Apparatus

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sensors Mode-S transponder

A8CFFD

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N667UA · BOEING 767-300 · operated by UNITED AIRLINES INC

Hex
A8CFFD
Octal
52147775
Decimal
11,063,293
Country
US
Tail
N667UA
Type
B763
No current signal · last broadcast Jul 26, 16:40 UTC
Flights observed
253
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 16:40 UTC

Last known position

Most recent position reported by Mode-S A8CFFD.

Country allocation

The ICAO 24-bit address A8CFFD 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
UAL928 - 14 2026-07-13
UAL921 - 12 2026-07-20
UAL273 - 12 2026-07-18
UAL938 - 11 2026-07-14
UAL965 - 10 2026-06-30
UAL381 United Airlines 10 2026-07-26
UAL272 United Airlines 10 2026-07-18
UAL17 United Airlines 10 2026-07-24
UAL920 United Airlines 9 2026-07-24
UAL904 - 9 2026-07-10
UAL964 - 8 2026-06-29
UAL16 United Airlines 8 2026-07-19
UAL122 United Airlines 8 2026-04-29
UAL959 - 7 2026-07-06
UAL958 - 7 2026-07-07
UAL380 United Airlines 7 2026-07-25
UAL940 - 6 2026-06-26
UAL15 - 6 2026-06-14
UAL147 - 6 2026-07-08
UAL12 United Airlines 6 2026-07-23

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL381 BDL → SMF Jul 26, 15:45 UTCJul 26, 16:35 UTC50m
2026-07-26 UAL381 BDL → SMF Jul 26, 07:15 UTCJul 26, 15:40 UTC8h 25m
2026-07-25 UAL380 ORD → PDX Jul 25, 19:50 UTCJul 26, 03:50 UTC8h 0m
2026-07-25 UAL957 GVA → EWR Jul 25, 07:30 UTCJul 25, 15:25 UTC7h 55m
2026-07-24 UAL956 EWR → GVA Jul 24, 21:45 UTCJul 25, 04:55 UTC7h 10m
2026-07-24 UAL17 LHR → EWR Jul 24, 09:50 UTCJul 24, 11:05 UTC1h 15m
2026-07-24 UAL17 LHR → EWR Jul 24, 09:40 UTCJul 24, 17:00 UTC7h 20m
2026-07-24 UAL17 LHR → EWR Jul 24, 09:40 UTCJul 24, 17:00 UTC7h 20m
2026-07-24 UAL920 ORD → LHR Jul 24, 00:05 UTCJul 24, 07:25 UTC7h 20m
2026-07-23 UAL920 ORD → LHR Jul 23, 23:57 UTCJul 24, 07:19 UTC7h 22m
2026-07-23 UAL12 HNL → LAX Jul 23, 10:15 UTCJul 23, 19:25 UTC9h 10m
2026-07-23 UAL134 EWR → ZRH Jul 23, 00:50 UTCJul 23, 08:05 UTC7h 15m
2026-07-20 UAL921 - Jul 20, 17:35 UTCJul 21, 00:50 UTC7h 15m
2026-07-20 UAL921 LHR → EWR Jul 20, 17:22 UTCJul 21, 00:44 UTC7h 22m
2026-07-19 UAL16 EWR → LHR Jul 19, 21:58 UTCJul 20, 05:14 UTC7h 16m
2026-07-19 UAL16 EWR → LHR Jul 19, 22:30 UTCJul 20, 05:15 UTC6h 45m
2026-07-18 UAL273 NCE → EWR Jul 18, 12:15 UTCJul 18, 20:35 UTC8h 20m
2026-07-18 UAL273 NCE → EWR Jul 18, 12:15 UTCJul 18, 20:33 UTC8h 18m
2026-07-18 UAL272 EWR → NCE Jul 18, 00:50 UTCJul 18, 08:20 UTC7h 31m
2026-07-17 UAL967 - Jul 17, 12:45 UTCJul 17, 13:15 UTC30m
2026-07-17 UAL967 NAP → EWR Jul 17, 12:24 UTCJul 17, 21:44 UTC9h 20m
2026-07-17 UAL966 - Jul 17, 01:45 UTCJul 17, 09:50 UTC8h 5m
2026-07-15 UAL921 - Jul 15, 17:25 UTCJul 15, 18:35 UTC1h 10m
2026-07-15 UAL921 LHR → EWR Jul 15, 17:22 UTCJul 16, 00:35 UTC7h 13m
2026-07-15 UAL146 EWR → LHR Jul 15, 02:20 UTCJul 15, 09:10 UTC6h 50m
2026-07-14 UAL941 - Jul 14, 15:25 UTCJul 14, 22:40 UTC7h 15m
2026-07-14 UAL938 ORD → LHR Jul 14, 03:55 UTCJul 14, 11:35 UTC7h 40m
2026-07-13 UAL928 - Jul 13, 21:50 UTCJul 13, 22:00 UTC10m
2026-07-13 UAL928 - Jul 13, 13:45 UTCJul 13, 22:00 UTC8h 15m
2026-07-13 UAL928 LHR → ORD Jul 13, 13:34 UTCJul 13, 21:32 UTC7h 58m
2026-07-13 UAL938 ORD → LHR Jul 13, 03:55 UTCJul 13, 11:20 UTC7h 25m
2026-07-12 UAL12 ZRH → ORD Jul 12, 08:15 UTCJul 12, 17:15 UTC9h 0m
2026-07-12 UAL3 - Jul 12, 03:10 UTCJul 12, 05:20 UTC2h 10m
2026-07-11 UAL3 - Jul 11, 21:15 UTCJul 11, 23:40 UTC2h 25m
2026-07-11 UAL12 ZRH → ORD Jul 11, 08:10 UTCJul 11, 17:10 UTC9h 0m
2026-07-10 UAL134 - Jul 10, 23:05 UTCJul 11, 06:15 UTC7h 10m
2026-07-10 UAL17 LHR → EWR Jul 10, 10:05 UTCJul 10, 17:35 UTC7h 30m
2026-07-10 UAL904 EWR → LHR Jul 10, 00:25 UTCJul 10, 06:39 UTC6h 14m
2026-07-10 UAL904 - Jul 10, 00:15 UTCJul 10, 01:15 UTC1h 0m
2026-07-09 UAL273 - Jul 9, 10:25 UTCJul 9, 11:15 UTC50m
2026-07-09 UAL273 NCE → EWR Jul 9, 10:30 UTCJul 9, 18:52 UTC8h 22m
2026-07-09 UAL272 - Jul 9, 00:10 UTCJul 9, 07:50 UTC7h 40m
2026-07-08 UAL147 LHR → EWR Jul 8, 11:25 UTCJul 8, 18:30 UTC7h 5m
2026-07-08 UAL920 ORD → LHR Jul 8, 00:25 UTCJul 8, 08:10 UTC7h 45m
2026-07-07 UAL958 - Jul 7, 07:35 UTCJul 7, 15:40 UTC8h 5m
2026-07-06 UAL929 ORD → LHR Jul 6, 22:20 UTCJul 7, 05:45 UTC7h 25m
2026-07-06 UAL959 - Jul 6, 10:45 UTCJul 6, 18:55 UTC8h 10m
2026-07-06 UAL904 EWR → LHR Jul 6, 00:35 UTCJul 6, 06:37 UTC6h 2m
2026-07-06 UAL904 EWR → LHR Jul 6, 00:30 UTCJul 6, 06:40 UTC6h 10m
2026-07-05 UAL957 GVA → EWR Jul 5, 07:25 UTCJul 5, 09:15 UTC1h 50m

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 N667UA page for operator, model, and routing details .

Mode-S A8CFFD frequently asked

What is Mode-S code A8CFFD?
A8CFFD is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N667UA.
Where is Mode-S A8CFFD registered?
Mode-S code A8CFFD 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 A8CFFD broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 16:40 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A8CFFD, octal 52147775, decimal 11,063,293.
What flights does A8CFFD operate?
Mode-S A8CFFD has broadcast 20 distinct callsigns, including UAL928, UAL921, UAL273, UAL938, UAL965.