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
- 208
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 6h 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 | - | 9 | 2026-07-05 |
| UAL62 | - | 9 | 2026-07-04 |
| UAL83 | United Airlines | 8 | 2026-06-24 |
| UAL6 | - | 7 | 2026-07-03 |
| UAL199 | United Airlines | 7 | 2026-07-07 |
| UAL63 | - | 6 | 2026-07-05 |
| UAL33 | - | 6 | 2026-07-06 |
| UAL26 | United Airlines | 6 | 2026-05-21 |
| UAL198 | - | 6 | 2026-07-07 |
| UAL870 | - | 5 | 2026-07-14 |
| UAL32 | - | 5 | 2026-07-02 |
| UAL182 | United Airlines | 5 | 2026-05-19 |
| UAL122 | - | 5 | 2026-06-17 |
| UAL821 | - | 4 | 2026-07-12 |
| UAL820 | - | 4 | 2026-07-12 |
| UAL82 | - | 4 | 2026-06-24 |
| UAL29 | - | 4 | 2026-06-20 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-14 | UAL870 | - | Jul 14, 00:50 UTC | Jul 14, 01:20 UTC | 30m |
| 2026-07-14 | UAL870 | SYD → SFO | Jul 14, 00:45 UTC | Jul 14, 13:50 UTC | 13h 5m |
| 2026-07-13 | UAL839 | - | Jul 13, 06:40 UTC | Jul 13, 21:05 UTC | 14h 25m |
| 2026-07-12 | UAL821 | HKG → LAX | Jul 12, 15:01 UTC | Jul 13, 04:10 UTC | 13h 10m |
| 2026-07-12 | UAL821 | HKG → LAX | Jul 12, 14:56 UTC | Jul 13, 04:05 UTC | 13h 9m |
| 2026-07-12 | UAL821 | - | Jul 12, 11:01 UTC | Jul 12, 11:15 UTC | 15m |
| 2026-07-12 | UAL821 | - | Jul 12, 08:55 UTC | Jul 12, 09:05 UTC | 10m |
| 2026-07-12 | UAL820 | - | Jul 12, 02:35 UTC | Jul 12, 02:55 UTC | 20m |
| 2026-07-12 | UAL820 | - | Jul 12, 00:35 UTC | Jul 12, 00:50 UTC | 15m |
| 2026-07-11 | UAL820 | - | Jul 11, 22:01 UTC | Jul 11, 22:25 UTC | 25m |
| 2026-07-11 | UAL820 | - | Jul 11, 07:55 UTC | Jul 11, 21:10 UTC | 13h 15m |
| 2026-07-09 | UAL772 | - | Jul 9, 05:40 UTC | Jul 9, 16:30 UTC | 10h 50m |
| 2026-07-08 | UAL772 | - | Jul 8, 17:35 UTC | Jul 9, 16:30 UTC | 22h 55m |
| 2026-07-08 | UAL771 | - | Jul 8, 17:15 UTC | Jul 9, 15:30 UTC | 22h 15m |
| 2026-07-08 | UAL771 | - | Jul 8, 07:35 UTC | Jul 9, 07:30 UTC | 23h 55m |
| 2026-07-08 | UAL771 | - | Jul 8, 07:15 UTC | Jul 8, 19:25 UTC | 12h 10m |
| 2026-07-07 | UAL199 | PVG → LAX | Jul 7, 13:00 UTC | Jul 7, 14:45 UTC | 1h 45m |
| 2026-07-07 | UAL199 | PVG → LAX | Jul 7, 07:00 UTC | Jul 7, 23:40 UTC | 16h 40m |
| 2026-07-07 | UAL199 | PVG → LAX | Jul 7, 01:35 UTC | Jul 7, 23:40 UTC | 22h 5m |
| 2026-07-07 | UAL198 | - | Jul 7, 00:55 UTC | Jul 7, 23:30 UTC | 22h 35m |
| 2026-07-06 | UAL198 | - | Jul 6, 21:00 UTC | Jul 7, 08:45 UTC | 11h 45m |
| 2026-07-06 | UAL198 | LAX → PVG | Jul 6, 20:56 UTC | Jul 7, 09:36 UTC | 12h 40m |
| 2026-07-06 | UAL33 | - | Jul 6, 08:00 UTC | Jul 6, 17:25 UTC | 9h 25m |
| 2026-07-06 | UAL33 | NRT → LAX | Jul 6, 08:05 UTC | Jul 6, 17:10 UTC | 9h 5m |
| 2026-07-05 | UAL7 | - | Jul 5, 16:10 UTC | Jul 6, 04:55 UTC | 12h 45m |
| 2026-07-05 | UAL63 | - | Jul 5, 01:05 UTC | Jul 5, 10:05 UTC | 9h 0m |
| 2026-07-04 | UAL62 | - | Jul 4, 00:05 UTC | Jul 4, 01:30 UTC | 1h 25m |
| 2026-07-04 | UAL62 | IAH → GRU | Jul 4, 00:03 UTC | Jul 4, 09:13 UTC | 9h 10m |
| 2026-07-03 | UAL6 | - | Jul 3, 08:15 UTC | Jul 3, 20:10 UTC | 11h 55m |
| 2026-07-02 | UAL32 | - | Jul 2, 18:25 UTC | Jul 2, 19:20 UTC | 55m |
| 2026-07-02 | UAL32 | LAX → NRT | Jul 2, 18:15 UTC | Jul 3, 05:12 UTC | 10h 57m |
| 2026-07-01 | UAL199 | PVG → LAX | Jul 1, 07:05 UTC | Jul 1, 23:40 UTC | 16h 35m |
| 2026-06-30 | UAL198 | - | Jun 30, 21:00 UTC | Jul 1, 15:00 UTC | 18h 0m |
| 2026-06-30 | UAL33 | - | Jun 30, 08:10 UTC | Jun 30, 17:15 UTC | 9h 5m |
| 2026-06-29 | UAL7 | - | Jun 29, 16:25 UTC | Jun 30, 04:50 UTC | 12h 26m |
| 2026-06-28 | UAL6 | - | Jun 28, 08:25 UTC | Jun 28, 08:55 UTC | 30m |
| 2026-06-28 | UAL6 | NRT → IAH | Jun 28, 08:26 UTC | Jun 28, 19:32 UTC | 11h 6m |
| 2026-06-27 | UAL32 | - | Jun 27, 18:24 UTC | Jun 28, 05:09 UTC | 10h 45m |
| 2026-06-26 | UAL935 | LHR → LAX | Jun 26, 12:30 UTC | Jun 26, 22:46 UTC | 10h 16m |
| 2026-06-26 | UAL935 | - | Jun 26, 12:34 UTC | Jun 26, 13:30 UTC | 55m |
| 2026-06-25 | UAL923 | LAX → LHR | Jun 25, 22:45 UTC | Jun 26, 09:00 UTC | 10h 15m |
| 2026-06-25 | UAL2692 | - | Jun 25, 15:10 UTC | Jun 25, 20:09 UTC | 5h 0m |
| 2026-06-24 | UAL83 | DEL → EWR | Jun 24, 19:34 UTC | Jun 25, 11:04 UTC | 15h 30m |
| 2026-06-24 | UAL83 | DEL → EWR | Jun 24, 19:24 UTC | Jun 25, 11:00 UTC | 15h 36m |
| 2026-06-24 | UAL82 | EWR → DEL | Jun 24, 03:40 UTC | Jun 24, 17:05 UTC | 13h 25m |
| 2026-06-23 | UAL713 | SFO → EWR | Jun 23, 17:44 UTC | Jun 23, 22:15 UTC | 4h 30m |
| 2026-06-23 | UAL61 | - | Jun 23, 01:10 UTC | Jun 23, 14:10 UTC | 13h 0m |
| 2026-06-22 | UAL60 | SFO → MEL | Jun 22, 07:19 UTC | Jun 22, 22:30 UTC | 15h 10m |
| 2026-06-21 | UAL28 | SIN → SFO | Jun 21, 13:40 UTC | Jun 22, 04:33 UTC | 14h 53m |
| 2026-06-21 | UAL28 | - | Jun 21, 16:39 UTC | Jun 22, 04:54 UTC | 12h 15m |
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 .