sensors Mode-S transponder
A2CB9E
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N27997 · BOEING 787-9 Dreamliner · operated by BOEING CO
- Hex
- A2CB9E
- Octal
- 50545636
- Decimal
- 10,668,958
- Country
- US
- Tail
- N27997
- Type
- B789
- Flights observed
- 118
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 3h ago
Last known position
Country allocation
The ICAO 24-bit address A2CB9E 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 |
|---|---|---|---|
| UAL760 | United Airlines | 10 | 2026-05-23 |
| UAL143 | United Airlines | 10 | 2026-05-24 |
| UAL761 | United Airlines | 9 | 2026-05-23 |
| UAL7 | United Airlines | 7 | 2026-04-27 |
| UAL62 | United Airlines | 7 | 2026-04-26 |
| UAL26 | United Airlines | 6 | 2026-05-21 |
| UAL63 | United Airlines | 5 | 2026-04-27 |
| UAL182 | United Airlines | 5 | 2026-05-19 |
| UAL83 | United Airlines | 4 | 2026-05-06 |
| UAL6 | United Airlines | 4 | 2026-04-25 |
| UAL27 | United Airlines | 4 | 2026-05-20 |
| UAL181 | United Airlines | 4 | 2026-05-20 |
| UAL178 | United Airlines | 4 | 2026-05-22 |
| UAL33 | United Airlines | 3 | 2026-05-25 |
| UAL263 | United Airlines | 3 | 2026-05-12 |
| UAL199 | United Airlines | 3 | 2026-05-26 |
| UAL177 | United Airlines | 3 | 2026-05-22 |
| UAL142 | United Airlines | 3 | 2026-05-19 |
| UAL923 | United Airlines | 2 | 2026-05-07 |
| UAL82 | United Airlines | 2 | 2026-05-06 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-05-29 | UAL863 | SFO → SYD | May 29, 06:40 UTC | May 29, 20:50 UTC | 14h 10m |
| 2026-05-28 | UAL1227 | PHX → IAD | May 28, 21:35 UTC | May 29, 03:05 UTC | 5h 30m |
| 2026-05-28 | UAL123 | ANC → ORD | May 28, 07:10 UTC | May 28, 13:50 UTC | 6h 40m |
| 2026-05-27 | UAL122 | IAD → LHR | May 27, 14:09 UTC | May 27, 20:23 UTC | 6h 14m |
| 2026-05-27 | UAL122 | IAD → LHR | May 27, 14:00 UTC | May 27, 20:25 UTC | 6h 25m |
| 2026-05-27 | UAL2303 | IAD → SAN | May 27, 06:40 UTC | May 27, 11:10 UTC | 4h 31m |
| 2026-05-26 | UAL199 | PVG → LAX | May 26, 06:29 UTC | May 27, 00:04 UTC | 17h 35m |
| 2026-05-25 | UAL198 | LAX → PVG | May 25, 20:30 UTC | May 26, 14:50 UTC | 18h 20m |
| 2026-05-25 | UAL33 | NRT → LAX | May 25, 08:50 UTC | May 25, 18:10 UTC | 9h 20m |
| 2026-05-24 | UAL143 | DEN → NRT | May 24, 18:19 UTC | May 25, 06:31 UTC | 12h 12m |
| 2026-05-24 | UAL143 | DEN → NRT | May 24, 18:20 UTC | May 25, 06:35 UTC | 12h 15m |
| 2026-05-23 | UAL761 | MUC → DEN | May 23, 14:20 UTC | May 24, 00:30 UTC | 10h 11m |
| 2026-05-23 | UAL760 | DEN → MUC | May 23, 02:45 UTC | May 23, 11:30 UTC | 8h 45m |
| 2026-05-23 | UAL760 | DEN → MUC | May 23, 02:45 UTC | May 23, 11:50 UTC | 9h 5m |
| 2026-05-22 | UAL178 | KIX → GUM | May 22, 12:50 UTC | May 22, 23:30 UTC | 10h 40m |
| 2026-05-22 | UAL178 | KIX → GUM | May 22, 12:47 UTC | May 22, 23:25 UTC | 10h 38m |
| 2026-05-22 | UAL177 | GUM → KIX | May 22, 00:40 UTC | May 22, 10:45 UTC | 10h 5m |
| 2026-05-21 | UAL26 | LHR → DEN | May 21, 10:55 UTC | May 21, 19:40 UTC | 8h 45m |
| 2026-05-20 | UAL27 | DEN → LHR | May 20, 23:58 UTC | May 21, 08:07 UTC | 8h 9m |
| 2026-05-20 | UAL27 | DEN → LHR | May 20, 23:55 UTC | May 21, 07:30 UTC | 7h 35m |
| 2026-05-20 | UAL181 | FRA → DEN | May 20, 10:40 UTC | May 20, 20:25 UTC | 9h 45m |
| 2026-05-19 | UAL182 | DEN → FRA | May 19, 21:55 UTC | May 20, 06:40 UTC | 8h 46m |
| 2026-05-19 | UAL142 | NRT → DEN | May 19, 08:40 UTC | May 19, 18:25 UTC | 9h 45m |
| 2026-05-18 | UAL143 | DEN → NRT | May 18, 18:19 UTC | May 19, 06:18 UTC | 11h 59m |
| 2026-05-18 | UAL143 | DEN → NRT | May 18, 18:15 UTC | May 19, 06:20 UTC | 12h 4m |
| 2026-05-17 | UAL26 | LHR → DEN | May 17, 10:55 UTC | May 17, 20:05 UTC | 9h 10m |
| 2026-05-17 | UAL26 | LHR → DEN | May 17, 10:50 UTC | May 17, 20:04 UTC | 9h 14m |
| 2026-05-16 | UAL27 | DEN → LHR | May 16, 23:55 UTC | May 17, 08:20 UTC | 8h 25m |
| 2026-05-16 | UAL181 | FRA → DEN | May 16, 09:40 UTC | May 16, 19:15 UTC | 9h 35m |
| 2026-05-15 | UAL182 | DEN → FRA | May 15, 22:08 UTC | May 16, 06:49 UTC | 8h 41m |
| 2026-05-15 | UAL182 | DEN → FRA | May 15, 22:00 UTC | May 16, 05:30 UTC | 7h 30m |
| 2026-05-15 | UAL142 | NRT → DEN | May 15, 08:35 UTC | May 15, 18:25 UTC | 9h 49m |
| 2026-05-14 | UAL143 | DEN → NRT | May 14, 17:55 UTC | May 15, 04:45 UTC | 10h 50m |
| 2026-05-13 | UAL761 | MUC → DEN | May 13, 14:51 UTC | May 14, 00:40 UTC | 9h 50m |
| 2026-05-13 | UAL760 | DEN → MUC | May 13, 02:45 UTC | May 13, 12:02 UTC | 9h 17m |
| 2026-05-13 | UAL760 | DEN → MUC | May 13, 02:40 UTC | May 13, 12:05 UTC | 9h 25m |
| 2026-05-12 | UAL263 | EWR → PBI | May 12, 14:35 UTC | May 12, 23:35 UTC | 9h 0m |
| 2026-05-12 | UAL262 | DEN → LHR | May 12, 04:20 UTC | May 12, 12:35 UTC | 8h 15m |
| 2026-05-11 | UAL761 | MUC → DEN | May 11, 14:45 UTC | May 11, 16:50 UTC | 2h 5m |
| 2026-05-11 | UAL760 | DEN → MUC | May 11, 02:45 UTC | May 11, 12:00 UTC | 9h 15m |
| 2026-05-10 | UAL761 | MUC → DEN | May 10, 14:30 UTC | May 11, 00:25 UTC | 9h 55m |
| 2026-05-10 | UAL760 | DEN → MUC | May 10, 02:50 UTC | May 10, 11:55 UTC | 9h 5m |
| 2026-05-09 | UAL178 | KIX → GUM | May 9, 12:40 UTC | May 9, 23:25 UTC | 10h 45m |
| 2026-05-08 | UAL177 | GUM → KIX | May 8, 23:45 UTC | May 9, 09:45 UTC | 10h 0m |
| 2026-05-08 | UAL26 | LHR → DEN | May 8, 10:59 UTC | May 8, 19:55 UTC | 8h 55m |
| 2026-05-07 | UAL923 | LAX → LHR | May 7, 22:45 UTC | May 8, 08:44 UTC | 10h 0m |
| 2026-05-07 | UAL923 | LAX → LHR | May 7, 22:48 UTC | May 8, 08:46 UTC | 9h 58m |
| 2026-05-07 | UAL2692 | IAD → PHL | May 7, 14:35 UTC | May 7, 19:35 UTC | 5h 0m |
| 2026-05-06 | UAL83 | DEL → EWR | May 6, 18:40 UTC | May 7, 04:20 UTC | 9h 40m |
| 2026-05-06 | UAL83 | DEL → EWR | May 6, 18:32 UTC | May 7, 10:26 UTC | 15h 54m |
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 N27997 page for operator, model, and routing details .