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
No current signal · last broadcast 3h ago
Flights observed
171
Distinct callsigns
20
Country
US
Last broadcast
3h ago

Last known position

Most recent position reported by Mode-S A27C78.

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
UAL187 - 10 2026-06-28
UAL806 - 8 2026-07-07
UAL60 - 8 2026-07-03
UAL29 - 8 2026-06-19
UAL805 - 7 2026-07-06
UAL28 - 7 2026-06-20
UAL61 - 6 2026-07-04
UAL114 - 6 2026-07-09
UAL1122 - 6 2026-06-29
UAL893 - 5 2026-07-09
UAL2222 - 5 2026-06-29
UAL199 United Airlines 5 2026-06-12
UAL198 United Airlines 5 2026-07-17
UAL188 United Airlines 5 2026-06-27
UAL115 - 5 2026-07-08
UAL892 - 4 2026-07-10
UAL713 - 4 2026-06-22
UAL32 - 4 2026-07-13
UAL1321 United Airlines 4 2026-04-17
UAL863 - 3 2026-07-12

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-17 UAL198 LAX → PVG Jul 17, 20:40 UTCJul 18, 07:50 UTC11h 11m
2026-07-17 UAL33 NRT → LAX Jul 17, 08:30 UTCJul 17, 18:40 UTC10h 10m
2026-07-17 UAL33 NRT → LAX Jul 17, 08:05 UTCJul 17, 18:34 UTC10h 29m
2026-07-16 UAL7 - Jul 16, 15:55 UTCJul 17, 04:25 UTC12h 30m
2026-07-16 UAL63 - Jul 16, 01:10 UTCJul 16, 10:35 UTC9h 25m
2026-07-15 UAL62 - Jul 15, 00:20 UTCJul 15, 09:30 UTC9h 10m
2026-07-14 UAL6 - Jul 14, 08:40 UTCJul 14, 20:25 UTC11h 45m
2026-07-14 UAL6 NRT → IAH Jul 14, 08:42 UTCJul 14, 20:18 UTC11h 36m
2026-07-13 UAL32 - Jul 13, 18:10 UTCJul 14, 04:45 UTC10h 35m
2026-07-13 UAL842 - Jul 13, 00:01 UTCJul 13, 12:50 UTC12h 50m
2026-07-12 UAL863 - Jul 12, 07:31 UTCJul 12, 08:01 UTC30m
2026-07-12 UAL863 SFO → SYD Jul 12, 06:49 UTCJul 12, 21:20 UTC14h 31m
2026-07-11 UAL969 - Jul 11, 13:30 UTCJul 12, 00:25 UTC10h 55m
2026-07-10 UAL968 - Jul 10, 22:25 UTCJul 11, 08:01 UTC9h 35m
2026-07-10 UAL892 ICN → SFO Jul 10, 08:24 UTCJul 10, 18:21 UTC9h 57m
2026-07-10 UAL892 - Jul 10, 08:15 UTCJul 10, 09:50 UTC1h 35m
2026-07-09 UAL893 - Jul 9, 18:30 UTCJul 10, 06:05 UTC11h 35m
2026-07-09 UAL893 SFO → ICN Jul 9, 18:10 UTCJul 10, 05:55 UTC11h 45m
2026-07-09 UAL114 - Jul 9, 07:10 UTCJul 9, 14:40 UTC7h 30m
2026-07-08 UAL115 SFO → PPT Jul 8, 21:05 UTCJul 9, 04:45 UTC7h 40m
2026-07-08 UAL114 - Jul 8, 07:10 UTCJul 8, 14:45 UTC7h 35m
2026-07-07 UAL115 SFO → PPT Jul 7, 20:52 UTCJul 8, 04:50 UTC7h 58m
2026-07-07 UAL115 - Jul 7, 20:55 UTCJul 8, 05:00 UTC8h 5m
2026-07-07 UAL806 - Jul 7, 02:45 UTCJul 7, 13:10 UTC10h 25m
2026-07-06 UAL805 - Jul 6, 07:45 UTCJul 6, 19:25 UTC11h 40m
2026-07-05 UAL939 - Jul 5, 15:40 UTCJul 6, 02:00 UTC10h 20m
2026-07-05 UAL930 SFO → LHR Jul 5, 03:45 UTCJul 5, 13:25 UTC9h 40m
2026-07-04 UAL61 - Jul 4, 02:35 UTCJul 4, 16:10 UTC13h 35m
2026-07-03 UAL60 SFO → MEL Jul 3, 07:06 UTCJul 3, 22:11 UTC15h 5m
2026-07-03 UAL60 - Jul 3, 07:00 UTCJul 3, 22:00 UTC15h 0m
2026-07-02 UAL1227 - Jul 2, 18:45 UTCJul 3, 00:00 UTC5h 15m
2026-07-02 UAL123 - Jul 2, 06:55 UTCJul 2, 14:00 UTC7h 5m
2026-07-01 UAL122 EWR → LHR Jul 1, 13:55 UTCJul 1, 20:00 UTC6h 5m
2026-06-29 UAL2222 CPT → EWR Jun 29, 18:12 UTCJun 30, 08:32 UTC14h 20m
2026-06-29 UAL2222 CPT → EWR Jun 29, 17:49 UTCJun 30, 08:55 UTC15h 5m
2026-06-29 UAL1122 - Jun 29, 01:55 UTCJun 29, 15:14 UTC13h 20m
2026-06-28 UAL187 - Jun 28, 11:45 UTCJun 28, 11:50 UTC5m
2026-06-27 UAL187 JNB → EWR Jun 27, 20:19 UTCJun 28, 11:25 UTC15h 6m
2026-06-27 UAL187 JNB → EWR Jun 27, 20:19 UTCJun 28, 11:48 UTC15h 29m
2026-06-27 UAL188 EWR → JNB Jun 27, 02:14 UTCJun 27, 16:14 UTC14h 0m
2026-06-25 UAL83 DEL → EWR Jun 25, 18:34 UTCJun 25, 19:09 UTC35m
2026-06-25 UAL83 DEL → EWR Jun 25, 18:32 UTCJun 26, 10:03 UTC15h 31m
2026-06-25 UAL82 EWR → DEL Jun 25, 01:44 UTCJun 25, 15:34 UTC13h 50m
2026-06-23 UAL187 - Jun 23, 20:04 UTCJun 24, 10:39 UTC14h 35m
2026-06-23 UAL188 EWR → JNB Jun 23, 03:20 UTCJun 23, 17:30 UTC14h 10m
2026-06-22 UAL713 - Jun 22, 18:04 UTCJun 22, 22:40 UTC4h 35m
2026-06-22 UAL713 SFO → EWR Jun 22, 17:53 UTCJun 22, 22:33 UTC4h 40m
2026-06-22 UAL61 - Jun 22, 01:15 UTCJun 22, 14:45 UTC13h 30m
2026-06-21 UAL60 SFO → MEL Jun 21, 07:25 UTCJun 21, 22:29 UTC15h 5m
2026-06-20 UAL28 - Jun 20, 15:54 UTCJun 20, 16:39 UTC45m

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?
No active broadcast right now. Last signal was 3h ago.
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 UAL187, UAL806, UAL60, UAL29, UAL805.