Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A1B5E7

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N20904 · BOEING 787-8 Dreamliner · operated by UNITED AIRLINES INC

Hex
A1B5E7
Octal
50332747
Decimal
10,597,863
Country
US
Tail
N20904
Type
B788
Broadcasting now · callsign UAL909 · 41,000 ft
Flights observed
212
Distinct callsigns
20
Country
US
Last broadcast
3h ago

Current position

A1B5E7 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A1B5E7 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
UAL108 - 20 2026-07-12
UAL109 - 19 2026-07-12
UAL953 - 14 2026-07-12
UAL952 - 14 2026-07-13
UAL981 - 13 2026-07-03
UAL997 - 9 2026-06-26
UAL996 - 9 2026-06-25
UAL770 - 8 2026-07-09
UAL769 - 8 2026-07-09
UAL992 United Airlines 7 2026-07-07
UAL991 - 7 2026-07-07
UAL982 - 7 2026-07-06
UAL909 - 7 2026-07-14
UAL980 - 6 2026-07-03
UAL908 - 6 2026-07-11
UAL345 - 6 2026-06-29
UAL983 - 5 2026-07-06
UAL543 United Airlines 5 2026-05-20
UAL1777 United Airlines 5 2026-05-21
UAL3900 United Airlines 4 2026-05-16

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 UAL909 - Jul 14, 00:00 UTCJul 14, 02:30 UTC2h 30m
2026-07-13 UAL952 MUC → ORD Jul 13, 09:45 UTCJul 13, 18:25 UTC8h 40m
2026-07-13 UAL952 MUC → ORD Jul 13, 09:47 UTCJul 13, 18:06 UTC8h 19m
2026-07-12 UAL108 IAD → MUC Jul 12, 22:30 UTCJul 13, 06:35 UTC8h 5m
2026-07-12 UAL109 MUC → IAD Jul 12, 10:20 UTCJul 12, 18:35 UTC8h 15m
2026-07-12 UAL953 - Jul 12, 01:15 UTCJul 12, 01:30 UTC15m
2026-07-11 UAL953 ORD → MUC Jul 11, 23:42 UTCJul 12, 07:17 UTC7h 35m
2026-07-11 UAL953 - Jul 11, 23:10 UTCJul 12, 01:10 UTC2h 0m
2026-07-11 UAL908 - Jul 11, 10:20 UTCJul 11, 18:20 UTC8h 0m
2026-07-11 UAL908 AMS → ORD Jul 11, 10:20 UTCJul 11, 18:01 UTC7h 41m
2026-07-11 UAL909 AMS → AMS Jul 11, 07:05 UTCJul 11, 07:10 UTC5m
2026-07-11 UAL909 - Jul 11, 00:00 UTCJul 11, 07:10 UTC7h 10m
2026-07-11 UAL909 ORD → AMS Jul 11, 00:12 UTCJul 11, 06:50 UTC6h 38m
2026-07-09 UAL770 BCN → ORD Jul 9, 13:41 UTCJul 9, 22:23 UTC8h 42m
2026-07-09 UAL770 BCN → ORD Jul 9, 13:35 UTCJul 9, 22:35 UTC9h 0m
2026-07-09 UAL769 ORD → BCN Jul 9, 03:00 UTCJul 9, 10:55 UTC7h 55m
2026-07-08 UAL952 - Jul 8, 09:50 UTCJul 8, 18:45 UTC8h 55m
2026-07-07 UAL108 EWR → EDI Jul 7, 22:43 UTCJul 8, 06:15 UTC7h 32m
2026-07-07 UAL108 EWR → EDI Jul 7, 22:50 UTCJul 8, 06:20 UTC7h 30m
2026-07-07 UAL991 BCN → IAD Jul 7, 12:45 UTCJul 7, 20:35 UTC7h 50m
2026-07-07 UAL992 IAD → BCN Jul 7, 00:56 UTCJul 7, 08:39 UTC7h 43m
2026-07-07 UAL992 IAD → BCN Jul 7, 01:25 UTCJul 7, 07:45 UTC6h 20m
2026-07-06 UAL983 ATH → IAD Jul 6, 11:40 UTCJul 6, 21:55 UTC10h 15m
2026-07-06 UAL982 IAD → ATH Jul 6, 00:00 UTCJul 6, 09:00 UTC9h 0m
2026-07-05 UAL109 EDI → EWR Jul 5, 10:20 UTCJul 5, 11:45 UTC1h 25m
2026-07-05 UAL109 EDI → EWR Jul 5, 10:19 UTCJul 5, 18:59 UTC8h 40m
2026-07-04 UAL953 - Jul 4, 23:30 UTCJul 5, 07:15 UTC7h 45m
2026-07-04 UAL908 AMS → ORD Jul 4, 10:20 UTCJul 4, 18:10 UTC7h 50m
2026-07-04 UAL908 AMS → ORD Jul 4, 10:15 UTCJul 4, 18:30 UTC8h 15m
2026-07-04 UAL909 ORD → AMS Jul 4, 00:15 UTCJul 4, 07:10 UTC6h 55m
2026-07-03 UAL981 - Jul 3, 19:30 UTCJul 3, 19:55 UTC25m
2026-07-03 UAL981 DUB → ORD Jul 3, 11:23 UTCJul 3, 19:13 UTC7h 50m
2026-07-03 UAL981 DUB → ORD Jul 3, 11:25 UTCJul 3, 19:55 UTC8h 30m
2026-07-03 UAL980 ORD → DUB Jul 3, 02:40 UTCJul 3, 09:05 UTC6h 25m
2026-07-02 UAL952 - Jul 2, 10:25 UTCJul 2, 19:30 UTC9h 5m
2026-07-02 UAL953 - Jul 2, 00:00 UTCJul 2, 08:25 UTC8h 25m
2026-07-01 UAL952 - Jul 1, 10:15 UTCJul 1, 19:00 UTC8h 45m
2026-06-30 UAL108 EWR → EDI Jun 30, 22:00 UTCJul 1, 05:45 UTC7h 45m
2026-06-30 UAL108 EWR → EDI Jun 30, 21:53 UTCJul 1, 05:42 UTC7h 49m
2026-06-30 UAL344 HNL → IAD Jun 30, 02:20 UTCJun 30, 10:40 UTC8h 20m
2026-06-30 UAL344 HNL → IAD Jun 30, 02:09 UTCJun 30, 10:38 UTC8h 29m
2026-06-29 UAL345 - Jun 29, 13:04 UTCJun 29, 22:24 UTC9h 20m
2026-06-29 UAL3919 - Jun 29, 00:54 UTCJun 29, 09:14 UTC8h 20m
2026-06-29 UAL3919 HNL → IAD Jun 29, 00:51 UTCJun 29, 09:13 UTC8h 22m
2026-06-27 UAL345 IAD → HNL Jun 27, 21:55 UTCJun 27, 22:20 UTC25m
2026-06-27 UAL345 IAD → HNL Jun 27, 12:50 UTCJun 27, 17:59 UTC5h 10m
2026-06-27 UAL344 HNL → IAD Jun 27, 05:55 UTCJun 27, 09:44 UTC3h 50m
2026-06-27 UAL344 HNL → IAD Jun 27, 01:49 UTCJun 27, 01:59 UTC10m
2026-06-26 UAL345 IAD → HNL Jun 26, 22:40 UTCJun 26, 23:04 UTC25m
2026-06-26 UAL345 IAD → HNL Jun 26, 13:50 UTCJun 26, 23:03 UTC9h 13m

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 N20904 page for operator, model, and routing details .

Mode-S A1B5E7 frequently asked

What is Mode-S code A1B5E7?
A1B5E7 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N20904.
Where is Mode-S A1B5E7 registered?
Mode-S code A1B5E7 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 A1B5E7 broadcasting right now?
Yes. Mode-S A1B5E7 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A1B5E7, octal 50332747, decimal 10,597,863.
What flights does A1B5E7 operate?
Mode-S A1B5E7 has broadcast 20 distinct callsigns, including UAL108, UAL109, UAL953, UAL952, UAL981.