Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A8D3B4

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N668UA · BOEING 767-300 · operated by UNITED AIRLINES INC

Hex
A8D3B4
Octal
52151664
Decimal
11,064,244
Country
US
Tail
N668UA
Type
B763
No current signal · last broadcast 1h ago
Flights observed
250
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S A8D3B4.

Country allocation

The ICAO 24-bit address A8D3B4 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
UAL273 - 16 2026-06-16
UAL965 - 15 2026-07-09
UAL962 - 11 2026-07-13
UAL272 - 11 2026-06-16
UAL16 - 11 2026-07-09
UAL147 - 11 2026-07-02
UAL928 United Airlines 10 2026-07-05
UAL3 - 9 2026-07-12
UAL964 - 8 2026-07-08
UAL963 - 8 2026-07-03
UAL929 - 8 2026-07-07
UAL921 - 8 2026-07-10
UAL134 - 8 2026-06-28
UAL12 - 8 2026-07-07
UAL959 - 7 2026-06-26
UAL941 - 7 2026-07-04
UAL54 United Airlines 7 2026-04-23
UAL956 - 6 2026-06-22
UAL938 United Airlines 6 2026-05-29
UAL55 United Airlines 6 2026-04-23

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-13 UAL962 - Jul 13, 21:50 UTCJul 14, 05:00 UTC7h 10m
2026-07-13 UAL135 ZRH → EWR Jul 13, 08:30 UTCJul 13, 16:50 UTC8h 20m
2026-07-12 UAL3 ORD → ZRH Jul 12, 21:32 UTCJul 13, 05:26 UTC7h 54m
2026-07-12 UAL3 - Jul 12, 21:10 UTCJul 13, 05:01 UTC7h 50m
2026-07-12 UAL958 LHR → ORD Jul 12, 07:31 UTCJul 12, 15:35 UTC8h 5m
2026-07-11 UAL934 EWR → LHR Jul 11, 13:25 UTCJul 11, 19:35 UTC6h 10m
2026-07-10 UAL921 - Jul 10, 17:40 UTCJul 11, 01:00 UTC7h 20m
2026-07-09 UAL16 - Jul 9, 22:15 UTCJul 10, 04:35 UTC6h 20m
2026-07-09 UAL965 - Jul 9, 08:00 UTCJul 9, 17:10 UTC9h 10m
2026-07-08 UAL964 - Jul 8, 20:40 UTCJul 9, 04:40 UTC8h 0m
2026-07-08 UAL17 - Jul 8, 10:35 UTCJul 8, 17:45 UTC7h 10m
2026-07-07 UAL929 - Jul 7, 22:15 UTCJul 7, 23:00 UTC45m
2026-07-07 UAL929 ORD → LHR Jul 7, 22:03 UTCJul 8, 05:40 UTC7h 37m
2026-07-07 UAL12 ZRH → ORD Jul 7, 08:25 UTCJul 7, 17:15 UTC8h 50m
2026-07-06 UAL3 LAX → HNL Jul 6, 21:32 UTCJul 7, 05:39 UTC8h 7m
2026-07-06 UAL3 LAX → HNL Jul 6, 21:30 UTCJul 6, 23:55 UTC2h 25m
2026-07-05 UAL928 LHR → ORD Jul 5, 21:45 UTCJul 5, 21:50 UTC5m
2026-07-05 UAL928 LHR → ORD Jul 5, 13:35 UTCJul 5, 21:50 UTC8h 15m
2026-07-05 UAL928 LHR → ORD Jul 5, 13:34 UTCJul 5, 21:29 UTC7h 55m
2026-07-05 UAL146 - Jul 5, 02:55 UTCJul 5, 04:25 UTC1h 30m
2026-07-05 UAL146 EWR → LHR Jul 5, 02:29 UTCJul 5, 09:01 UTC6h 32m
2026-07-04 UAL941 - Jul 4, 15:15 UTCJul 4, 16:35 UTC1h 20m
2026-07-04 UAL941 LHR → EWR Jul 4, 15:24 UTCJul 4, 22:44 UTC7h 20m
2026-07-04 UAL146 - Jul 4, 04:45 UTCJul 4, 11:10 UTC6h 25m
2026-07-03 UAL963 BER → EWR Jul 3, 08:05 UTCJul 3, 16:45 UTC8h 40m
2026-07-02 UAL962 EWR → BER Jul 2, 21:55 UTCJul 3, 04:55 UTC7h 0m
2026-07-02 UAL147 - Jul 2, 11:20 UTCJul 2, 12:35 UTC1h 15m
2026-07-02 UAL147 LHR → EWR Jul 2, 11:25 UTCJul 2, 19:04 UTC7h 39m
2026-07-02 UAL940 EWR → LHR Jul 2, 02:15 UTCJul 2, 08:55 UTC6h 40m
2026-07-01 UAL941 - Jul 1, 15:35 UTCJul 1, 23:10 UTC7h 35m
2026-07-01 UAL941 LHR → EWR Jul 1, 15:24 UTCJul 1, 23:02 UTC7h 38m
2026-07-01 UAL904 EWR → LHR Jul 1, 01:20 UTCJul 1, 07:35 UTC6h 15m
2026-06-30 UAL381 BDL → SMF Jun 30, 07:55 UTCJun 30, 17:10 UTC9h 15m
2026-06-29 UAL380 ORD → PDX Jun 29, 21:23 UTCJun 30, 05:08 UTC7h 45m
2026-06-29 UAL380 ORD → PDX Jun 29, 21:05 UTCJun 30, 05:05 UTC8h 1m
2026-06-29 UAL135 ZRH → EWR Jun 29, 08:54 UTCJun 29, 17:14 UTC8h 20m
2026-06-28 UAL134 EWR → ZRH Jun 28, 22:44 UTCJun 29, 06:15 UTC7h 31m
2026-06-28 UAL134 - Jun 28, 22:45 UTCJun 29, 00:29 UTC1h 45m
2026-06-28 UAL17 - Jun 28, 10:04 UTCJun 28, 17:25 UTC7h 20m
2026-06-28 UAL17 LHR → EWR Jun 28, 09:50 UTCJun 28, 17:26 UTC7h 36m
2026-06-27 UAL929 ORD → LHR Jun 27, 22:04 UTCJun 28, 05:29 UTC7h 25m
2026-06-26 UAL959 - Jun 26, 10:15 UTCJun 26, 18:44 UTC8h 30m
2026-06-26 UAL904 - Jun 26, 00:35 UTCJun 26, 06:45 UTC6h 10m
2026-06-25 UAL965 - Jun 25, 08:24 UTCJun 25, 11:19 UTC2h 55m
2026-06-25 UAL965 NAP → EWR Jun 25, 08:09 UTCJun 25, 17:44 UTC9h 35m
2026-06-24 UAL964 - Jun 24, 20:30 UTCJun 25, 04:20 UTC7h 50m
2026-06-24 UAL135 ZRH → EWR Jun 24, 08:30 UTCJun 24, 17:10 UTC8h 40m
2026-06-23 UAL134 EWR → ZRH Jun 23, 23:24 UTCJun 24, 06:29 UTC7h 5m
2026-06-23 UAL957 GVA → EWR Jun 23, 07:29 UTCJun 23, 08:59 UTC1h 30m
2026-06-23 UAL957 GVA → EWR Jun 23, 07:37 UTCJun 23, 15:54 UTC8h 17m

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 N668UA page for operator, model, and routing details .

Mode-S A8D3B4 frequently asked

What is Mode-S code A8D3B4?
A8D3B4 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N668UA.
Where is Mode-S A8D3B4 registered?
Mode-S code A8D3B4 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 A8D3B4 broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A8D3B4, octal 52151664, decimal 11,064,244.
What flights does A8D3B4 operate?
Mode-S A8D3B4 has broadcast 20 distinct callsigns, including UAL273, UAL965, UAL962, UAL272, UAL16.