Apparatus

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sensors Mode-S transponder

A8EC57

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N674UA · BOEING 767-300 · operated by UNITED AIRLINES INC

Hex
A8EC57
Octal
52166127
Decimal
11,070,551
Country
US
Tail
N674UA
Type
B763
Broadcasting now · callsign UAL965 · 29,000 ft
Flights observed
284
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 17:25 UTC

Current position

A8EC57 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A8EC57 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
UAL959 United Airlines 19 2026-07-22
UAL929 United Airlines 15 2026-07-19
UAL965 United Airlines 14 2026-07-21
UAL964 United Airlines 14 2026-07-20
UAL928 United Airlines 14 2026-07-18
UAL135 United Airlines 14 2026-07-25
UAL17 United Airlines 13 2026-07-20
UAL3 United Airlines 10 2026-07-24
UAL16 United Airlines 10 2026-07-23
UAL146 - 10 2026-07-12
UAL904 United Airlines 9 2026-07-22
UAL134 United Airlines 9 2026-07-25
UAL958 United Airlines 8 2026-07-24
UAL908 United Airlines 8 2026-05-19
UAL12 United Airlines 8 2026-07-26
UAL921 - 7 2026-07-09
UAL381 United Airlines 7 2026-06-14
UAL273 - 7 2026-06-28
UAL938 United Airlines 6 2026-07-18
UAL934 United Airlines 6 2026-06-23

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL12 HNL → LAX Jul 26, 08:19 UTCJul 26, 17:13 UTC8h 54m
2026-07-26 UAL12 HNL → LAX Jul 26, 08:15 UTCJul 26, 17:25 UTC9h 10m
2026-07-25 UAL134 EWR → ZRH Jul 25, 22:39 UTCJul 26, 05:46 UTC7h 7m
2026-07-25 UAL134 EWR → ZRH Jul 25, 22:45 UTCJul 26, 06:00 UTC7h 15m
2026-07-25 UAL135 ZRH → EWR Jul 25, 08:40 UTCJul 25, 16:58 UTC8h 18m
2026-07-25 UAL135 ZRH → EWR Jul 25, 08:50 UTCJul 25, 17:10 UTC8h 20m
2026-07-24 UAL3 LAX → HNL Jul 24, 21:25 UTCJul 25, 05:35 UTC8h 10m
2026-07-24 UAL3 LAX → HNL Jul 24, 21:32 UTCJul 25, 05:24 UTC7h 52m
2026-07-24 UAL958 ORD → LHR Jul 24, 07:20 UTCJul 24, 15:20 UTC8h 0m
2026-07-23 UAL16 EWR → LHR Jul 23, 23:00 UTCJul 24, 05:15 UTC6h 15m
2026-07-23 UAL135 ZRH → EWR Jul 23, 08:30 UTCJul 23, 16:25 UTC7h 55m
2026-07-23 UAL135 ZRH → EWR Jul 23, 08:20 UTCJul 23, 08:25 UTC5m
2026-07-22 UAL3 LAX → HNL Jul 22, 22:45 UTCJul 23, 05:45 UTC7h 0m
2026-07-22 UAL3 LAX → HNL Jul 22, 22:12 UTCJul 23, 06:36 UTC8h 24m
2026-07-22 UAL959 LHR → ORD Jul 22, 11:25 UTCJul 22, 18:50 UTC7h 25m
2026-07-22 UAL959 LHR → ORD Jul 22, 10:30 UTCJul 22, 18:31 UTC8h 1m
2026-07-22 UAL904 EWR → LHR Jul 22, 00:20 UTCJul 22, 06:42 UTC6h 22m
2026-07-22 UAL904 EWR → LHR Jul 22, 00:05 UTCJul 22, 05:25 UTC5h 20m
2026-07-21 UAL965 NAP → EWR Jul 21, 08:20 UTCJul 21, 17:40 UTC9h 20m
2026-07-20 UAL964 EWR → NAP Jul 20, 20:43 UTCJul 21, 05:10 UTC8h 27m
2026-07-20 UAL964 EWR → NAP Jul 20, 20:55 UTCJul 20, 21:45 UTC50m
2026-07-20 UAL17 LHR → EWR Jul 20, 09:55 UTCJul 20, 17:55 UTC8h 0m
2026-07-20 UAL17 LHR → EWR Jul 20, 09:50 UTCJul 20, 17:58 UTC8h 8m
2026-07-19 UAL929 ORD → LHR Jul 19, 22:40 UTCJul 20, 06:10 UTC7h 30m
2026-07-19 UAL959 LHR → ORD Jul 19, 10:35 UTCJul 19, 18:55 UTC8h 20m
2026-07-19 UAL920 ORD → LHR Jul 19, 01:15 UTCJul 19, 08:25 UTC7h 10m
2026-07-18 UAL928 LHR → ORD Jul 18, 13:44 UTCJul 18, 21:40 UTC7h 56m
2026-07-18 UAL928 LHR → ORD Jul 18, 13:55 UTCJul 18, 21:55 UTC8h 0m
2026-07-18 UAL938 ORD → LHR Jul 18, 03:13 UTCJul 18, 10:26 UTC7h 13m
2026-07-18 UAL938 ORD → LHR Jul 18, 03:05 UTCJul 18, 05:35 UTC2h 30m
2026-07-14 UAL928 - Jul 14, 21:50 UTCJul 14, 21:55 UTC5m
2026-07-14 UAL928 - Jul 14, 13:40 UTCJul 14, 21:55 UTC8h 15m
2026-07-14 UAL928 LHR → ORD Jul 14, 13:34 UTCJul 14, 21:35 UTC8h 1m
2026-07-14 UAL929 ORD → LHR Jul 14, 00:40 UTCJul 14, 08:30 UTC7h 50m
2026-07-13 UAL959 - Jul 13, 10:40 UTCJul 13, 18:30 UTC7h 50m
2026-07-13 UAL940 EWR → LHR Jul 13, 01:21 UTCJul 13, 08:04 UTC6h 43m
2026-07-13 UAL940 EWR → LHR Jul 13, 01:15 UTCJul 13, 08:05 UTC6h 50m
2026-07-12 UAL15 LHR → EWR Jul 12, 14:55 UTCJul 12, 22:05 UTC7h 10m
2026-07-12 UAL146 EWR → LHR Jul 12, 02:29 UTCJul 12, 09:03 UTC6h 34m
2026-07-12 UAL146 - Jul 12, 02:30 UTCJul 12, 03:45 UTC1h 15m
2026-07-09 UAL921 - Jul 9, 20:00 UTCJul 9, 21:15 UTC1h 15m
2026-07-09 UAL921 LHR → EWR Jul 9, 19:53 UTCJul 10, 03:28 UTC7h 35m
2026-07-09 UAL921 LHR → EWR Jul 9, 19:53 UTCJul 10, 03:04 UTC7h 11m
2026-07-09 UAL920 ORD → LHR Jul 9, 00:20 UTCJul 9, 07:45 UTC7h 25m
2026-07-08 UAL959 - Jul 8, 10:40 UTCJul 8, 18:50 UTC8h 10m
2026-07-08 UAL904 EWR → LHR Jul 8, 00:20 UTCJul 8, 06:58 UTC6h 38m
2026-07-08 UAL904 EWR → LHR Jul 8, 00:15 UTCJul 8, 07:05 UTC6h 50m
2026-07-07 UAL135 ZRH → EWR Jul 7, 13:20 UTCJul 7, 21:34 UTC8h 14m
2026-07-07 UAL135 ZRH → EWR Jul 7, 13:10 UTCJul 7, 21:35 UTC8h 25m
2026-07-07 UAL134 - Jul 7, 03:15 UTCJul 7, 04:50 UTC1h 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 N674UA page for operator, model, and routing details .

Mode-S A8EC57 frequently asked

What is Mode-S code A8EC57?
A8EC57 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N674UA.
Where is Mode-S A8EC57 registered?
Mode-S code A8EC57 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 A8EC57 broadcasting right now?
Yes. Mode-S A8EC57 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A8EC57, octal 52166127, decimal 11,070,551.
What flights does A8EC57 operate?
Mode-S A8EC57 has broadcast 20 distinct callsigns, including UAL959, UAL929, UAL965, UAL964, UAL928.