Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A2C35B

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N27734 · BOEING 737-700 · operated by UNITED AIRLINES INC

Hex
A2C35B
Octal
50541533
Decimal
10,666,843
Country
US
Tail
N27734
Type
B737
No current signal · last broadcast 8h ago
Flights observed
401
Distinct callsigns
20
Country
US
Last broadcast
8h ago

Last known position

Most recent position reported by Mode-S A2C35B.

Country allocation

The ICAO 24-bit address A2C35B 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
UAL780 - 8 2026-06-28
UAL632 - 7 2026-06-30
UAL2116 - 6 2026-06-27
UAL1860 - 6 2026-07-10
UAL1709 - 6 2026-06-28
UAL2639 - 5 2026-06-28
UAL2346 United Airlines 5 2026-07-09
UAL2247 United Airlines 5 2026-04-22
UAL1926 - 5 2026-07-01
UAL1861 - 5 2026-07-10
UAL1024 United Airlines 5 2026-05-22
UAL658 - 4 2026-06-15
UAL528 - 4 2026-06-23
UAL307 - 4 2026-06-22
UAL2846 - 4 2026-07-10
UAL241 - 4 2026-07-13
UAL2264 - 4 2026-07-02
UAL2256 - 4 2026-07-11
UAL2190 United Airlines 4 2026-04-26
UAL2026 - 4 2026-07-11

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-13 UAL241 - Jul 13, 22:20 UTCJul 14, 02:15 UTC3h 55m
2026-07-11 UAL1507 - Jul 11, 23:20 UTCJul 12, 16:10 UTC16h 50m
2026-07-11 UAL2026 - Jul 11, 18:20 UTCJul 11, 19:30 UTC1h 10m
2026-07-11 UAL2256 - Jul 11, 15:55 UTCJul 11, 17:10 UTC1h 15m
2026-07-11 UAL2399 - Jul 11, 11:30 UTCJul 11, 13:20 UTC1h 50m
2026-07-10 UAL2846 - Jul 10, 22:20 UTCJul 11, 00:00 UTC1h 40m
2026-07-10 UAL1860 - Jul 10, 18:25 UTCJul 10, 20:10 UTC1h 45m
2026-07-10 UAL1860 VER → IAH Jul 10, 18:29 UTCJul 10, 20:09 UTC1h 40m
2026-07-10 UAL1861 - Jul 10, 15:25 UTCJul 10, 17:25 UTC2h 0m
2026-07-10 UAL2399 - Jul 10, 11:30 UTCJul 10, 13:30 UTC2h 0m
2026-07-09 UAL2846 - Jul 9, 22:25 UTCJul 10, 00:15 UTC1h 50m
2026-07-09 UAL1725 - Jul 9, 19:40 UTCJul 9, 20:55 UTC1h 15m
2026-07-09 UAL2346 SFO → DFW Jul 9, 15:55 UTCJul 9, 16:45 UTC50m
2026-07-09 UAL2346 SFO → DFW Jul 9, 16:05 UTCJul 9, 17:47 UTC1h 42m
2026-07-09 UAL2464 RSW → EWR Jul 9, 10:30 UTCJul 9, 13:00 UTC2h 30m
2026-07-09 UAL1259 - Jul 9, 00:10 UTCJul 9, 02:35 UTC2h 25m
2026-07-08 UAL1381 - Jul 8, 19:20 UTCJul 8, 22:35 UTC3h 15m
2026-07-08 UAL2670 - Jul 8, 15:20 UTCJul 8, 18:00 UTC2h 40m
2026-07-08 UAL1201 - Jul 8, 01:25 UTCJul 8, 12:50 UTC11h 25m
2026-07-07 UAL497 - Jul 7, 19:15 UTCJul 7, 22:00 UTC2h 45m
2026-07-07 UAL2281 - Jul 7, 15:15 UTCJul 7, 17:50 UTC2h 35m
2026-07-07 UAL1409 - Jul 7, 09:55 UTCJul 7, 13:40 UTC3h 45m
2026-07-06 UAL2161 - Jul 6, 23:40 UTCJul 7, 02:55 UTC3h 15m
2026-07-06 UAL2026 - Jul 6, 19:55 UTCJul 6, 20:55 UTC1h 0m
2026-07-06 UAL2256 IAH → MTY Jul 6, 17:40 UTCJul 6, 18:40 UTC1h 0m
2026-07-06 UAL2399 - Jul 6, 11:50 UTCJul 6, 13:45 UTC1h 55m
2026-07-05 UAL2846 - Jul 5, 22:20 UTCJul 6, 00:05 UTC1h 45m
2026-07-05 UAL1725 - Jul 5, 15:30 UTCJul 5, 20:30 UTC5h 0m
2026-07-05 UAL2744 MCO → EWR Jul 5, 10:30 UTCJul 5, 11:15 UTC45m
2026-07-04 UAL519 - Jul 4, 21:55 UTCJul 4, 22:40 UTC45m
2026-07-04 UAL519 IAH → MSY Jul 4, 22:06 UTCJul 4, 22:52 UTC46m
2026-07-04 UAL2405 SFO → LAS Jul 4, 15:15 UTCJul 4, 19:30 UTC4h 15m
2026-07-04 UAL1986 - Jul 4, 02:40 UTCJul 4, 05:10 UTC2h 30m
2026-07-03 UAL2388 - Jul 3, 21:45 UTCJul 4, 00:15 UTC2h 30m
2026-07-03 UAL2388 IAH → IAD Jul 3, 21:56 UTCJul 4, 00:14 UTC2h 18m
2026-07-03 UAL2026 - Jul 3, 18:15 UTCJul 3, 19:15 UTC1h 0m
2026-07-03 UAL2256 IAH → MTY Jul 3, 15:20 UTCJul 3, 16:30 UTC1h 10m
2026-07-03 UAL1409 - Jul 3, 09:55 UTCJul 3, 13:20 UTC3h 25m
2026-07-02 UAL2161 - Jul 2, 22:20 UTCJul 3, 01:50 UTC3h 30m
2026-07-02 UAL1725 - Jul 2, 19:20 UTCJul 2, 20:35 UTC1h 15m
2026-07-02 UAL2346 SFO → DFW Jul 2, 15:20 UTCJul 2, 16:30 UTC1h 10m
2026-07-02 UAL2346 SFO → DFW Jul 2, 15:15 UTCJul 2, 17:11 UTC1h 56m
2026-07-02 UAL396 - Jul 2, 11:50 UTCJul 2, 13:25 UTC1h 35m
2026-07-02 UAL2264 - Jul 2, 02:10 UTCJul 2, 03:25 UTC1h 15m
2026-07-01 UAL376 AUS → IAD Jul 1, 22:15 UTCJul 2, 01:10 UTC2h 55m
2026-07-01 UAL2746 LAS → SFO Jul 1, 17:25 UTCJul 1, 20:15 UTC2h 50m
2026-07-01 UAL445 - Jul 1, 14:45 UTCJul 1, 15:40 UTC55m
2026-07-01 UAL1926 IAD → CLE Jul 1, 12:35 UTCJul 1, 13:25 UTC50m
2026-07-01 UAL1926 IAD → CLE Jul 1, 12:38 UTCJul 1, 13:21 UTC43m
2026-07-01 UAL726 - Jul 1, 06:10 UTCJul 1, 10:00 UTC3h 50m

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 N27734 page for operator, model, and routing details .

Mode-S A2C35B frequently asked

What is Mode-S code A2C35B?
A2C35B is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N27734.
Where is Mode-S A2C35B registered?
Mode-S code A2C35B 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 A2C35B broadcasting right now?
No active broadcast right now. Last signal was 8h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A2C35B, octal 50541533, decimal 10,666,843.
What flights does A2C35B operate?
Mode-S A2C35B has broadcast 20 distinct callsigns, including UAL780, UAL632, UAL2116, UAL1860, UAL1709.