Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A3C3E0

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N34131 · BOEING 757-200 · operated by UNITED AIRLINES INC

Hex
A3C3E0
Octal
50741740
Decimal
10,732,512
Country
US
Tail
N34131
Type
B752
No current signal · last broadcast 28m ago
Flights observed
262
Distinct callsigns
20
Country
US
Last broadcast
28m ago

Last known position

Most recent position reported by Mode-S A3C3E0.

Country allocation

The ICAO 24-bit address A3C3E0 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
UAL1758 - 12 2026-06-15
UAL1759 - 11 2026-06-16
UAL2308 United Airlines 9 2026-06-05
UAL37 - 8 2026-06-18
UAL36 - 8 2026-06-18
UAL1283 United Airlines 8 2026-07-02
UAL887 - 7 2026-06-29
UAL2434 - 7 2026-06-17
UAL886 United Airlines 6 2026-06-28
UAL648 United Airlines 6 2026-06-11
UAL2679 United Airlines 6 2026-06-30
UAL2307 United Airlines 6 2026-06-04
UAL2626 - 5 2026-07-07
UAL2336 United Airlines 5 2026-04-25
UAL2127 - 5 2026-06-17
UAL743 United Airlines 4 2026-04-26
UAL398 - 4 2026-07-13
UAL254 United Airlines 4 2026-05-17
UAL238 United Airlines 4 2026-05-27
UAL229 - 4 2026-07-11

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-13 UAL310 - Jul 13, 23:40 UTCJul 14, 06:00 UTC6h 20m
2026-07-13 UAL399 KEF → IAD Jul 13, 11:45 UTCJul 13, 17:50 UTC6h 5m
2026-07-13 UAL398 - Jul 13, 02:40 UTCJul 13, 05:15 UTC2h 35m
2026-07-13 UAL398 IAD → KEF Jul 13, 02:50 UTCJul 13, 08:43 UTC5h 53m
2026-07-12 UAL311 DUB → IAD Jul 12, 08:01 UTCJul 12, 15:10 UTC7h 10m
2026-07-12 UAL311 DUB → IAD Jul 12, 07:57 UTCJul 12, 15:11 UTC7h 14m
2026-07-11 UAL310 IAD → DUB Jul 11, 23:39 UTCJul 12, 05:58 UTC6h 19m
2026-07-11 UAL310 - Jul 11, 23:35 UTCJul 12, 06:01 UTC6h 25m
2026-07-11 UAL229 DUB → IAD Jul 11, 11:35 UTCJul 11, 19:05 UTC7h 30m
2026-07-11 UAL228 IAD → DUB Jul 11, 02:35 UTCJul 11, 09:15 UTC6h 40m
2026-07-10 UAL336K SFO → IAD Jul 10, 18:54 UTCJul 10, 23:47 UTC4h 53m
2026-07-10 UAL336K - Jul 10, 18:35 UTCJul 10, 23:50 UTC5h 15m
2026-07-10 UAL3931 - Jul 10, 16:35 UTCJul 10, 17:35 UTC1h 0m
2026-07-09 UAL2641 - Jul 9, 22:25 UTCJul 10, 03:40 UTC5h 15m
2026-07-09 UAL271 - Jul 9, 12:55 UTCJul 9, 19:40 UTC6h 45m
2026-07-09 UAL270 EWR → SNN Jul 9, 05:31 UTCJul 9, 11:03 UTC5h 32m
2026-07-09 UAL270 - Jul 9, 05:05 UTCJul 9, 11:10 UTC6h 5m
2026-07-08 UAL634 - Jul 8, 19:35 UTCJul 8, 20:30 UTC55m
2026-07-08 UAL634 BIO → EWR Jul 8, 19:13 UTCJul 9, 03:19 UTC8h 6m
2026-07-08 UAL633 - Jul 8, 11:00 UTCJul 8, 17:35 UTC6h 35m
2026-07-08 UAL633 EWR → BIO Jul 8, 10:55 UTCJul 8, 17:38 UTC6h 43m
2026-07-07 UAL2626 SFO → EWR Jul 7, 23:46 UTCJul 8, 04:51 UTC5h 5m
2026-07-07 UAL2626 - Jul 7, 23:25 UTCJul 8, 05:00 UTC5h 35m
2026-07-07 UAL1343 EWR → SFO Jul 7, 16:12 UTCJul 7, 21:15 UTC5h 3m
2026-07-07 UAL1343 EWR → SFO Jul 7, 15:55 UTCJul 7, 21:30 UTC5h 35m
2026-07-07 UAL698 SFO → EWR Jul 7, 05:00 UTCJul 7, 10:35 UTC5h 35m
2026-07-06 UAL1340 EWR → SFO Jul 6, 22:05 UTCJul 7, 03:50 UTC5h 45m
2026-07-06 UAL2227 - Jul 6, 18:40 UTCJul 6, 19:45 UTC1h 5m
2026-07-05 UAL2227 - Jul 5, 21:05 UTCJul 6, 03:15 UTC6h 10m
2026-07-03 UAL712 - Jul 3, 00:40 UTCJul 3, 05:50 UTC5h 10m
2026-07-02 UAL1283 EWR → ATL Jul 2, 18:50 UTCJul 2, 22:40 UTC3h 50m
2026-07-01 UAL663 - Jul 1, 19:55 UTCJul 1, 23:50 UTC3h 55m
2026-07-01 UAL1403 - Jul 1, 13:10 UTCJul 1, 18:15 UTC5h 5m
2026-06-30 UAL2679 DEN → ORD Jun 30, 14:35 UTCJun 30, 20:25 UTC5h 50m
2026-06-30 UAL2626 - Jun 30, 00:14 UTCJun 30, 05:25 UTC5h 11m
2026-06-29 UAL1343 - Jun 29, 17:49 UTCJun 29, 23:14 UTC5h 25m
2026-06-29 UAL887 - Jun 29, 10:10 UTCJun 29, 14:29 UTC4h 20m
2026-06-28 UAL886 EWR → LIM Jun 28, 21:18 UTCJun 29, 04:49 UTC7h 31m
2026-06-28 UAL886 EWR → LIM Jun 28, 20:59 UTCJun 29, 01:05 UTC4h 5m
2026-06-28 UAL2743 - Jun 28, 14:19 UTCJun 28, 19:09 UTC4h 50m
2026-06-27 UAL2191 - Jun 27, 19:29 UTCJun 28, 00:45 UTC5h 15m
2026-06-27 UAL139 - Jun 27, 11:09 UTCJun 27, 11:30 UTC20m
2026-06-27 UAL139 KEF → EWR Jun 27, 11:19 UTCJun 27, 16:38 UTC5h 19m
2026-06-27 UAL398 IAD → KEF Jun 27, 02:45 UTCJun 27, 08:39 UTC5h 55m
2026-06-26 UAL229 DUB → IAD Jun 26, 11:40 UTCJun 26, 19:09 UTC7h 30m
2026-06-26 UAL229 DUB → IAD Jun 26, 11:41 UTCJun 26, 19:01 UTC7h 20m
2026-06-26 UAL228 IAD → DUB Jun 26, 03:10 UTCJun 26, 09:24 UTC6h 15m
2026-06-25 UAL229 DUB → IAD Jun 25, 11:54 UTCJun 25, 19:24 UTC7h 30m
2026-06-25 UAL228 IAD → DUB Jun 25, 02:25 UTCJun 25, 09:14 UTC6h 50m
2026-06-24 UAL399 KEF → IAD Jun 24, 11:29 UTCJun 24, 17:50 UTC6h 20m

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 N34131 page for operator, model, and routing details .

Mode-S A3C3E0 frequently asked

What is Mode-S code A3C3E0?
A3C3E0 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N34131.
Where is Mode-S A3C3E0 registered?
Mode-S code A3C3E0 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 A3C3E0 broadcasting right now?
No active broadcast right now. Last signal was 28m ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A3C3E0, octal 50741740, decimal 10,732,512.
What flights does A3C3E0 operate?
Mode-S A3C3E0 has broadcast 20 distinct callsigns, including UAL1758, UAL1759, UAL2308, UAL37, UAL36.