Apparatus

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sensors Mode-S transponder

AA931D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N78013 · BOEING 777-200 · operated by UNITED AIRLINES INC

Hex
AA931D
Octal
52511435
Decimal
11,178,781
Country
US
Tail
N78013
Type
B772
No current signal · last broadcast 1h ago
Flights observed
190
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S AA931D.

Country allocation

The ICAO 24-bit address AA931D 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
UAL888 United Airlines 9 2026-06-08
UAL875 - 9 2026-07-06
UAL131 United Airlines 9 2026-06-04
UAL889 United Airlines 7 2026-06-09
UAL876 United Airlines 7 2026-06-05
UAL948 United Airlines 6 2026-06-06
UAL926 - 6 2026-07-13
UAL149 - 6 2026-07-09
UAL130 - 6 2026-06-28
UAL933 - 5 2026-07-13
UAL506 United Airlines 5 2026-04-15
UAL45 - 5 2026-07-12
UAL44 - 5 2026-07-11
UAL984 - 4 2026-06-23
UAL885 - 4 2026-06-26
UAL852 - 4 2026-07-02
UAL837 United Airlines 4 2026-04-18
UAL804 - 4 2026-07-07
UAL803 United Airlines 4 2026-06-27
UAL195 United Airlines 4 2026-04-13

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 UAL932 - Jul 14, 02:40 UTCJul 14, 04:45 UTC2h 5m
2026-07-13 UAL933 FRA → IAD Jul 13, 15:40 UTCJul 13, 23:30 UTC7h 50m
2026-07-13 UAL926 SFO → FRA Jul 13, 02:55 UTCJul 13, 13:15 UTC10h 20m
2026-07-12 UAL45 ZRH → SFO Jul 12, 12:02 UTCJul 12, 23:44 UTC11h 42m
2026-07-12 UAL45 - Jul 12, 12:20 UTCJul 12, 23:50 UTC11h 30m
2026-07-11 UAL44 SFO → ZRH Jul 11, 21:48 UTCJul 12, 07:43 UTC9h 55m
2026-07-11 UAL44 - Jul 11, 21:40 UTCJul 11, 23:00 UTC1h 20m
2026-07-10 UAL1593 EWR → SFO Jul 10, 15:29 UTCJul 10, 20:20 UTC4h 51m
2026-07-10 UAL1593 - Jul 10, 15:15 UTCJul 10, 19:15 UTC4h 0m
2026-07-10 UAL148 - Jul 10, 00:45 UTCJul 10, 09:40 UTC8h 55m
2026-07-09 UAL149 - Jul 9, 09:35 UTCJul 9, 10:25 UTC50m
2026-07-09 UAL149 EWR → GRU Jul 9, 02:11 UTCJul 9, 10:25 UTC8h 14m
2026-07-09 UAL149 - Jul 9, 01:55 UTCJul 9, 02:30 UTC35m
2026-07-08 UAL56 - Jul 8, 08:30 UTCJul 8, 16:00 UTC7h 30m
2026-07-07 UAL915 IAD → CDG Jul 7, 22:40 UTCJul 8, 05:35 UTC6h 55m
2026-07-07 UAL804 HND → IAD Jul 7, 07:10 UTCJul 7, 19:21 UTC12h 11m
2026-07-07 UAL804 HND → IAD Jul 7, 06:55 UTCJul 7, 19:25 UTC12h 30m
2026-07-06 UAL875 SFO → HND Jul 6, 18:25 UTCJul 7, 04:32 UTC10h 7m
2026-07-06 UAL875 - Jul 6, 18:15 UTCJul 6, 18:45 UTC30m
2026-07-06 UAL916 AKL → SFO Jul 6, 02:15 UTCJul 6, 13:30 UTC11h 15m
2026-07-05 UAL917 SFO → AKL Jul 5, 06:30 UTCJul 5, 18:50 UTC12h 20m
2026-07-04 UAL927 - Jul 4, 16:05 UTCJul 5, 03:25 UTC11h 20m
2026-07-04 UAL926 SFO → FRA Jul 4, 02:44 UTCJul 4, 12:45 UTC10h 1m
2026-07-04 UAL926 SFO → FRA Jul 4, 02:40 UTCJul 4, 12:50 UTC10h 10m
2026-07-03 UAL45 ZRH → SFO Jul 3, 12:02 UTCJul 3, 23:08 UTC11h 6m
2026-07-03 UAL45 - Jul 3, 11:55 UTCJul 3, 14:10 UTC2h 15m
2026-07-02 UAL44 SFO → ZRH Jul 2, 22:00 UTCJul 3, 08:15 UTC10h 15m
2026-07-02 UAL852 - Jul 2, 08:10 UTCJul 2, 17:40 UTC9h 30m
2026-07-02 UAL852 TPE → SFO Jul 2, 06:51 UTCJul 2, 17:36 UTC10h 45m
2026-07-02 UAL852 TPE → SFO Jul 2, 06:51 UTCJul 2, 17:33 UTC10h 42m
2026-07-02 UAL852 - Jul 2, 06:41 UTCJul 2, 07:00 UTC19m
2026-07-01 UAL853 - Jul 1, 19:25 UTCJul 1, 19:45 UTC20m
2026-07-01 UAL853 SFO → TPE Jul 1, 07:26 UTCJul 1, 19:48 UTC12h 22m
2026-07-01 UAL853 - Jul 1, 07:20 UTCJul 1, 07:50 UTC30m
2026-06-30 UAL2328 - Jun 30, 19:10 UTCJul 1, 00:15 UTC5h 5m
2026-06-30 UAL148 - Jun 30, 00:14 UTCJun 30, 09:15 UTC9h 1m
2026-06-29 UAL149 - Jun 29, 01:34 UTCJun 29, 10:10 UTC8h 35m
2026-06-28 UAL130 HND → EWR Jun 28, 09:34 UTCJun 28, 21:24 UTC11h 50m
2026-06-28 UAL130 HND → EWR Jun 28, 09:30 UTCJun 28, 21:18 UTC11h 48m
2026-06-27 UAL803 IAD → HND Jun 27, 17:14 UTCJun 28, 06:55 UTC13h 40m
2026-06-26 UAL885 - Jun 26, 08:45 UTCJun 26, 11:09 UTC2h 25m
2026-06-26 UAL885 FCO → IAD Jun 26, 08:47 UTCJun 26, 17:25 UTC8h 38m
2026-06-25 UAL884 IAD → FCO Jun 25, 22:08 UTCJun 26, 06:05 UTC7h 57m
2026-06-25 UAL884 - Jun 25, 22:10 UTCJun 25, 23:14 UTC1h 5m
2026-06-25 UAL885 - Jun 25, 08:55 UTCJun 25, 18:10 UTC9h 15m
2026-06-25 UAL885 FCO → IAD Jun 25, 08:47 UTCJun 25, 18:07 UTC9h 20m
2026-06-24 UAL884 IAD → FCO Jun 24, 22:19 UTCJun 25, 06:09 UTC7h 50m
2026-06-24 UAL914 CDG → IAD Jun 24, 11:05 UTCJun 24, 19:04 UTC8h 0m
2026-06-23 UAL990 SFO → CDG Jun 23, 22:29 UTCJun 24, 08:35 UTC10h 5m
2026-06-23 UAL984 - Jun 23, 08:09 UTCJun 23, 09:40 UTC1h 30m

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 N78013 page for operator, model, and routing details .

Mode-S AA931D frequently asked

What is Mode-S code AA931D?
AA931D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N78013.
Where is Mode-S AA931D registered?
Mode-S code AA931D 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 AA931D 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 AA931D, octal 52511435, decimal 11,178,781.
What flights does AA931D operate?
Mode-S AA931D has broadcast 20 distinct callsigns, including UAL888, UAL875, UAL131, UAL889, UAL876.