Apparatus

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sensors Mode-S transponder

A8856D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N64809 · BOEING 737-900 · operated by UNITED AIRLINES INC

Hex
A8856D
Octal
52102555
Decimal
11,044,205
Country
US
Tail
N64809
Type
B739
No current signal · last broadcast Jul 26, 21:15 UTC
Flights observed
411
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:15 UTC

Last known position

Most recent position reported by Mode-S A8856D.

Country allocation

The ICAO 24-bit address A8856D 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
UAL703 - 4 2026-07-20
UAL677 - 4 2026-07-03
UAL663 - 4 2026-06-19
UAL2741 United Airlines 4 2026-06-05
UAL2685 United Airlines 4 2026-05-06
UAL1864 - 4 2026-07-17
UAL1686 United Airlines 4 2026-07-19
UAL1640 United Airlines 4 2026-05-02
UAL1516 United Airlines 4 2026-06-03
UAL1196 United Airlines 4 2026-05-15
UAL1101 United Airlines 4 2026-06-30
UAL733 - 3 2026-07-12
UAL395 - 3 2026-06-26
UAL370 - 3 2026-07-17
UAL361 United Airlines 3 2026-07-23
UAL2793 - 3 2026-07-20
UAL2310 United Airlines 3 2026-06-08
UAL2242 United Airlines 3 2026-06-14
UAL2136 - 3 2026-07-12
UAL1957 - 3 2026-07-11

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL2029 ORD → RIC Jul 26, 16:30 UTCJul 26, 21:15 UTC4h 45m
2026-07-26 UAL1301 CLT → ORD Jul 26, 12:05 UTCJul 26, 14:10 UTC2h 5m
2026-07-26 UAL301 ORD → DSM Jul 26, 04:25 UTCJul 26, 06:20 UTC1h 55m
2026-07-25 UAL2142 MSY → EWR Jul 25, 22:10 UTCJul 26, 02:15 UTC4h 5m
2026-07-25 UAL499 DEN → EWR Jul 25, 16:40 UTCJul 25, 20:30 UTC3h 50m
2026-07-25 UAL2830 IAH → SFO Jul 25, 13:50 UTCJul 25, 14:45 UTC55m
2026-07-25 UAL1343 EWR → TPA Jul 25, 03:00 UTCJul 25, 04:15 UTC1h 15m
2026-07-24 UAL589 DEN → RIC Jul 24, 21:40 UTCJul 25, 01:10 UTC3h 30m
2026-07-24 UAL470 - Jul 24, 16:40 UTCJul 24, 18:40 UTC2h 0m
2026-07-24 UAL1966 MSY → EWR Jul 24, 12:50 UTCJul 24, 14:55 UTC2h 5m
2026-07-24 UAL505 SFO → IAH Jul 24, 07:50 UTCJul 24, 11:15 UTC3h 25m
2026-07-24 UAL1273 SFO → OGG Jul 24, 02:55 UTCJul 24, 05:55 UTC3h 0m
2026-07-23 UAL414 EWR → SFO Jul 23, 22:40 UTCJul 24, 00:05 UTC1h 25m
2026-07-23 UAL1195 DTW → ORD Jul 23, 19:00 UTCJul 23, 20:15 UTC1h 15m
2026-07-23 UAL361 DEN → BOS Jul 23, 16:35 UTCJul 23, 17:40 UTC1h 5m
2026-07-23 UAL1666 - Jul 23, 12:10 UTCJul 23, 14:45 UTC2h 35m
2026-07-23 UAL8104 YUL → YFC Jul 23, 03:08 UTCJul 23, 05:19 UTC2h 11m
2026-07-23 UAL8104 YUL → YFC Jul 23, 03:05 UTCJul 23, 05:25 UTC2h 20m
2026-07-22 UAL1255 MCI → EWR Jul 22, 22:35 UTCJul 23, 00:30 UTC1h 55m
2026-07-22 UAL1255 MCI → EWR Jul 22, 22:37 UTCJul 23, 00:28 UTC1h 51m
2026-07-22 UAL295 DEN → GEG Jul 22, 18:02 UTCJul 22, 19:36 UTC1h 34m
2026-07-22 UAL295 DEN → GEG Jul 22, 17:45 UTCJul 22, 19:40 UTC1h 55m
2026-07-21 UAL479 CVG → DEN Jul 21, 23:15 UTCJul 22, 01:40 UTC2h 25m
2026-07-21 UAL1978 DEN → CVG Jul 21, 19:55 UTCJul 21, 22:00 UTC2h 5m
2026-07-20 UAL478 - Jul 20, 20:35 UTCJul 20, 22:05 UTC1h 30m
2026-07-20 UAL703 - Jul 20, 18:00 UTCJul 20, 19:05 UTC1h 5m
2026-07-20 UAL280 - Jul 20, 14:45 UTCJul 20, 16:00 UTC1h 15m
2026-07-20 UAL2793 - Jul 20, 00:25 UTCJul 20, 01:40 UTC1h 15m
2026-07-19 UAL1615 CLE → SFO Jul 19, 21:00 UTCJul 19, 22:35 UTC1h 35m
2026-07-19 UAL1686 IAH → SNA Jul 19, 17:50 UTCJul 19, 19:05 UTC1h 15m
2026-07-19 UAL703 - Jul 19, 14:25 UTCJul 19, 16:20 UTC1h 55m
2026-07-19 UAL1971 EWR → SAT Jul 19, 02:15 UTCJul 19, 02:55 UTC40m
2026-07-18 UAL716 CHS → DEN Jul 18, 22:20 UTCJul 18, 23:45 UTC1h 25m
2026-07-18 UAL2793 PDX → DEN Jul 18, 18:20 UTCJul 18, 20:25 UTC2h 5m
2026-07-18 UAL1247 DEN → PDX Jul 18, 14:30 UTCJul 18, 16:45 UTC2h 15m
2026-07-18 UAL1442 - Jul 18, 11:15 UTCJul 18, 12:20 UTC1h 5m
2026-07-18 UAL1625 ORD → OMA Jul 18, 04:45 UTCJul 18, 05:45 UTC1h 0m
2026-07-17 UAL1686 PHX → ORD Jul 17, 23:37 UTCJul 18, 02:26 UTC2h 49m
2026-07-17 UAL1686 - Jul 17, 23:35 UTCJul 18, 03:00 UTC3h 26m
2026-07-17 UAL370 - Jul 17, 15:29 UTCJul 17, 20:00 UTC4h 30m
2026-07-17 UAL1864 - Jul 17, 11:39 UTCJul 17, 14:04 UTC2h 25m
2026-07-17 UAL1864 MIA → EWR Jul 17, 11:22 UTCJul 17, 14:02 UTC2h 40m
2026-07-17 UAL1128 SFO → EWR Jul 17, 00:55 UTCJul 17, 03:30 UTC2h 35m
2026-07-16 UAL1051 CUN → EWR Jul 16, 18:44 UTCJul 16, 22:25 UTC3h 40m
2026-07-16 UAL1018 - Jul 16, 15:30 UTCJul 16, 17:14 UTC1h 45m
2026-07-16 UAL2665 - Jul 16, 03:20 UTCJul 16, 05:25 UTC2h 5m
2026-07-16 UAL2665 ORD → IAH Jul 16, 03:13 UTCJul 16, 05:25 UTC2h 12m
2026-07-15 UAL1686 - Jul 15, 22:05 UTCJul 16, 01:15 UTC3h 10m
2026-07-15 UAL370 EWR → PHX Jul 15, 15:35 UTCJul 15, 19:45 UTC4h 10m
2026-07-15 UAL1864 - Jul 15, 11:15 UTCJul 15, 13:50 UTC2h 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 N64809 page for operator, model, and routing details .

Mode-S A8856D frequently asked

What is Mode-S code A8856D?
A8856D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N64809.
Where is Mode-S A8856D registered?
Mode-S code A8856D 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 A8856D broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 21:15 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A8856D, octal 52102555, decimal 11,044,205.
What flights does A8856D operate?
Mode-S A8856D has broadcast 20 distinct callsigns, including UAL703, UAL677, UAL663, UAL2741, UAL2685.