Apparatus

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sensors Mode-S transponder

A2B154

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N27274 · operated by UNITED AIRLINES INC

Hex
A2B154
Octal
50530524
Decimal
10,662,228
Country
US
Tail
N27274
Type
B38M
Broadcasting now · callsign UAL1681 · 35,000 ft
Flights observed
452
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:30 UTC

Current position

A2B154 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A2B154 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
UAL1847 - 8 2026-06-12
UAL776 - 6 2026-07-06
UAL2462 United Airlines 6 2026-05-06
UAL1566 - 6 2026-07-12
UAL1717 United Airlines 5 2026-04-21
UAL1063 United Airlines 5 2026-06-05
UAL608 United Airlines 4 2026-05-06
UAL518 - 4 2026-07-18
UAL488 - 4 2026-06-13
UAL437 - 4 2026-07-16
UAL268 - 4 2026-07-09
UAL2252 United Airlines 4 2026-06-05
UAL2153 - 4 2026-07-22
UAL2057 United Airlines 4 2026-05-08
UAL1494 - 4 2026-06-22
UAL1372 United Airlines 4 2026-07-22
UAL527 United Airlines 3 2026-07-18
UAL448 - 3 2026-06-22
UAL2804 United Airlines 3 2026-06-19
UAL2799 - 3 2026-06-27

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL1632 PDX → SFO Jul 26, 22:05 UTCJul 26, 22:30 UTC25m
2026-07-26 UAL1632 PDX → SFO Jul 26, 20:00 UTCJul 26, 20:25 UTC25m
2026-07-26 UAL700 BOS → EWR Jul 26, 15:05 UTCJul 26, 18:05 UTC3h 0m
2026-07-26 UAL2761 AUS → SFO Jul 26, 01:35 UTCJul 26, 04:25 UTC2h 50m
2026-07-26 UAL2761 AUS → SFO Jul 26, 01:32 UTCJul 26, 04:23 UTC2h 51m
2026-07-25 UAL1433 EWR → YVR Jul 25, 20:20 UTCJul 25, 22:40 UTC2h 20m
2026-07-25 UAL1432 IAH → MGA Jul 25, 15:40 UTCJul 25, 17:50 UTC2h 10m
2026-07-25 UAL1432 IAH → MGA Jul 25, 15:25 UTCJul 25, 18:26 UTC3h 1m
2026-07-25 UAL2074 IAD → DEN Jul 25, 11:00 UTCJul 25, 13:15 UTC2h 15m
2026-07-24 UAL2498 IAH → EWR Jul 24, 23:20 UTCJul 25, 01:40 UTC2h 20m
2026-07-24 UAL1903 GUA → IAH Jul 24, 20:30 UTCJul 24, 21:05 UTC35m
2026-07-24 UAL1903 GUA → IAH Jul 24, 18:45 UTCJul 24, 18:50 UTC5m
2026-07-24 UAL1751 IAH → GUA Jul 24, 17:05 UTCJul 24, 17:20 UTC15m
2026-07-24 UAL1751 IAH → GUA Jul 24, 15:00 UTCJul 24, 15:30 UTC30m
2026-07-24 UAL2393 - Jul 24, 12:20 UTCJul 24, 12:55 UTC35m
2026-07-24 UAL1179 IND → IAH Jul 24, 03:35 UTCJul 24, 04:00 UTC25m
2026-07-23 UAL1645 IAH → AUS Jul 23, 22:55 UTCJul 24, 01:20 UTC2h 25m
2026-07-23 UAL1970 SFO → LAS Jul 23, 19:15 UTCJul 23, 21:30 UTC2h 15m
2026-07-23 UAL2396 BOS → EWR Jul 23, 15:35 UTCJul 23, 17:55 UTC2h 20m
2026-07-23 UAL1041 SAN → EWR Jul 23, 11:20 UTCJul 23, 13:35 UTC2h 15m
2026-07-23 UAL8172 YYZ → DTW Jul 23, 03:20 UTCJul 23, 06:30 UTC3h 10m
2026-07-22 UAL2350 SAN → ORD Jul 22, 22:50 UTCJul 23, 00:45 UTC1h 55m
2026-07-22 UAL2153 SFO → RDM Jul 22, 17:54 UTCJul 22, 18:54 UTC1h 0m
2026-07-22 UAL2153 SFO → RDM Jul 22, 17:45 UTCJul 22, 18:55 UTC1h 10m
2026-07-22 UAL1372 SFO → LAS Jul 22, 15:15 UTCJul 22, 16:10 UTC55m
2026-07-22 UAL1372 SFO → LAS Jul 22, 14:49 UTCJul 22, 16:04 UTC1h 15m
2026-07-22 UAL2220 ORD → MIA Jul 22, 00:25 UTCJul 22, 12:45 UTC12h 20m
2026-07-21 UAL2184 - Jul 21, 21:25 UTCJul 21, 22:05 UTC40m
2026-07-21 UAL1524 IAH → EWR Jul 21, 17:05 UTCJul 21, 19:40 UTC2h 35m
2026-07-21 UAL226 BOS → IAH Jul 21, 11:40 UTCJul 21, 15:10 UTC3h 30m
2026-07-21 UAL2656 SNA → DEN Jul 21, 06:15 UTCJul 21, 09:35 UTC3h 20m
2026-07-20 UAL1153 - Jul 20, 22:25 UTCJul 21, 03:10 UTC4h 45m
2026-07-20 UAL394 DEN → ANC Jul 20, 15:50 UTCJul 20, 21:00 UTC5h 10m
2026-07-20 UAL2614 ANC → DEN Jul 20, 07:20 UTCJul 20, 11:55 UTC4h 35m
2026-07-19 UAL2073 DEN → SFO Jul 19, 22:40 UTCJul 20, 05:55 UTC7h 15m
2026-07-19 UAL593 EWR → BOS Jul 19, 01:05 UTCJul 19, 20:05 UTC19h 0m
2026-07-18 UAL593 EWR → BOS Jul 18, 23:25 UTCJul 19, 20:05 UTC20h 40m
2026-07-18 UAL527 XPL → IAH Jul 18, 19:00 UTCJul 18, 21:15 UTC2h 15m
2026-07-18 UAL518 - Jul 18, 15:05 UTCJul 18, 19:00 UTC3h 55m
2026-07-18 UAL518 IAH → XPL Jul 18, 15:00 UTCJul 18, 17:29 UTC2h 29m
2026-07-18 UAL1450 EWR → PBI Jul 18, 10:15 UTCJul 18, 12:50 UTC2h 35m
2026-07-18 UAL2224 - Jul 18, 02:00 UTCJul 18, 04:40 UTC2h 41m
2026-07-17 UAL1099 - Jul 17, 19:55 UTCJul 17, 23:05 UTC3h 10m
2026-07-17 UAL1096 - Jul 17, 15:20 UTCJul 17, 16:59 UTC1h 40m
2026-07-17 UAL1096 IAH → SJO Jul 17, 14:58 UTCJul 17, 18:29 UTC3h 31m
2026-07-17 UAL438 - Jul 17, 07:05 UTCJul 17, 12:19 UTC5h 15m
2026-07-17 UAL438 GEO → IAH Jul 17, 06:46 UTCJul 17, 12:21 UTC5h 35m
2026-07-16 UAL437 - Jul 16, 23:35 UTCJul 17, 01:39 UTC2h 5m
2026-07-16 UAL437 IAH → GEO Jul 16, 23:36 UTCJul 17, 05:08 UTC5h 32m
2026-07-16 UAL527 - Jul 16, 18:55 UTCJul 16, 21:15 UTC2h 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 N27274 page for operator, model, and routing details .

Mode-S A2B154 frequently asked

What is Mode-S code A2B154?
A2B154 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N27274.
Where is Mode-S A2B154 registered?
Mode-S code A2B154 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 A2B154 broadcasting right now?
Yes. Mode-S A2B154 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A2B154, octal 50530524, decimal 10,662,228.
What flights does A2B154 operate?
Mode-S A2B154 has broadcast 20 distinct callsigns, including UAL1847, UAL776, UAL2462, UAL1566, UAL1717.