Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A27C78

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N25982 · BOEING 787-9 Dreamliner · operated by UNITED AIRLINES INC

Hex
A27C78
Octal
50476170
Decimal
10,648,696
Country
US
Tail
N25982
Type
B789
Broadcasting now · callsign UAL863 · 31,975 ft
Flights observed
86
Distinct callsigns
20
Country
US
Last broadcast
3h ago

Current position

A27C78 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A27C78 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
UAL29 United Airlines 5 2026-05-26
UAL187 United Airlines 5 2026-04-17
UAL1122 United Airlines 5 2026-06-01
UAL199 United Airlines 4 2026-04-25
UAL1321 United Airlines 4 2026-04-17
UAL893 United Airlines 3 2026-05-29
UAL821 United Airlines 3 2026-04-27
UAL820 United Airlines 3 2026-04-27
UAL806 United Airlines 3 2026-05-24
UAL805 United Airlines 3 2026-05-23
UAL78 United Airlines 3 2026-04-15
UAL61 United Airlines 3 2026-05-29
UAL60 United Airlines 3 2026-05-28
UAL32 United Airlines 3 2026-04-15
UAL28 United Airlines 3 2026-05-27
UAL2222 United Airlines 3 2026-04-21
UAL198 United Airlines 3 2026-04-24
UAL892 United Airlines 2 2026-05-30
UAL839 United Airlines 2 2026-04-18
UAL772 - 2 2026-04-13

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-06-02 UAL1757 PIT → DEN Jun 2, 22:25 UTCJun 3, 03:15 UTC4h 50m
2026-06-01 UAL223D CPT → IAD Jun 1, 20:05 UTCJun 2, 11:05 UTC15h 0m
2026-06-01 UAL1122 EWR → CPT Jun 1, 00:56 UTCJun 1, 14:46 UTC13h 50m
2026-06-01 UAL1122 EWR → CPT Jun 1, 00:55 UTCJun 1, 01:15 UTC20m
2026-05-30 UAL2480 BOS → SFO May 30, 22:50 UTCMay 31, 01:11 UTC2h 21m
2026-05-30 UAL892 ICN → SFO May 30, 08:25 UTCMay 30, 18:15 UTC9h 50m
2026-05-29 UAL893 SFO → ICN May 29, 18:20 UTCMay 30, 06:20 UTC12h 0m
2026-05-29 UAL61 BRU → EWR May 29, 01:09 UTCMay 29, 14:43 UTC13h 34m
2026-05-29 UAL61 BRU → EWR May 29, 01:10 UTCMay 29, 03:00 UTC1h 50m
2026-05-28 UAL60 SFO → MEL May 28, 07:04 UTCMay 28, 22:18 UTC15h 14m
2026-05-28 UAL60 SFO → MEL May 28, 07:25 UTCMay 28, 07:50 UTC25m
2026-05-27 UAL28 SIN → SFO May 27, 15:00 UTCMay 28, 04:35 UTC13h 35m
2026-05-27 UAL28 SIN → SFO May 27, 13:37 UTCMay 28, 04:29 UTC14h 52m
2026-05-26 UAL29 SFO → SIN May 26, 19:05 UTCMay 27, 09:35 UTC14h 30m
2026-05-25 UAL892 ICN → SFO May 25, 08:45 UTCMay 25, 18:45 UTC10h 0m
2026-05-24 UAL893 SFO → ICN May 24, 18:30 UTCMay 25, 06:26 UTC11h 56m
2026-05-24 UAL893 SFO → ICN May 24, 18:25 UTCMay 25, 06:40 UTC12h 15m
2026-05-24 UAL806 ICN → SFO May 24, 02:56 UTCMay 24, 12:49 UTC9h 53m
2026-05-24 UAL806 ICN → SFO May 24, 02:45 UTCMay 24, 12:50 UTC10h 5m
2026-05-23 UAL805 SFO → ICN May 23, 07:40 UTCMay 23, 19:20 UTC11h 40m
2026-05-22 UAL1757 PIT → DEN May 22, 22:40 UTCMay 23, 03:50 UTC5h 9m
2026-05-22 UAL1849 MCO → EWR May 22, 15:25 UTCMay 22, 19:50 UTC4h 25m
2026-05-18 UAL3968 SIN → SFO May 18, 18:30 UTCMay 19, 06:30 UTC12h 0m
2026-05-18 UAL3968 SIN → SFO May 18, 15:31 UTCMay 19, 06:23 UTC14h 52m
2026-05-14 UAL29 SFO → SIN May 14, 18:45 UTCMay 15, 09:25 UTC14h 40m
2026-05-14 UAL29 SFO → SIN May 14, 18:30 UTCMay 15, 10:52 UTC16h 22m
2026-05-14 UAL61 BRU → EWR May 14, 01:15 UTCMay 14, 14:50 UTC13h 35m
2026-05-13 UAL60 SFO → MEL May 13, 07:00 UTCMay 13, 22:20 UTC15h 20m
2026-05-12 UAL28 SIN → SFO May 12, 15:40 UTCMay 13, 04:45 UTC13h 5m
2026-05-03 UAL29 SFO → SIN May 3, 18:15 UTCMay 4, 10:35 UTC16h 20m
2026-05-03 UAL29 SFO → SIN May 3, 18:14 UTCMay 4, 08:55 UTC14h 40m
2026-05-03 UAL114 PPT → SFO May 3, 07:35 UTCMay 3, 15:10 UTC7h 35m
2026-05-03 UAL114 PPT → SFO May 3, 07:36 UTCMay 3, 15:05 UTC7h 29m
2026-05-02 UAL115 SFO → PPT May 2, 20:40 UTCMay 3, 05:20 UTC8h 39m
2026-05-02 UAL806 ICN → SFO May 2, 02:45 UTCMay 2, 12:45 UTC10h 0m
2026-05-01 UAL805 SFO → ICN May 1, 18:55 UTCMay 1, 19:20 UTC25m
2026-05-01 UAL805 SFO → ICN May 1, 07:30 UTCMay 1, 17:50 UTC10h 20m
2026-04-30 UAL1723 SBA → SFO Apr 30, 19:35 UTCMay 1, 00:55 UTC5h 20m
2026-04-30 UAL1723 SBA → SFO Apr 30, 19:42 UTCMay 1, 00:49 UTC5h 7m
2026-04-29 UAL1855 ORD → BOS Apr 29, 20:25 UTCApr 30, 00:45 UTC4h 19m
2026-04-29 UAL1855 ORD → BOS Apr 29, 20:31 UTCApr 30, 00:49 UTC4h 18m
2026-04-27 UAL821 SFO → MEX Apr 27, 15:00 UTCApr 28, 02:50 UTC11h 50m
2026-04-27 UAL821 SFO → MEX Apr 27, 14:10 UTCApr 27, 14:25 UTC15m
2026-04-27 UAL821 SFO → MEX Apr 27, 09:50 UTCApr 27, 10:15 UTC25m
2026-04-27 UAL820 MEX → SFO Apr 27, 00:05 UTCApr 27, 02:45 UTC2h 40m
2026-04-26 UAL820 MEX → SFO Apr 26, 21:15 UTCApr 26, 21:40 UTC25m
2026-04-26 UAL820 MEX → SFO Apr 26, 06:35 UTCApr 26, 20:45 UTC14h 10m
2026-04-25 UAL199 PVG → LAX Apr 25, 13:25 UTCApr 25, 14:35 UTC1h 10m
2026-04-25 UAL199 PVG → LAX Apr 25, 12:31 UTCApr 25, 23:33 UTC11h 2m
2026-04-24 UAL198 LAX → PVG Apr 24, 20:05 UTCApr 25, 08:00 UTC11h 55m

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 N25982 page for operator, model, and routing details .

Mode-S A27C78 frequently asked

What is Mode-S code A27C78?
A27C78 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N25982.
Where is Mode-S A27C78 registered?
Mode-S code A27C78 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 A27C78 broadcasting right now?
Yes. Mode-S A27C78 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A27C78, octal 50476170, decimal 10,648,696.
What flights does A27C78 operate?
Mode-S A27C78 has broadcast 20 distinct callsigns, including UAL29, UAL187, UAL1122, UAL199, UAL1321.