Apparatus

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sensors Mode-S transponder

A4495C

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N37541 · BOEING 737 MAX 9 · operated by UNITED AIRLINES INC

Hex
A4495C
Octal
51044534
Decimal
10,766,684
Country
US
Tail
N37541
Type
B39M
No current signal · last broadcast Jul 26, 21:00 UTC
Flights observed
402
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:00 UTC

Last known position

Most recent position reported by Mode-S A4495C.

Country allocation

The ICAO 24-bit address A4495C 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
UAL731 - 6 2026-06-26
UAL1723 - 5 2026-06-27
UAL796 United Airlines 4 2026-04-18
UAL2175 United Airlines 4 2026-04-16
UAL1724 United Airlines 4 2026-06-27
UAL1321 - 4 2026-06-26
UAL1118 United Airlines 4 2026-05-07
UAL700 United Airlines 3 2026-05-21
UAL699 United Airlines 3 2026-07-21
UAL655 United Airlines 3 2026-04-16
UAL589 - 3 2026-07-11
UAL413 - 3 2026-06-22
UAL2661 United Airlines 3 2026-06-19
UAL2495 - 3 2026-06-15
UAL2054 - 3 2026-07-14
UAL2036 United Airlines 3 2026-04-28
UAL2002 - 3 2026-07-07
UAL1760 United Airlines 3 2026-07-24
UAL1618 United Airlines 3 2026-05-05
UAL1490 United Airlines 3 2026-06-02

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL1078 EWR → POP Jul 26, 13:00 UTCJul 26, 21:00 UTC8h 0m
2026-07-24 UAL2693 IAD → SFO Jul 24, 20:40 UTCJul 24, 22:30 UTC1h 50m
2026-07-24 UAL1760 IAH → RDU Jul 24, 16:20 UTCJul 24, 17:55 UTC1h 35m
2026-07-23 UAL1489 EWR → STI Jul 23, 23:30 UTCJul 24, 13:45 UTC14h 15m
2026-07-23 UAL1574 LAS → SFO Jul 23, 18:20 UTCJul 23, 21:15 UTC2h 55m
2026-07-23 UAL1574 LAS → SFO Jul 23, 18:13 UTCJul 23, 21:15 UTC3h 2m
2026-07-23 UAL454 BOS → EWR Jul 23, 13:25 UTCJul 23, 16:25 UTC3h 0m
2026-07-22 UAL404 SFO → DEN Jul 22, 23:55 UTCJul 23, 02:50 UTC2h 55m
2026-07-22 UAL1036 LIR → IAH Jul 22, 17:27 UTCJul 22, 20:02 UTC2h 35m
2026-07-22 UAL2009 IAH → LIR Jul 22, 12:20 UTCJul 22, 20:05 UTC7h 45m
2026-07-22 UAL8210 - Jul 22, 00:15 UTCJul 22, 02:30 UTC2h 15m
2026-07-22 UAL8210 ORD → IAH Jul 22, 00:11 UTCJul 22, 02:26 UTC2h 15m
2026-07-21 UAL699 BWI → SFO Jul 21, 22:05 UTCJul 21, 22:10 UTC5m
2026-07-21 UAL699 BWI → SFO Jul 21, 19:50 UTCJul 21, 22:10 UTC2h 20m
2026-07-21 UAL699 BWI → SFO Jul 21, 19:50 UTCJul 21, 21:50 UTC2h 0m
2026-07-21 UAL462 EWR → PBI Jul 21, 14:25 UTCJul 21, 18:10 UTC3h 45m
2026-07-20 UAL1964 IAD → SEA Jul 20, 22:10 UTCJul 21, 01:55 UTC3h 44m
2026-07-20 UAL2204 - Jul 20, 17:35 UTCJul 20, 20:30 UTC2h 55m
2026-07-20 UAL1144 - Jul 20, 13:50 UTCJul 20, 15:35 UTC1h 45m
2026-07-20 UAL1207 - Jul 20, 10:25 UTCJul 20, 12:25 UTC2h 0m
2026-07-19 UAL2629 LGA → IAH Jul 19, 23:25 UTCJul 20, 01:30 UTC2h 5m
2026-07-19 UAL2629 LGA → IAH Jul 19, 23:05 UTCJul 20, 01:29 UTC2h 24m
2026-07-19 UAL609 ORD → MCO Jul 19, 19:25 UTCJul 19, 21:30 UTC2h 5m
2026-07-19 UAL356 DEN → TPA Jul 19, 14:00 UTCJul 19, 17:05 UTC3h 5m
2026-07-18 UAL1938 RSW → EWR Jul 18, 23:40 UTCJul 19, 04:05 UTC4h 25m
2026-07-18 UAL2435 IAD → SFO Jul 18, 17:25 UTCJul 18, 19:45 UTC2h 20m
2026-07-18 UAL1073 IAD → MIA Jul 18, 13:35 UTCJul 18, 15:45 UTC2h 10m
2026-07-18 UAL498 - Jul 18, 06:40 UTCJul 18, 09:00 UTC2h 20m
2026-07-18 UAL498 PDX → IAD Jul 18, 06:40 UTCJul 18, 11:12 UTC4h 32m
2026-07-17 UAL780 IAD → LAS Jul 17, 22:15 UTCJul 18, 03:10 UTC4h 56m
2026-07-17 UAL1071 - Jul 17, 15:35 UTCJul 17, 20:10 UTC4h 35m
2026-07-17 UAL1513 IAH → SFO Jul 17, 01:59 UTCJul 17, 07:00 UTC5h 0m
2026-07-16 UAL1473 EWR → EWR Jul 16, 14:25 UTCJul 16, 23:15 UTC8h 50m
2026-07-16 UAL1905 - Jul 16, 06:55 UTCJul 16, 11:50 UTC4h 55m
2026-07-16 UAL1904 - Jul 16, 00:25 UTCJul 16, 04:55 UTC4h 30m
2026-07-15 UAL1628 EWR → EWR Jul 15, 13:10 UTCJul 15, 22:20 UTC9h 10m
2026-07-15 UAL427 SAN → EWR Jul 15, 05:50 UTCJul 15, 10:55 UTC5h 5m
2026-07-14 UAL2054 IAD → SAN Jul 14, 22:15 UTCJul 15, 02:40 UTC4h 24m
2026-07-14 UAL1992 EWR → IAD Jul 14, 19:25 UTCJul 14, 20:05 UTC40m
2026-07-14 UAL1197 - Jul 14, 15:15 UTCJul 14, 17:35 UTC2h 20m
2026-07-14 UAL1771 - Jul 14, 11:15 UTCJul 14, 13:30 UTC2h 15m
2026-07-14 UAL2767 DEN → EWR Jul 14, 01:25 UTCJul 14, 04:50 UTC3h 25m
2026-07-13 UAL1092 - Jul 13, 20:35 UTCJul 13, 23:15 UTC2h 40m
2026-07-13 UAL1092 PIT → DEN Jul 13, 20:35 UTCJul 13, 23:10 UTC2h 35m
2026-07-13 UAL1308 DEN → PIT Jul 13, 16:30 UTCJul 13, 19:10 UTC2h 40m
2026-07-13 UAL1362 DEN → DEN Jul 13, 01:40 UTCJul 13, 14:10 UTC12h 30m
2026-07-12 UAL1092 - Jul 12, 20:35 UTCJul 12, 23:15 UTC2h 40m
2026-07-12 UAL1308 - Jul 12, 16:30 UTCJul 12, 19:10 UTC2h 40m
2026-07-12 UAL1607 - Jul 12, 12:25 UTCJul 12, 14:35 UTC2h 10m
2026-07-12 UAL2477 - Jul 12, 06:35 UTCJul 12, 10:20 UTC3h 45m

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 N37541 page for operator, model, and routing details .

Mode-S A4495C frequently asked

What is Mode-S code A4495C?
A4495C is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N37541.
Where is Mode-S A4495C registered?
Mode-S code A4495C 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 A4495C broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 21:00 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A4495C, octal 51044534, decimal 10,766,684.
What flights does A4495C operate?
Mode-S A4495C has broadcast 20 distinct callsigns, including UAL731, UAL1723, UAL796, UAL2175, UAL1724.