Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A239E0

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N24202 · BOEING 737-800 · operated by UNITED AIRLINES INC

Hex
A239E0
Octal
50434740
Decimal
10,631,648
Country
US
Tail
N24202
Type
B738
No current signal · last broadcast Jul 26, 20:45 UTC
Flights observed
351
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 20:45 UTC

Last known position

Most recent position reported by Mode-S A239E0.

Country allocation

The ICAO 24-bit address A239E0 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
UAL2637 - 6 2026-07-19
UAL766 United Airlines 4 2026-04-16
UAL2745 United Airlines 4 2026-07-19
UAL2424 United Airlines 4 2026-04-26
UAL1325 United Airlines 4 2026-04-18
UAL1185 United Airlines 4 2026-06-05
UAL637 United Airlines 3 2026-04-13
UAL547 United Airlines 3 2026-06-05
UAL525 - 3 2026-07-11
UAL424 United Airlines 3 2026-06-09
UAL3890 United Airlines 3 2026-07-20
UAL378 United Airlines 3 2026-07-18
UAL364 United Airlines 3 2026-05-16
UAL2635 United Airlines 3 2026-07-26
UAL2422 United Airlines 3 2026-04-17
UAL235 United Airlines 3 2026-04-26
UAL2272 United Airlines 3 2026-05-14
UAL1935 United Airlines 3 2026-06-12
UAL1592 United Airlines 3 2026-05-01
UAL1501 United Airlines 3 2026-06-03

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL2000 LGA → IAH Jul 26, 20:05 UTCJul 26, 20:45 UTC40m
2026-07-26 UAL2635 IAH → LGA Jul 26, 15:42 UTCJul 26, 17:00 UTC1h 18m
2026-07-26 UAL2635 IAH → LGA Jul 26, 15:30 UTCJul 26, 17:15 UTC1h 45m
2026-07-26 UAL1657 IAH → PHL Jul 26, 12:15 UTCJul 26, 13:55 UTC1h 40m
2026-07-25 UAL592 BOS → EWR Jul 25, 16:05 UTCJul 25, 17:50 UTC1h 45m
2026-07-25 UAL2795 SFO → ORD Jul 25, 12:35 UTCJul 25, 14:10 UTC1h 35m
2026-07-25 UAL3889 MCO → EWR Jul 25, 04:25 UTCJul 25, 04:45 UTC20m
2026-07-25 UAL3889 MCO → EWR Jul 25, 04:05 UTCJul 25, 04:30 UTC25m
2026-07-20 UAL3890 NAS → EWR Jul 20, 03:55 UTCJul 20, 04:55 UTC1h 0m
2026-07-20 UAL1790 EWR → MYR Jul 20, 00:25 UTCJul 20, 02:50 UTC2h 25m
2026-07-19 UAL2745 HNL → SFO Jul 19, 20:00 UTCJul 19, 22:15 UTC2h 15m
2026-07-19 UAL2637 DEN → GRR Jul 19, 16:10 UTCJul 19, 18:25 UTC2h 15m
2026-07-19 UAL8207 - Jul 19, 00:50 UTCJul 19, 03:20 UTC2h 30m
2026-07-18 UAL3904 - Jul 18, 20:45 UTCJul 18, 21:35 UTC50m
2026-07-18 UAL378 ORD → EWR Jul 18, 16:30 UTCJul 18, 18:45 UTC2h 15m
2026-07-18 UAL762 - Jul 18, 13:05 UTCJul 18, 14:40 UTC1h 35m
2026-07-18 UAL2768 LGA → ORD Jul 18, 03:00 UTCJul 18, 04:50 UTC1h 50m
2026-07-18 UAL2809 ORD → LGA Jul 18, 00:00 UTCJul 18, 01:45 UTC1h 45m
2026-07-17 UAL493 - Jul 17, 20:50 UTCJul 17, 22:10 UTC1h 20m
2026-07-17 UAL2849 EWR → DOM Jul 17, 16:19 UTCJul 17, 17:09 UTC50m
2026-07-17 UAL2151 PDX → DEN Jul 17, 13:15 UTCJul 17, 13:45 UTC30m
2026-07-17 UAL2151 PDX → DEN Jul 17, 13:27 UTCJul 17, 13:45 UTC18m
2026-07-17 UAL630 ORD → MSN Jul 17, 03:50 UTCJul 17, 04:20 UTC30m
2026-07-17 UAL630 ORD → MSN Jul 17, 03:30 UTCJul 17, 04:17 UTC47m
2026-07-16 UAL1316 - Jul 16, 23:40 UTCJul 17, 01:59 UTC2h 20m
2026-07-16 UAL2844 ORD → SAT Jul 16, 20:19 UTCJul 16, 22:40 UTC2h 20m
2026-07-16 UAL1310 LGA → ORD Jul 16, 16:19 UTCJul 16, 18:34 UTC2h 15m
2026-07-16 UAL2617 ORD → LGA Jul 16, 13:25 UTCJul 16, 15:00 UTC1h 35m
2026-07-16 UAL1856 - Jul 16, 11:10 UTCJul 16, 12:00 UTC50m
2026-07-16 UAL1839 ORD → DSM Jul 16, 04:05 UTCJul 16, 04:50 UTC45m
2026-07-16 UAL2446 LGA → ORD Jul 16, 00:45 UTCJul 16, 02:40 UTC1h 55m
2026-07-15 UAL1617 - Jul 15, 21:30 UTCJul 15, 23:20 UTC1h 50m
2026-07-15 UAL714 - Jul 15, 17:45 UTCJul 15, 19:45 UTC2h 0m
2026-07-15 UAL709 - Jul 15, 15:05 UTCJul 15, 16:40 UTC1h 35m
2026-07-15 UAL1297 - Jul 15, 12:15 UTCJul 15, 13:50 UTC1h 35m
2026-07-15 UAL1989 ORD → RDU Jul 15, 00:35 UTCJul 15, 02:05 UTC1h 30m
2026-07-14 UAL1398 COS → ORD Jul 14, 18:20 UTCJul 14, 20:25 UTC2h 5m
2026-07-14 UAL1082 - Jul 14, 15:25 UTCJul 14, 17:15 UTC1h 50m
2026-07-14 UAL2822 LGA → ORD Jul 14, 11:37 UTCJul 14, 13:21 UTC1h 44m
2026-07-14 UAL2822 LGA → ORD Jul 14, 11:45 UTCJul 14, 13:20 UTC1h 35m
2026-07-14 UAL1655 ORD → LGA Jul 14, 01:10 UTCJul 14, 02:55 UTC1h 45m
2026-07-13 UAL329 - Jul 13, 21:05 UTCJul 13, 23:00 UTC1h 55m
2026-07-13 UAL2418 - Jul 13, 16:20 UTCJul 13, 19:40 UTC3h 20m
2026-07-13 UAL596 LAS → DEN Jul 13, 12:44 UTCJul 13, 13:52 UTC1h 8m
2026-07-13 UAL596 LAS → DEN Jul 13, 12:30 UTCJul 13, 13:55 UTC1h 25m
2026-07-13 UAL1546 LAX → LAS Jul 13, 06:10 UTCJul 13, 07:01 UTC50m
2026-07-13 UAL1546 LAX → LAS Jul 13, 06:17 UTCJul 13, 07:01 UTC44m
2026-07-13 UAL2282 - Jul 13, 04:15 UTCJul 13, 04:55 UTC40m
2026-07-13 UAL751 SFO → LAS Jul 13, 01:25 UTCJul 13, 02:30 UTC1h 5m
2026-07-12 UAL1212 SFO → SFO Jul 12, 16:10 UTCJul 12, 23:35 UTC7h 25m

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 N24202 page for operator, model, and routing details .

Mode-S A239E0 frequently asked

What is Mode-S code A239E0?
A239E0 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N24202.
Where is Mode-S A239E0 registered?
Mode-S code A239E0 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 A239E0 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 20:45 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A239E0, octal 50434740, decimal 10,631,648.
What flights does A239E0 operate?
Mode-S A239E0 has broadcast 20 distinct callsigns, including UAL2637, UAL766, UAL2745, UAL2424, UAL1325.