Apparatus

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sensors Mode-S transponder

A00B91

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N10156 · EMBRAER ERJ-145XR · operated by UNITED AIRLINES INC

Hex
A00B91
Octal
50005621
Decimal
10,488,721
Country
US
Tail
N10156
Type
E45X
No current signal · last broadcast 43m ago
Flights observed
529
Distinct callsigns
20
Country
US
Last broadcast
43m ago

Last known position

Most recent position reported by Mode-S A00B91.

Country allocation

The ICAO 24-bit address A00B91 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
UCA4362 - 8 2026-07-07
UCA4332 CommutAir 7 2026-05-23
UCA4307 - 7 2026-06-19
UCA4275 - 7 2026-06-24
UCA4237 - 7 2026-06-26
UCA4228 - 7 2026-06-29
UCA4923 CommutAir 6 2026-05-30
UCA4860 CommutAir 6 2026-04-29
UCA4364 CommutAir 6 2026-05-26
UCA4302 - 6 2026-07-10
UCA4277 - 6 2026-06-25
UCA4276 - 6 2026-06-25
UCA4258 - 6 2026-06-29
UCA4252 - 6 2026-07-08
UCA4230 - 6 2026-07-03
UCA4947 - 5 2026-07-01
UCA4361 - 5 2026-06-24
UCA4298 - 5 2026-06-30
UCA4260 - 5 2026-07-01
UCA4989 - 4 2026-07-13

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-15 UCA4351 - Jul 15, 00:25 UTCJul 15, 02:00 UTC1h 35m
2026-07-14 UCA4946 - Jul 14, 21:35 UTCJul 14, 23:15 UTC1h 39m
2026-07-13 UCA4338 - Jul 13, 22:50 UTCJul 14, 00:05 UTC1h 15m
2026-07-13 UCA4338 XNA → IAH Jul 13, 22:49 UTCJul 14, 00:04 UTC1h 15m
2026-07-13 UCA4297 - Jul 13, 20:55 UTCJul 13, 22:00 UTC1h 5m
2026-07-13 UCA4297 IAH → XNA Jul 13, 21:05 UTCJul 13, 22:14 UTC1h 9m
2026-07-13 UCA4989 - Jul 13, 14:15 UTCJul 13, 15:25 UTC1h 10m
2026-07-12 UCA4295 - Jul 12, 23:30 UTCJul 13, 01:30 UTC2h 0m
2026-07-11 UCA4238 BTV → IAD Jul 11, 01:30 UTCJul 11, 02:40 UTC1h 10m
2026-07-10 UCA4302 IAD → BTV Jul 10, 22:35 UTCJul 10, 23:45 UTC1h 10m
2026-07-10 UCA4302 IAD → BTV Jul 10, 22:13 UTCJul 10, 23:44 UTC1h 31m
2026-07-10 UCA4925 - Jul 10, 19:35 UTCJul 10, 20:55 UTC1h 20m
2026-07-10 UCA4930 IAD → MHT Jul 10, 17:30 UTCJul 10, 18:40 UTC1h 10m
2026-07-10 UCA4227 - Jul 10, 15:05 UTCJul 10, 15:50 UTC45m
2026-07-10 UCA4965 - Jul 10, 13:00 UTCJul 10, 13:30 UTC30m
2026-07-10 UCA4922 ROA → IAD Jul 10, 10:25 UTCJul 10, 11:05 UTC40m
2026-07-10 UCA4897 IAD → ROA Jul 10, 05:13 UTCJul 10, 05:36 UTC23m
2026-07-10 UCA4897 IAD → ROA Jul 10, 05:05 UTCJul 10, 05:45 UTC40m
2026-07-10 UCA4810 - Jul 10, 03:25 UTCJul 10, 04:00 UTC35m
2026-07-10 UCA4308 IAD → ORF Jul 10, 01:35 UTCJul 10, 02:20 UTC45m
2026-07-09 UCA4268 - Jul 9, 23:30 UTCJul 10, 00:00 UTC30m
2026-07-09 UCA4268 MDT → IAD Jul 9, 22:57 UTCJul 9, 23:59 UTC1h 2m
2026-07-09 UCA4372 - Jul 9, 17:05 UTCJul 9, 17:35 UTC30m
2026-07-09 UCA4958 - Jul 9, 14:45 UTCJul 9, 15:50 UTC1h 5m
2026-07-09 UCA4961 - Jul 9, 12:30 UTCJul 9, 13:30 UTC1h 0m
2026-07-08 UCA4229 - Jul 8, 19:00 UTCJul 8, 19:55 UTC55m
2026-07-08 UCA4288 - Jul 8, 16:55 UTCJul 8, 17:50 UTC55m
2026-07-08 UCA4281 - Jul 8, 14:50 UTCJul 8, 15:10 UTC20m
2026-07-08 UCA4333 - Jul 8, 13:05 UTCJul 8, 13:20 UTC15m
2026-07-08 UCA4359 - Jul 8, 10:15 UTCJul 8, 10:45 UTC30m
2026-07-08 UCA4252 IAD → SCE Jul 8, 02:53 UTCJul 8, 03:29 UTC36m
2026-07-08 UCA4313 - Jul 8, 00:05 UTCJul 8, 01:10 UTC1h 5m
2026-07-07 UCA4963 - Jul 7, 22:05 UTCJul 7, 23:05 UTC1h 0m
2026-07-07 UCA4362 - Jul 7, 19:10 UTCJul 7, 20:05 UTC55m
2026-07-07 UCA4362 SYR → IAD Jul 7, 19:08 UTCJul 7, 20:04 UTC56m
2026-07-07 UCA4360 IAD → SYR Jul 7, 17:05 UTCJul 7, 17:52 UTC47m
2026-07-07 UCA4360 - Jul 7, 17:10 UTCJul 7, 17:55 UTC45m
2026-07-07 UCA4974 - Jul 7, 14:45 UTCJul 7, 15:15 UTC30m
2026-07-07 UCA4974 MDT → IAD Jul 7, 14:42 UTCJul 7, 15:13 UTC31m
2026-07-07 UCA4986 - Jul 7, 13:20 UTCJul 7, 13:45 UTC25m
2026-07-07 UCA4853 - Jul 7, 05:15 UTCJul 7, 05:35 UTC20m
2026-07-07 UCA4853 - Jul 7, 02:00 UTCJul 7, 04:05 UTC2h 5m
2026-07-06 UCA4977 - Jul 6, 23:35 UTCJul 7, 00:40 UTC1h 5m
2026-07-06 UCA4977 IAD → SYR Jul 6, 22:15 UTCJul 7, 00:36 UTC2h 21m
2026-07-06 UCA4327 - Jul 6, 20:25 UTCJul 6, 21:05 UTC40m
2026-07-06 UCA3262 - Jul 6, 17:45 UTCJul 6, 19:30 UTC1h 45m
2026-07-06 UCA3262 MHT → GSO Jul 6, 17:32 UTCJul 6, 19:13 UTC1h 41m
2026-07-06 UCA3272 - Jul 6, 04:40 UTCJul 6, 05:15 UTC35m
2026-07-05 UCA4302 IAD → BTV Jul 5, 22:10 UTCJul 5, 23:25 UTC1h 15m
2026-07-05 UCA4325 - Jul 5, 14:20 UTCJul 5, 15:35 UTC1h 15m

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 N10156 page for operator, model, and routing details .

Mode-S A00B91 frequently asked

What is Mode-S code A00B91?
A00B91 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N10156.
Where is Mode-S A00B91 registered?
Mode-S code A00B91 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 A00B91 broadcasting right now?
No active broadcast right now. Last signal was 43m ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A00B91, octal 50005621, decimal 10,488,721.
What flights does A00B91 operate?
Mode-S A00B91 has broadcast 20 distinct callsigns, including UCA4362, UCA4332, UCA4307, UCA4275, UCA4237.