Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A9D5A2

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N73259 · BOEING 737-800 · operated by UNITED AIRLINES INC

Hex
A9D5A2
Octal
52352642
Decimal
11,130,274
Country
US
Tail
N73259
Type
B738
No current signal · last broadcast Jul 26, 21:05 UTC
Flights observed
468
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:05 UTC

Last known position

Most recent position reported by Mode-S A9D5A2.

Country allocation

The ICAO 24-bit address A9D5A2 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
UAL1612 United Airlines 6 2026-04-17
UAL742 United Airlines 5 2026-04-17
UAL1877 United Airlines 4 2026-07-24
UAL1620 United Airlines 4 2026-06-15
UAL8188 - 3 2026-07-07
UAL551 United Airlines 3 2026-05-23
UAL403 - 3 2026-06-17
UAL364 - 3 2026-06-23
UAL334 - 3 2026-06-29
UAL324 - 3 2026-07-21
UAL2865 United Airlines 3 2026-07-25
UAL2853 - 3 2026-07-04
UAL2456 - 3 2026-06-12
UAL2443 United Airlines 3 2026-05-12
UAL2430 - 3 2026-06-20
UAL2279 United Airlines 3 2026-05-04
UAL2205 - 3 2026-04-13
UAL2196 United Airlines 3 2026-06-07
UAL2181 United Airlines 3 2026-06-10
UAL2167 - 3 2026-07-06

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL2470 DEN → MCI Jul 26, 18:20 UTCJul 26, 21:00 UTC2h 40m
2026-07-26 UAL362 HNL → EWR Jul 26, 14:00 UTCJul 26, 16:35 UTC2h 35m
2026-07-26 UAL362 HNL → EWR Jul 26, 10:15 UTCJul 26, 12:05 UTC1h 50m
2026-07-26 UAL214 HNL → SFO Jul 26, 03:10 UTCJul 26, 04:45 UTC1h 35m
2026-07-26 UAL214 HNL → SFO Jul 26, 03:10 UTCJul 26, 04:42 UTC1h 32m
2026-07-25 UAL1389 CMH → DEN Jul 25, 20:00 UTCJul 25, 22:35 UTC2h 35m
2026-07-25 UAL1389 CMH → DEN Jul 25, 19:40 UTCJul 25, 22:30 UTC2h 50m
2026-07-25 UAL480 DFW → EWR Jul 25, 15:50 UTCJul 25, 18:10 UTC2h 20m
2026-07-25 UAL2865 DEN → ORD Jul 25, 12:15 UTCJul 25, 14:10 UTC1h 55m
2026-07-25 UAL8279 DUB → YUL Jul 25, 02:50 UTCJul 25, 04:55 UTC2h 5m
2026-07-24 UAL1390 LAS → EWR Jul 24, 21:50 UTCJul 25, 01:10 UTC3h 20m
2026-07-24 UAL2011 EWR → SNA Jul 24, 17:20 UTCJul 24, 20:20 UTC3h 0m
2026-07-24 UAL1877 IAH → EWR Jul 24, 13:25 UTCJul 24, 14:00 UTC35m
2026-07-24 UAL1877 IAH → EWR Jul 24, 13:19 UTCJul 24, 13:54 UTC35m
2026-07-24 UAL431 BDL → IAD Jul 24, 01:40 UTCJul 24, 02:00 UTC20m
2026-07-23 UAL296 ORD → FSD Jul 23, 21:55 UTCJul 23, 23:45 UTC1h 50m
2026-07-23 UAL296 ORD → FSD Jul 23, 20:09 UTCJul 23, 23:38 UTC3h 29m
2026-07-23 UAL2257 SNA → EWR Jul 23, 16:10 UTCJul 23, 17:25 UTC1h 15m
2026-07-23 UAL2257 SNA → EWR Jul 23, 16:18 UTCJul 23, 18:50 UTC2h 32m
2026-07-23 UAL1188 RDM → DEN Jul 23, 12:25 UTCJul 23, 14:20 UTC1h 55m
2026-07-23 UAL1588 DEN → RDM Jul 23, 06:15 UTCJul 23, 08:05 UTC1h 50m
2026-07-23 UAL1943 ORD → CHS Jul 23, 02:45 UTCJul 23, 04:35 UTC1h 50m
2026-07-23 UAL1943 ORD → CHS Jul 23, 02:34 UTCJul 23, 04:40 UTC2h 6m
2026-07-22 UAL2327 ORD → SFO Jul 22, 20:15 UTCJul 22, 21:20 UTC1h 5m
2026-07-22 UAL1824 SFO → YVR Jul 22, 14:05 UTCJul 22, 18:00 UTC3h 55m
2026-07-22 UAL1442 OMA → DEN Jul 22, 11:20 UTCJul 22, 12:35 UTC1h 15m
2026-07-22 UAL1787 SFO → DEN Jul 22, 03:40 UTCJul 22, 04:45 UTC1h 5m
2026-07-21 UAL2786 GEG → DEN Jul 21, 23:25 UTCJul 22, 01:25 UTC2h 0m
2026-07-21 UAL2786 GEG → DEN Jul 21, 23:27 UTCJul 22, 01:20 UTC1h 53m
2026-07-21 UAL324 DEN → GEG Jul 21, 19:50 UTCJul 21, 21:40 UTC1h 50m
2026-07-21 UAL640 - Jul 21, 16:00 UTCJul 21, 18:20 UTC2h 20m
2026-07-21 UAL8125 EWR → MSY Jul 21, 03:10 UTCJul 21, 05:40 UTC2h 30m
2026-07-20 UAL1787 SFO → DEN Jul 20, 23:20 UTCJul 21, 01:30 UTC2h 9m
2026-07-20 UAL2455 EWR → ATL Jul 20, 19:40 UTCJul 20, 21:50 UTC2h 10m
2026-07-20 UAL347 PHL → DEN Jul 20, 16:25 UTCJul 20, 18:10 UTC1h 45m
2026-07-20 UAL719 - Jul 20, 01:50 UTCJul 20, 03:40 UTC1h 50m
2026-07-19 UAL1390 LAS → EWR Jul 19, 20:50 UTCJul 20, 00:05 UTC3h 15m
2026-07-19 UAL2011 EWR → SNA Jul 19, 15:55 UTCJul 19, 19:05 UTC3h 10m
2026-07-19 UAL596 LAS → DEN Jul 19, 12:35 UTCJul 19, 14:05 UTC1h 30m
2026-07-19 UAL679 - Jul 19, 02:10 UTCJul 19, 02:55 UTC45m
2026-07-18 UAL244 PVR → LAX Jul 18, 22:35 UTCJul 19, 00:10 UTC1h 35m
2026-07-18 UAL244 PVR → LAX Jul 18, 21:39 UTCJul 19, 00:02 UTC2h 23m
2026-07-18 UAL319 LAX → PVR Jul 18, 17:40 UTCJul 18, 18:55 UTC1h 15m
2026-07-18 UAL319 LAX → PVR Jul 18, 17:38 UTCJul 18, 20:09 UTC2h 31m
2026-07-18 UAL1692 - Jul 18, 13:25 UTCJul 18, 15:40 UTC2h 15m
2026-07-17 UAL692 - Jul 17, 23:50 UTCJul 18, 03:50 UTC4h 1m
2026-07-17 UAL2405 SFO → LAS Jul 17, 17:15 UTCJul 17, 21:05 UTC3h 50m
2026-07-17 UAL1361 - Jul 17, 12:25 UTCJul 17, 15:35 UTC3h 10m
2026-07-16 UAL1680 - Jul 16, 23:59 UTCJul 17, 03:10 UTC3h 10m
2026-07-16 UAL1680 IAH → BDL Jul 16, 23:51 UTCJul 17, 03:08 UTC3h 17m

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 N73259 page for operator, model, and routing details .

Mode-S A9D5A2 frequently asked

What is Mode-S code A9D5A2?
A9D5A2 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N73259.
Where is Mode-S A9D5A2 registered?
Mode-S code A9D5A2 is allocated to United States (US). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is A9D5A2 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 21:05 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A9D5A2, octal 52352642, decimal 11,130,274.
What flights does A9D5A2 operate?
Mode-S A9D5A2 has broadcast 20 distinct callsigns, including UAL1612, UAL742, UAL1877, UAL1620, UAL8188.