Apparatus

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sensors Mode-S transponder

A2B8FE

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N2749U · BOEING 777-300ER · operated by UNITED AIRLINES INC

Hex
A2B8FE
Octal
50534376
Decimal
10,664,190
Country
US
Tail
N2749U
Type
B77W
No current signal · last broadcast Jul 26, 14:05 UTC
Flights observed
247
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 14:05 UTC

Last known position

Most recent position reported by Mode-S A2B8FE.

Country allocation

The ICAO 24-bit address A2B8FE 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
UAL877 - 17 2026-06-30
UAL858 - 16 2026-07-11
UAL810 United Airlines 16 2026-07-26
UAL809 United Airlines 15 2026-07-25
UAL988 - 12 2026-07-22
UAL857 - 12 2026-07-10
UAL872 - 11 2026-07-06
UAL862 - 11 2026-07-01
UAL838 - 11 2026-07-09
UAL869 - 10 2026-07-11
UAL878 - 9 2026-07-12
UAL871 - 9 2026-07-04
UAL989 United Airlines 8 2026-07-23
UAL42 United Airlines 8 2026-07-17
UAL951 United Airlines 7 2026-07-23
UAL950 United Airlines 7 2026-07-22
UAL837 United Airlines 7 2026-07-01
UAL79 - 7 2026-07-08
UAL2416 - 5 2026-07-08
UAL1175 - 5 2026-07-14

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL810 PHL → DEN Jul 26, 13:40 UTCJul 26, 14:05 UTC25m
2026-07-25 UAL809 SEA → IAD Jul 25, 21:55 UTCJul 26, 10:40 UTC12h 46m
2026-07-24 UAL1844 EWR → MIA Jul 24, 23:00 UTCJul 25, 04:15 UTC5h 15m
2026-07-24 UAL43 OGG → EWR Jul 24, 09:40 UTCJul 24, 17:50 UTC8h 10m
2026-07-23 UAL989 IAD → FRA Jul 23, 22:35 UTCJul 24, 05:30 UTC6h 55m
2026-07-23 UAL989 IAD → FRA Jul 23, 22:08 UTCJul 24, 05:15 UTC7h 7m
2026-07-23 UAL951 BRU → IAD Jul 23, 10:25 UTCJul 23, 18:05 UTC7h 40m
2026-07-22 UAL950 IAD → BRU Jul 22, 22:45 UTCJul 23, 05:30 UTC6h 45m
2026-07-22 UAL950 IAD → BRU Jul 22, 22:43 UTCJul 23, 05:37 UTC6h 54m
2026-07-22 UAL988 - Jul 22, 11:55 UTCJul 22, 20:00 UTC8h 5m
2026-07-22 UAL989 IAD → FRA Jul 22, 01:35 UTCJul 22, 03:30 UTC1h 55m
2026-07-21 UAL988 - Jul 21, 11:15 UTCJul 21, 13:10 UTC1h 55m
2026-07-21 UAL988 FRA → IAD Jul 21, 11:04 UTCJul 21, 19:16 UTC8h 12m
2026-07-20 UAL989 IAD → FRA Jul 20, 22:55 UTCJul 21, 05:30 UTC6h 34m
2026-07-20 UAL989 IAD → FRA Jul 20, 22:53 UTCJul 21, 05:51 UTC6h 58m
2026-07-20 UAL951 BRU → IAD Jul 20, 10:35 UTCJul 20, 18:10 UTC7h 35m
2026-07-19 UAL950 IAD → BRU Jul 19, 22:30 UTCJul 20, 05:45 UTC7h 15m
2026-07-18 UAL951 BRU → IAD Jul 18, 17:40 UTCJul 18, 18:45 UTC1h 5m
2026-07-18 UAL951 BRU → IAD Jul 18, 10:28 UTCJul 18, 18:39 UTC8h 11m
2026-07-18 UAL951 BRU → IAD Jul 18, 10:35 UTCJul 18, 17:35 UTC7h 0m
2026-07-17 UAL950 IAD → BRU Jul 17, 22:49 UTCJul 18, 05:55 UTC7h 6m
2026-07-17 UAL988 - Jul 17, 10:50 UTCJul 17, 12:40 UTC1h 50m
2026-07-17 UAL988 FRA → IAD Jul 17, 10:39 UTCJul 17, 18:45 UTC8h 6m
2026-07-17 UAL42 OGG → EWR Jul 17, 00:00 UTCJul 17, 07:25 UTC7h 25m
2026-07-17 UAL42 OGG → EWR Jul 17, 00:40 UTCJul 17, 05:30 UTC4h 50m
2026-07-16 UAL435 SFO → EWR Jul 16, 15:54 UTCJul 16, 20:37 UTC4h 43m
2026-07-16 UAL435 SFO → EWR Jul 16, 15:55 UTCJul 16, 20:39 UTC4h 45m
2026-07-16 UAL1346 - Jul 16, 08:35 UTCJul 16, 13:00 UTC4h 25m
2026-07-16 UAL1346 HNL → SFO Jul 16, 08:29 UTCJul 16, 12:54 UTC4h 25m
2026-07-16 UAL200 - Jul 16, 03:40 UTCJul 16, 04:05 UTC25m
2026-07-15 UAL201 - Jul 15, 01:00 UTCJul 15, 01:15 UTC15m
2026-07-15 UAL201 HNL → GUM Jul 15, 00:44 UTCJul 15, 07:52 UTC7h 8m
2026-07-14 UAL1175 - Jul 14, 21:15 UTCJul 14, 21:30 UTC15m
2026-07-14 UAL1175 - Jul 14, 16:45 UTCJul 14, 17:10 UTC25m
2026-07-14 UAL190 - Jul 14, 01:20 UTCJul 14, 13:50 UTC12h 30m
2026-07-13 UAL189 - Jul 13, 08:15 UTCJul 13, 21:20 UTC13h 5m
2026-07-12 UAL878 - Jul 12, 14:50 UTCJul 13, 03:20 UTC12h 30m
2026-07-11 UAL869 SFO → HKG Jul 11, 21:22 UTCJul 12, 10:37 UTC13h 15m
2026-07-11 UAL869 SFO → HKG Jul 11, 21:30 UTCJul 12, 10:40 UTC13h 10m
2026-07-11 UAL858 - Jul 11, 05:05 UTCJul 11, 06:40 UTC1h 35m
2026-07-11 UAL858 PVG → SFO Jul 11, 04:44 UTCJul 11, 15:19 UTC10h 35m
2026-07-10 UAL858 - Jul 10, 07:35 UTCJul 11, 06:40 UTC23h 5m
2026-07-10 UAL857 - Jul 10, 06:25 UTCJul 11, 05:31 UTC23h 6m
2026-07-09 UAL857 SFO → PVG Jul 9, 21:02 UTCJul 10, 09:07 UTC12h 5m
2026-07-09 UAL857 - Jul 9, 21:05 UTCJul 9, 21:30 UTC25m
2026-07-09 UAL838 - Jul 9, 08:30 UTCJul 9, 17:35 UTC9h 5m
2026-07-09 UAL838 NRT → SFO Jul 9, 08:31 UTCJul 9, 17:27 UTC8h 56m
2026-07-08 UAL79 EWR → NRT Jul 8, 16:02 UTCJul 9, 05:02 UTC13h 0m
2026-07-08 UAL79 - Jul 8, 16:00 UTCJul 8, 17:10 UTC1h 10m
2026-07-08 UAL2416 SFO → EWR Jul 8, 07:25 UTCJul 8, 12:00 UTC4h 35m

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 N2749U page for operator, model, and routing details .

Mode-S A2B8FE frequently asked

What is Mode-S code A2B8FE?
A2B8FE is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N2749U.
Where is Mode-S A2B8FE registered?
Mode-S code A2B8FE 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 A2B8FE broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 14:05 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A2B8FE, octal 50534376, decimal 10,664,190.
What flights does A2B8FE operate?
Mode-S A2B8FE has broadcast 20 distinct callsigns, including UAL877, UAL858, UAL810, UAL809, UAL988.