sensors Mode-S transponder
A2F2FA
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N28987 · BOEING 787-9 Dreamliner · operated by UNITED AIRLINES INC
- Hex
- A2F2FA
- Octal
- 50571372
- Decimal
- 10,679,034
- Country
- US
- Tail
- N28987
- Type
- B789
- Flights observed
- 85
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 1h ago
Last known position
Country allocation
The ICAO 24-bit address A2F2FA 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 |
|---|---|---|---|
| UAL187 | United Airlines | 5 | 2026-05-23 |
| UAL152 | United Airlines | 5 | 2026-05-30 |
| UAL820 | United Airlines | 4 | 2026-05-19 |
| UAL805 | United Airlines | 4 | 2026-04-21 |
| UAL2023 | United Airlines | 4 | 2026-04-20 |
| UAL199 | United Airlines | 4 | 2026-06-01 |
| UAL198 | United Airlines | 4 | 2026-05-31 |
| UAL153 | United Airlines | 4 | 2026-05-31 |
| UAL1011 | United Airlines | 4 | 2026-04-18 |
| UAL821 | United Airlines | 3 | 2026-05-19 |
| UAL79 | United Airlines | 3 | 2026-05-12 |
| UAL3861 | United Airlines | 3 | 2026-04-27 |
| UAL98 | United Airlines | 2 | 2026-05-28 |
| UAL870 | United Airlines | 2 | 2026-05-10 |
| UAL806 | United Airlines | 2 | 2026-04-22 |
| UAL713 | United Airlines | 2 | 2026-05-10 |
| UAL3937 | United Airlines | 2 | 2026-05-07 |
| UAL32 | United Airlines | 2 | 2026-06-02 |
| UAL188 | United Airlines | 2 | 2026-05-22 |
| UAL1855 | United Airlines | 2 | 2026-05-20 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-06-02 | UAL32 | LAX → NRT | Jun 2, 22:15 UTC | Jun 3, 03:25 UTC | 5h 10m |
| 2026-06-02 | UAL32 | LAX → NRT | Jun 2, 22:15 UTC | Jun 3, 08:33 UTC | 10h 18m |
| 2026-06-01 | UAL199 | PVG → LAX | Jun 1, 12:31 UTC | Jun 1, 23:42 UTC | 11h 11m |
| 2026-06-01 | UAL199 | PVG → LAX | Jun 1, 06:10 UTC | Jun 1, 23:50 UTC | 17h 40m |
| 2026-05-31 | UAL198 | LAX → PVG | May 31, 20:31 UTC | Jun 1, 09:02 UTC | 12h 31m |
| 2026-05-31 | UAL198 | LAX → PVG | May 31, 20:30 UTC | Jun 1, 14:25 UTC | 17h 55m |
| 2026-05-31 | UAL153 | HKG → LAX | May 31, 08:25 UTC | May 31, 16:55 UTC | 8h 30m |
| 2026-05-31 | UAL153 | HKG → LAX | May 31, 05:08 UTC | May 31, 16:46 UTC | 11h 38m |
| 2026-05-30 | UAL152 | LAX → HKG | May 30, 12:45 UTC | May 30, 13:00 UTC | 15m |
| 2026-05-29 | UAL152 | LAX → HKG | May 29, 20:15 UTC | May 30, 10:30 UTC | 14h 15m |
| 2026-05-28 | UAL99 | MEL → LAX | May 28, 23:55 UTC | May 29, 13:45 UTC | 13h 50m |
| 2026-05-28 | UAL98 | LAX → MEL | May 28, 06:20 UTC | May 28, 21:35 UTC | 15h 15m |
| 2026-05-28 | UAL98 | LAX → MEL | May 28, 05:59 UTC | May 28, 21:31 UTC | 15h 32m |
| 2026-05-27 | UAL199 | PVG → LAX | May 27, 07:15 UTC | May 27, 23:55 UTC | 16h 40m |
| 2026-05-27 | UAL199 | PVG → LAX | May 27, 02:34 UTC | May 27, 23:55 UTC | 21h 21m |
| 2026-05-27 | UAL198 | LAX → PVG | May 27, 00:55 UTC | May 27, 23:55 UTC | 23h 1m |
| 2026-05-26 | UAL198 | LAX → PVG | May 26, 20:40 UTC | May 27, 14:50 UTC | 18h 10m |
| 2026-05-26 | UAL153 | HKG → LAX | May 26, 05:15 UTC | May 26, 18:05 UTC | 12h 50m |
| 2026-05-26 | UAL153 | HKG → LAX | May 26, 01:55 UTC | May 26, 02:19 UTC | 25m |
| 2026-05-25 | UAL152 | LAX → HKG | May 25, 13:05 UTC | May 25, 13:20 UTC | 15m |
| 2026-05-25 | UAL152 | LAX → HKG | May 25, 12:59 UTC | May 25, 15:06 UTC | 2h 7m |
| 2026-05-24 | UAL152 | LAX → HKG | May 24, 20:20 UTC | May 25, 10:40 UTC | 14h 20m |
| 2026-05-23 | UAL2403 | RDU → EWR | May 23, 16:15 UTC | May 23, 21:10 UTC | 4h 56m |
| 2026-05-23 | UAL187 | JNB → EWR | May 23, 03:20 UTC | May 23, 11:20 UTC | 8h 0m |
| 2026-05-22 | UAL187 | JNB → EWR | May 22, 20:05 UTC | May 22, 20:30 UTC | 25m |
| 2026-05-22 | UAL187 | JNB → EWR | May 22, 20:19 UTC | May 23, 11:14 UTC | 14h 55m |
| 2026-05-22 | UAL188 | EWR → JNB | May 22, 02:30 UTC | May 22, 16:15 UTC | 13h 45m |
| 2026-05-21 | UAL3026 | - | May 21, 13:40 UTC | May 21, 15:10 UTC | 1h 30m |
| 2026-05-20 | UAL1855 | ORD → BOS | May 20, 23:20 UTC | May 21, 03:15 UTC | 3h 55m |
| 2026-05-19 | UAL821 | SFO → MEX | May 19, 14:00 UTC | May 20, 02:25 UTC | 12h 25m |
| 2026-05-19 | UAL821 | SFO → MEX | May 19, 11:15 UTC | May 19, 11:20 UTC | 5m |
| 2026-05-19 | UAL821 | SFO → MEX | May 19, 09:10 UTC | May 19, 09:35 UTC | 25m |
| 2026-05-19 | UAL820 | MEX → SFO | May 19, 02:35 UTC | May 19, 03:05 UTC | 30m |
| 2026-05-19 | UAL820 | MEX → SFO | May 19, 00:35 UTC | May 19, 02:59 UTC | 2h 24m |
| 2026-05-19 | UAL820 | MEX → SFO | May 19, 00:40 UTC | May 19, 01:00 UTC | 20m |
| 2026-05-18 | UAL820 | MEX → SFO | May 18, 07:15 UTC | May 18, 22:05 UTC | 14h 49m |
| 2026-05-17 | UAL33 | NRT → LAX | May 17, 13:10 UTC | May 17, 22:05 UTC | 8h 55m |
| 2026-05-16 | UAL143 | DEN → NRT | May 16, 23:46 UTC | May 17, 10:44 UTC | 10h 58m |
| 2026-05-16 | UAL143 | DEN → NRT | May 16, 23:45 UTC | May 17, 04:50 UTC | 5h 5m |
| 2026-05-16 | UAL142 | NRT → DEN | May 16, 08:01 UTC | May 16, 17:45 UTC | 9h 45m |
| 2026-05-15 | UAL7 | IAH → NRT | May 15, 15:40 UTC | May 16, 04:30 UTC | 12h 50m |
| 2026-05-15 | UAL63 | GRU → IAH | May 15, 01:25 UTC | May 15, 10:45 UTC | 9h 20m |
| 2026-05-14 | UAL62 | IAH → GRU | May 14, 00:20 UTC | May 14, 09:05 UTC | 8h 45m |
| 2026-05-13 | UAL6 | NRT → IAH | May 13, 08:30 UTC | May 13, 19:50 UTC | 11h 20m |
| 2026-05-12 | UAL79 | EWR → NRT | May 12, 15:47 UTC | May 13, 05:03 UTC | 13h 16m |
| 2026-05-12 | UAL79 | EWR → NRT | May 12, 15:50 UTC | May 13, 04:30 UTC | 12h 40m |
| 2026-05-11 | UAL187 | JNB → EWR | May 11, 20:05 UTC | May 12, 11:35 UTC | 15h 30m |
| 2026-05-11 | UAL187 | JNB → EWR | May 11, 20:19 UTC | May 12, 11:37 UTC | 15h 18m |
| 2026-05-11 | UAL188 | EWR → JNB | May 11, 02:45 UTC | May 11, 16:25 UTC | 13h 40m |
| 2026-05-10 | UAL713 | ORD → DEL | May 10, 17:49 UTC | May 10, 22:55 UTC | 5h 5m |
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 N28987 page for operator, model, and routing details .