Apparatus

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sensors Mode-S transponder

A1BEFC

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N211UA · BOEING 777-200 · operated by UNITED AIRLINES INC

Hex
A1BEFC
Octal
50337374
Decimal
10,600,188
Country
US
Tail
N211UA
Type
B772
Broadcasting now · callsign UAL1735 · 39,000 ft
Flights observed
224
Distinct callsigns
20
Country
US
Last broadcast
42m ago

Current position

A1BEFC is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A1BEFC 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
UAL1805 - 25 2026-07-12
UAL1806 - 21 2026-07-12
UAL1736 - 21 2026-07-13
UAL384 United Airlines 17 2026-07-05
UAL383 - 14 2026-06-24
UAL300 United Airlines 12 2026-06-04
UAL1735 - 12 2026-07-14
UAL2358 United Airlines 11 2026-06-04
UAL1169 United Airlines 10 2026-05-13
UAL1170 - 9 2026-07-09
UAL252 - 8 2026-07-06
UAL1758 United Airlines 8 2026-04-26
UAL1731 United Airlines 7 2026-04-26
UAL1157 United Airlines 7 2026-07-07
UAL604 United Airlines 6 2026-06-08
UAL253 - 6 2026-07-06
UAL1158 United Airlines 4 2026-05-13
UAL1141 United Airlines 4 2026-04-22
UAL1604 United Airlines 3 2026-06-05
UAL3867 United Airlines 2 2026-05-22

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 UAL1735 - Jul 14, 10:15 UTCJul 14, 11:00 UTC45m
2026-07-13 UAL1736 - Jul 13, 18:20 UTCJul 13, 20:35 UTC2h 15m
2026-07-13 UAL1736 DEN → OGG Jul 13, 18:23 UTCJul 14, 00:45 UTC6h 22m
2026-07-12 UAL1806 - Jul 12, 08:05 UTCJul 12, 14:15 UTC6h 10m
2026-07-12 UAL1805 - Jul 12, 05:40 UTCJul 12, 05:55 UTC15m
2026-07-11 UAL1805 - Jul 11, 23:30 UTCJul 12, 01:50 UTC2h 20m
2026-07-11 UAL1806 - Jul 11, 08:01 UTCJul 11, 14:10 UTC6h 10m
2026-07-11 UAL1806 HNL → DEN Jul 11, 07:59 UTCJul 11, 14:09 UTC6h 10m
2026-07-10 UAL1805 - Jul 10, 22:45 UTCJul 11, 05:45 UTC7h 0m
2026-07-10 UAL1805 DEN → HNL Jul 10, 22:32 UTCJul 11, 05:45 UTC7h 13m
2026-07-10 UAL1806 HNL → DEN Jul 10, 10:20 UTCJul 10, 16:20 UTC6h 0m
2026-07-10 UAL1805 - Jul 10, 04:35 UTCJul 10, 04:50 UTC15m
2026-07-09 UAL1805 DEN → HNL Jul 9, 22:23 UTCJul 10, 04:46 UTC6h 23m
2026-07-09 UAL1805 - Jul 9, 22:15 UTCJul 10, 00:20 UTC2h 5m
2026-07-09 UAL1806 - Jul 9, 12:10 UTCJul 9, 14:10 UTC2h 0m
2026-07-09 UAL1806 - Jul 9, 08:00 UTCJul 9, 08:10 UTC10m
2026-07-09 UAL1170 - Jul 9, 00:45 UTCJul 9, 05:55 UTC5h 10m
2026-07-09 UAL1170 LAX → HNL Jul 9, 00:21 UTCJul 9, 05:54 UTC5h 33m
2026-07-07 UAL1157 BOS → IAD Jul 7, 23:25 UTCJul 8, 04:00 UTC4h 35m
2026-07-06 UAL253 - Jul 6, 23:00 UTCJul 6, 23:10 UTC10m
2026-07-06 UAL253 - Jul 6, 15:35 UTCJul 6, 19:10 UTC3h 35m
2026-07-06 UAL252 HNL → IAH Jul 6, 06:08 UTCJul 6, 13:04 UTC6h 56m
2026-07-05 UAL384 DEN → HNL Jul 5, 18:23 UTCJul 6, 00:56 UTC6h 33m
2026-07-05 UAL384 DEN → HNL Jul 5, 18:20 UTCJul 5, 19:00 UTC40m
2026-07-04 UAL1735 - Jul 4, 09:50 UTCJul 4, 12:00 UTC2h 10m
2026-07-04 UAL1735 OGG → DEN Jul 4, 06:15 UTCJul 4, 11:55 UTC5h 40m
2026-07-03 UAL1736 - Jul 3, 18:15 UTCJul 3, 20:30 UTC2h 15m
2026-07-02 UAL1806 - Jul 2, 08:05 UTCJul 2, 08:25 UTC20m
2026-07-02 UAL1806 HNL → DEN Jul 2, 07:59 UTCJul 2, 13:57 UTC5h 58m
2026-07-01 UAL1805 - Jul 1, 22:30 UTCJul 2, 05:20 UTC6h 50m
2026-07-01 UAL1806 - Jul 1, 12:35 UTCJul 1, 14:30 UTC1h 55m
2026-07-01 UAL1806 - Jul 1, 08:35 UTCJul 1, 08:55 UTC20m
2026-07-01 UAL1806 HNL → DEN Jul 1, 08:35 UTCJul 1, 14:25 UTC5h 50m
2026-07-01 UAL1805 DEN → HNL Jul 1, 00:08 UTCJul 1, 06:43 UTC6h 35m
2026-07-01 UAL1805 DEN → HNL Jul 1, 00:00 UTCJul 1, 06:50 UTC6h 50m
2026-06-29 UAL1735 - Jun 29, 10:04 UTCJun 29, 11:55 UTC1h 50m
2026-06-28 UAL1736 - Jun 28, 18:25 UTCJun 28, 20:54 UTC2h 30m
2026-06-28 UAL1806 - Jun 28, 08:05 UTCJun 28, 14:14 UTC6h 10m
2026-06-28 UAL1805 - Jun 28, 05:15 UTCJun 28, 05:40 UTC25m
2026-06-27 UAL1805 - Jun 27, 23:00 UTCJun 28, 01:15 UTC2h 15m
2026-06-27 UAL1735 - Jun 27, 10:19 UTCJun 27, 12:19 UTC2h 0m
2026-06-26 UAL1736 - Jun 26, 18:49 UTCJun 26, 21:15 UTC2h 25m
2026-06-26 UAL1806 - Jun 26, 08:05 UTCJun 26, 14:29 UTC6h 25m
2026-06-25 UAL1805 DEN → HNL Jun 25, 22:23 UTCJun 26, 04:53 UTC6h 30m
2026-06-25 UAL1805 - Jun 25, 22:20 UTCJun 26, 04:50 UTC6h 30m
2026-06-24 UAL1736 DEN → DEN Jun 24, 18:20 UTCJun 25, 11:54 UTC17h 35m
2026-06-24 UAL383 HNL → DEN Jun 24, 06:20 UTCJun 24, 12:25 UTC6h 5m
2026-06-23 UAL384 DEN → HNL Jun 23, 18:43 UTCJun 24, 01:21 UTC6h 38m
2026-06-23 UAL384 DEN → HNL Jun 23, 18:29 UTCJun 24, 00:59 UTC6h 30m
2026-06-22 UAL383 - Jun 22, 06:45 UTCJun 22, 12:40 UTC5h 55m

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 N211UA page for operator, model, and routing details .

Mode-S A1BEFC frequently asked

What is Mode-S code A1BEFC?
A1BEFC is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N211UA.
Where is Mode-S A1BEFC registered?
Mode-S code A1BEFC 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 A1BEFC broadcasting right now?
Yes. Mode-S A1BEFC is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A1BEFC, octal 50337374, decimal 10,600,188.
What flights does A1BEFC operate?
Mode-S A1BEFC has broadcast 20 distinct callsigns, including UAL1805, UAL1806, UAL1736, UAL384, UAL383.