05 UTC | Jul 22, 21:30 UTC | 22h 25m |
| 2026-07-21 | UAL195 | - | Jul 21, 22:15 UTC | Jul 22, 21:00 UTC | 22h 45m |
| 2026-07-20 | UAL160 | MUC → IAH | Jul 20, 10:45 UTC | Jul 20, 21:10 UTC | 10h 25m |
| 2026-07-20 | UAL160 | MUC → IAH | Jul 20, 10:49 UTC | Jul 20, 21:03 UTC | 10h 14m |
| 2026-07-19 | UAL194 | SFO → MUC | Jul 19, 21:25 UTC | Jul 20, 07:40 UTC | 10h 15m |
| 2026-07-18 | UAL889 | - | Jul 18, 10:35 UTC | Jul 18, 21:15 UTC | 10h 40m |
| 2026-07-18 | UAL889 | PEK → SFO | Jul 18, 09:51 UTC | Jul 18, 21:04 UTC | 11h 13m |
| 2026-07-17 | UAL888 | SFO → PEK | Jul 17, 18:25 UTC | Jul 18, 07:06 UTC | 12h 41m |
| 2026-07-17 | UAL888 | - | Jul 17, 18:40 UTC | Jul 18, 05:55 UTC | 11h 16m |
| 2026-07-17 | UAL3934 | FLL → ORD | Jul 17, 03:30 UTC | Jul 17, 13:15 UTC | 9h 45m |
| 2026-07-16 | UAL131 | SFO → HND | Jul 16, 07:20 UTC | Jul 16, 17:10 UTC | 9h 50m |
| 2026-07-15 | UAL45 | ZRH → SFO | Jul 15, 12:02 UTC | Jul 16, 00:16 UTC | 12h 14m |
| 2026-07-15 | UAL45 | - | Jul 15, 12:45 UTC | Jul 15, 14:40 UTC | 1h 55m |
| 2026-07-14 | UAL44 | SFO → ZRH | Jul 14, 23:10 UTC | Jul 15, 09:40 UTC | 10h 30m |
| 2026-07-13 | UAL673 | - | Jul 13, 14:35 UTC | Jul 14, 02:20 UTC | 11h 45m |
| 2026-07-13 | UAL672 | SFO → BCN | Jul 13, 01:15 UTC | Jul 13, 12:00 UTC | 10h 45m |
| 2026-07-12 | UAL195 | - | Jul 12, 10:20 UTC | Jul 12, 21:50 UTC | 11h 30m |
| 2026-07-11 | UAL102 | - | Jul 11, 21:55 UTC | Jul 12, 01:55 UTC | 4h 0m |
| 2026-07-11 | UAL102 | IAH → MUC | Jul 11, 22:02 UTC | Jul 12, 07:53 UTC | 9h 51m |
| 2026-07-10 | UAL818 | - | Jul 10, 00:15 UTC | Jul 10, 10:05 UTC | 9h 50m |
| 2026-07-09 | UAL819 | - | Jul 9, 01:55 UTC | Jul 9, 07:30 UTC | 5h 35m |
| 2026-07-09 | UAL819 | IAH → EZE | Jul 9, 02:06 UTC | Jul 9, 11:07 UTC | 9h 1m |
| 2026-07-08 | UAL160 | - | Jul 8, 10:30 UTC | Jul 8, 21:05 UTC | 10h 35m |
| 2026-07-07 | UAL194 | SFO → MUC | Jul 7, 21:35 UTC | Jul 8, 07:55 UTC | 10h 20m |
| 2026-07-06 | UAL506 | - | Jul 6, 14:00 UTC | Jul 7, 02:15 UTC | 12h 15m |
| 2026-07-06 | UAL507 | - | Jul 6, 00:30 UTC | Jul 6, 09:00 UTC | 8h 30m |
| 2026-07-06 | UAL507 | SFO → FCO | Jul 6, 00:19 UTC | Jul 6, 11:41 UTC | 11h 22m |
| 2026-07-05 | UAL195 | MUC → SFO | Jul 5, 10:10 UTC | Jul 5, 16:00 UTC | 5h 50m |
| 2026-07-05 | UAL195 | MUC → SFO | Jul 5, 10:10 UTC | Jul 5, 21:31 UTC | 11h 21m |
| 2026-07-05 | UAL195 | MUC → SFO | Jul 5, 10:10 UTC | Jul 5, 21:34 UTC | 11h 24m |
| 2026-07-04 | UAL102 | - | Jul 4, 22:15 UTC | Jul 5, 07:00 UTC | 8h 45m |
| 2026-07-04 | UAL102 | IAH → MUC | Jul 4, 22:22 UTC | Jul 5, 07:41 UTC | 9h 19m |
| 2026-07-04 | UAL879 | - | Jul 4, 09:30 UTC | Jul 4, 19:00 UTC | 9h 30m |
| 2026-07-04 | UAL879 | LHR → IAH | Jul 4, 09:25 UTC | Jul 4, 19:11 UTC | 9h 46m |
| 2026-07-03 | UAL880 | IAH → LHR | Jul 3, 22:35 UTC | Jul 4, 07:15 UTC | 8h 40m |
| 2026-07-03 | UAL880 | IAH → LHR | Jul 3, 22:26 UTC | Jul 4, 07:11 UTC | 8h 45m |
| 2026-07-03 | UAL879 | - | Jul 3, 09:25 UTC | Jul 3, 18:55 UTC | 9h 30m |
| 2026-07-02 | UAL918 | IAD → LHR | Jul 2, 23:36 UTC | Jul 3, 05:46 UTC | 6h 10m |
| 2026-07-02 | UAL918 | IAD → LHR | Jul 2, 23:25 UTC | Jul 3, 05:55 UTC | 6h 30m |
| 2026-07-02 | UAL914 | CDG → IAD | Jul 2, 10:40 UTC | Jul 2, 18:30 UTC | 7h 50m |
| 2026-07-01 | UAL990 | - | Jul 1, 22:30 UTC | Jul 2, 08:15 UTC | 9h 45m |
| 2026-07-01 | UAL1593 | - | Jul 1, 13:50 UTC | Jul 1, 18:55 UTC | 5h 5m |
| 2026-07-01 | UAL1141 | SFO → EWR | Jul 1, 06:15 UTC | Jul 1, 11:00 UTC | 4h 45m |
| 2026-06-29 | UAL673 | BCN → SFO | Jun 29, 14:31 UTC | Jun 30, 01:40 UTC | 11h 9m |
| 2026-06-29 | UAL673 | BCN → SFO | Jun 29, 14:31 UTC | Jun 30, 01:36 UTC | 11h 5m |
| 2026-06-29 | UAL673 | - | Jun 29, 14:25 UTC | Jun 29, 16:44 UTC | 2h 20m |
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 N794UA page for operator, model, and routing details .