sensors Mode-S transponder
A63DFF
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N501DN · AIRBUS A-350-900 · operated by DELTA AIR LINES INC
- Hex
- A63DFF
- Octal
- 51436777
- Decimal
- 10,894,847
- Country
- US
- Tail
- N501DN
- Type
- A359
- Flights observed
- 197
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 9h ago
Current position
Country allocation
The ICAO 24-bit address A63DFF 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 |
|---|---|---|---|
| DAL120 | Delta Air Lines | 12 | 2026-06-04 |
| DAL7 | Delta Air Lines | 11 | 2026-06-26 |
| DAL171 | - | 11 | 2026-07-06 |
| DAL161 | - | 11 | 2026-07-06 |
| DAL295 | - | 10 | 2026-07-12 |
| DAL167 | - | 9 | 2026-07-13 |
| DAL166 | - | 9 | 2026-07-13 |
| DAL147 | - | 9 | 2026-07-11 |
| DAL196 | - | 8 | 2026-07-01 |
| DAL173 | Delta Air Lines | 8 | 2026-04-18 |
| DAL146 | - | 8 | 2026-07-12 |
| DAL172 | Delta Air Lines | 7 | 2026-04-17 |
| DAL294 | - | 6 | 2026-07-10 |
| DAL281 | - | 6 | 2026-07-02 |
| N501DN | - | 5 | 2026-06-17 |
| DAL8 | - | 5 | 2026-06-24 |
| DAL197 | Delta Air Lines | 5 | 2026-06-30 |
| DAL170 | - | 5 | 2026-07-07 |
| DAL160 | Delta Air Lines | 5 | 2026-06-04 |
| DAL69 | - | 4 | 2026-06-28 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-13 | DAL167 | - | Jul 13, 19:55 UTC | Jul 13, 20:40 UTC | 45m |
| 2026-07-13 | DAL166 | - | Jul 13, 08:25 UTC | Jul 13, 17:25 UTC | 9h 0m |
| 2026-07-12 | DAL295 | - | Jul 12, 15:25 UTC | Jul 13, 04:30 UTC | 13h 5m |
| 2026-07-12 | DAL146 | - | Jul 12, 05:10 UTC | Jul 12, 05:45 UTC | 35m |
| 2026-07-12 | DAL146 | SCL → ATL | Jul 12, 02:38 UTC | Jul 12, 11:18 UTC | 8h 40m |
| 2026-07-11 | DAL147 | - | Jul 11, 03:30 UTC | Jul 11, 09:30 UTC | 6h 0m |
| 2026-07-10 | DAL294 | HND → ATL | Jul 10, 06:50 UTC | Jul 10, 19:25 UTC | 12h 35m |
| 2026-07-09 | DAL121 | MSP → HND | Jul 9, 15:50 UTC | Jul 10, 03:05 UTC | 11h 15m |
| 2026-07-07 | DAL170 | ICN → MSP | Jul 7, 10:55 UTC | Jul 7, 22:40 UTC | 11h 45m |
| 2026-07-06 | DAL171 | - | Jul 6, 18:55 UTC | Jul 7, 07:40 UTC | 12h 45m |
| 2026-07-06 | DAL171 | MSP → ICN | Jul 6, 18:54 UTC | Jul 7, 07:40 UTC | 12h 46m |
| 2026-07-06 | DAL161 | AMS → MSP | Jul 6, 08:10 UTC | Jul 6, 16:10 UTC | 8h 0m |
| 2026-07-05 | DAL70 | - | Jul 5, 19:50 UTC | Jul 6, 03:15 UTC | 7h 25m |
| 2026-07-04 | DAL83 | - | Jul 4, 07:50 UTC | Jul 4, 16:40 UTC | 8h 50m |
| 2026-07-03 | DAL96 | YIP → CDG | Jul 3, 21:40 UTC | Jul 4, 04:25 UTC | 6h 45m |
| 2026-07-03 | DAL388 | SFO → JFK | Jul 3, 02:26 UTC | Jul 3, 15:34 UTC | 13h 8m |
| 2026-07-02 | DAL281 | - | Jul 2, 08:40 UTC | Jul 3, 04:50 UTC | 20h 10m |
| 2026-07-02 | DAL281 | - | Jul 2, 03:50 UTC | Jul 3, 03:45 UTC | 23h 55m |
| 2026-07-01 | DAL281 | SEA → PVG | Jul 1, 23:47 UTC | Jul 2, 11:37 UTC | 11h 50m |
| 2026-07-01 | DAL281 | - | Jul 1, 23:50 UTC | Jul 2, 04:15 UTC | 4h 25m |
| 2026-07-01 | DAL196 | ICN → SEA | Jul 1, 10:30 UTC | Jul 1, 19:40 UTC | 9h 10m |
| 2026-07-01 | DAL196 | ICN → SEA | Jul 1, 10:28 UTC | Jul 1, 19:34 UTC | 9h 6m |
| 2026-06-30 | DAL197 | SEA → ICN | Jun 30, 21:06 UTC | Jul 1, 08:21 UTC | 11h 15m |
| 2026-06-30 | DAL197 | SEA → ICN | Jun 30, 21:10 UTC | Jul 1, 08:15 UTC | 11h 5m |
| 2026-06-30 | DAL68 | - | Jun 30, 05:10 UTC | Jun 30, 14:00 UTC | 8h 50m |
| 2026-06-30 | DAL68 | - | Jun 30, 03:40 UTC | Jun 30, 04:00 UTC | 20m |
| 2026-06-28 | DAL69 | - | Jun 28, 23:50 UTC | Jun 29, 04:04 UTC | 4h 15m |
| 2026-06-28 | DAL69 | SEA → TPE | Jun 28, 23:48 UTC | Jun 29, 11:53 UTC | 12h 5m |
| 2026-06-28 | DAL196 | ICN → SEA | Jun 28, 10:15 UTC | Jun 28, 19:34 UTC | 9h 20m |
| 2026-06-28 | DAL196 | ICN → SEA | Jun 28, 10:12 UTC | Jun 28, 19:28 UTC | 9h 16m |
| 2026-06-27 | DAL197 | SEA → ICN | Jun 27, 20:14 UTC | Jun 28, 07:05 UTC | 10h 50m |
| 2026-06-27 | DAL166 | - | Jun 27, 07:34 UTC | Jun 27, 15:45 UTC | 8h 10m |
| 2026-06-26 | DAL7 | LAX → HND | Jun 26, 17:40 UTC | Jun 26, 18:39 UTC | 1h 0m |
| 2026-06-26 | DAL7 | LAX → HND | Jun 26, 17:35 UTC | Jun 27, 04:48 UTC | 11h 13m |
| 2026-06-25 | DAL291 | - | Jun 25, 14:39 UTC | Jun 26, 01:24 UTC | 10h 45m |
| 2026-06-25 | DAL290 | - | Jun 25, 01:14 UTC | Jun 25, 11:15 UTC | 10h 0m |
| 2026-06-24 | DAL8 | HND → LAX | Jun 24, 08:01 UTC | Jun 24, 16:57 UTC | 8h 56m |
| 2026-06-24 | DAL8 | HND → LAX | Jun 24, 08:04 UTC | Jun 24, 17:05 UTC | 9h 0m |
| 2026-06-23 | DAL167 | - | Jun 23, 19:10 UTC | Jun 24, 03:44 UTC | 8h 35m |
| 2026-06-23 | DAL167 | SEA → HND | Jun 23, 19:05 UTC | Jun 24, 04:21 UTC | 9h 16m |
| 2026-06-21 | DAL166 | HND → SEA | Jun 21, 09:00 UTC | Jun 21, 17:35 UTC | 8h 35m |
| 2026-06-20 | DAL295 | ATL → HND | Jun 20, 15:39 UTC | Jun 21, 04:39 UTC | 13h 0m |
| 2026-06-20 | DAL146 | - | Jun 20, 06:35 UTC | Jun 20, 09:29 UTC | 2h 55m |
| 2026-06-19 | DAL147 | ATL → SCL | Jun 19, 04:22 UTC | Jun 19, 13:20 UTC | 8h 58m |
| 2026-06-19 | DAL147 | - | Jun 19, 04:25 UTC | Jun 19, 05:45 UTC | 1h 20m |
| 2026-06-18 | DAL294 | HND → ATL | Jun 18, 06:35 UTC | Jun 18, 18:55 UTC | 12h 20m |
| 2026-06-17 | N501DN | MSP → HND | Jun 17, 16:05 UTC | Jun 18, 03:35 UTC | 11h 30m |
| 2026-06-16 | DAL170 | ICN → MSP | Jun 16, 11:15 UTC | Jun 16, 22:50 UTC | 11h 36m |
| 2026-06-15 | DAL197 | SEA → ICN | Jun 15, 20:20 UTC | Jun 16, 00:29 UTC | 4h 10m |
| 2026-06-15 | DAL197 | SEA → ICN | Jun 15, 20:18 UTC | Jun 16, 07:30 UTC | 11h 12m |
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 N501DN page for operator, model, and routing details .