Apparatus

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sensors Mode-S transponder

AA4C87

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N76288 · BOEING 737-800 · operated by UNITED AIRLINES INC

Hex
AA4C87
Octal
52446207
Decimal
11,160,711
Country
US
Tail
N76288
Type
B738
No current signal · last broadcast Jul 26, 21:45 UTC
Flights observed
464
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:45 UTC

Last known position

Most recent position reported by Mode-S AA4C87.

Country allocation

The ICAO 24-bit address AA4C87 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
UAL1185 United Airlines 6 2026-05-08
UAL2110 - 5 2026-06-15
UAL1973 - 5 2026-07-17
UAL469 United Airlines 4 2026-06-09
UAL2645 United Airlines 4 2026-05-08
UAL1570 - 4 2026-07-08
UAL1534 - 4 2026-06-24
UAL1156 United Airlines 4 2026-07-26
UAL645 United Airlines 3 2026-05-26
UAL637 United Airlines 3 2026-05-10
UAL547 United Airlines 3 2026-05-08
UAL390 United Airlines 3 2026-07-18
UAL2480 - 3 2026-07-17
UAL2446 United Airlines 3 2026-07-23
UAL2325 - 3 2026-07-05
UAL2236 United Airlines 3 2026-06-03
UAL2188 United Airlines 3 2026-06-01
UAL2167 - 3 2026-06-24
UAL2151 United Airlines 3 2026-07-23
UAL2145 United Airlines 3 2026-04-17

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL1156 IAD → EWR Jul 26, 20:50 UTCJul 26, 21:45 UTC55m
2026-07-26 UAL2267 EWR → RDU Jul 26, 17:20 UTCJul 26, 19:00 UTC1h 40m
2026-07-26 UAL1057 DEN → SFO Jul 26, 13:35 UTCJul 26, 15:00 UTC1h 25m
2026-07-26 UAL1057 DEN → SFO Jul 26, 13:25 UTCJul 26, 15:15 UTC1h 50m
2026-07-26 UAL1655 BNA → EWR Jul 26, 01:05 UTCJul 26, 02:45 UTC1h 40m
2026-07-25 UAL329 SRQ → EWR Jul 25, 21:20 UTCJul 25, 23:05 UTC1h 45m
2026-07-25 UAL2418 IAD → BDL Jul 25, 16:40 UTCJul 25, 19:50 UTC3h 10m
2026-07-25 UAL2418 IAD → BDL Jul 25, 16:22 UTCJul 25, 19:44 UTC3h 22m
2026-07-25 UAL2754 BOG → EWR Jul 25, 12:20 UTCJul 25, 14:20 UTC2h 0m
2026-07-25 UAL1371 SNA → ORD Jul 25, 02:05 UTCJul 25, 04:15 UTC2h 10m
2026-07-24 UAL1781 EWR → CHS Jul 24, 22:25 UTCJul 25, 00:05 UTC1h 40m
2026-07-24 UAL1311 EWR → CLT Jul 24, 19:45 UTCJul 24, 21:05 UTC1h 20m
2026-07-24 UAL1537 RSW → EWR Jul 24, 15:55 UTCJul 24, 18:15 UTC2h 20m
2026-07-24 UAL1537 RSW → EWR Jul 24, 14:35 UTCJul 24, 15:50 UTC1h 15m
2026-07-23 UAL1776 LAX → SFO Jul 23, 23:25 UTCJul 24, 00:50 UTC1h 25m
2026-07-23 UAL2005 DFW → SFO Jul 23, 19:20 UTCJul 23, 21:30 UTC2h 10m
2026-07-23 UAL2672 DEN → MSN Jul 23, 16:30 UTCJul 23, 18:05 UTC1h 35m
2026-07-23 UAL2151 PDX → DEN Jul 23, 13:15 UTCJul 23, 13:40 UTC25m
2026-07-23 UAL2151 PDX → DEN Jul 23, 13:27 UTCJul 23, 13:31 UTC4m
2026-07-23 UAL630 BUF → ORD Jul 23, 04:00 UTCJul 23, 04:25 UTC25m
2026-07-23 UAL2446 FLL → EWR Jul 23, 02:15 UTCJul 23, 02:30 UTC15m
2026-07-23 UAL2446 FLL → EWR Jul 23, 00:06 UTCJul 23, 02:00 UTC1h 54m
2026-07-23 UAL2446 FLL → EWR Jul 23, 00:20 UTCJul 23, 02:30 UTC2h 10m
2026-07-22 UAL1617 IAH → BOS Jul 22, 21:15 UTCJul 22, 22:45 UTC1h 30m
2026-07-22 UAL493 CLE → IAD Jul 22, 18:35 UTCJul 22, 19:35 UTC1h 0m
2026-07-22 UAL493 CLE → IAD Jul 22, 18:46 UTCJul 22, 19:16 UTC30m
2026-07-22 UAL2849 EWR → DOM Jul 22, 16:05 UTCJul 22, 16:55 UTC50m
2026-07-22 UAL1332 DCA → ORD Jul 22, 11:55 UTCJul 22, 14:15 UTC2h 20m
2026-07-22 UAL395 EWR → SFO Jul 22, 03:50 UTCJul 22, 05:25 UTC1h 35m
2026-07-22 UAL2108 EWR → CHS Jul 22, 00:55 UTCJul 22, 02:25 UTC1h 30m
2026-07-21 UAL2156 IAD → LAS Jul 21, 18:40 UTCJul 21, 23:15 UTC4h 35m
2026-07-21 UAL525 AUS → IAD Jul 21, 12:50 UTCJul 21, 15:50 UTC3h 0m
2026-07-20 UAL2337 SFO → BOS Jul 20, 22:15 UTCJul 21, 01:00 UTC2h 44m
2026-07-20 UAL2366 SFO → LAS Jul 20, 17:40 UTCJul 20, 20:20 UTC2h 40m
2026-07-20 UAL1935 ORD → LGA Jul 20, 10:45 UTCJul 20, 13:15 UTC2h 30m
2026-07-19 UAL2131 BFI → IAD Jul 19, 20:15 UTCJul 20, 00:25 UTC4h 10m
2026-07-19 UAL8201 YYZ → MSP Jul 19, 13:20 UTCJul 19, 18:35 UTC5h 15m
2026-07-18 UAL391 BOS → EWR Jul 18, 20:45 UTCJul 19, 00:25 UTC3h 40m
2026-07-18 UAL391 BOS → EWR Jul 18, 19:55 UTCJul 18, 20:05 UTC10m
2026-07-18 UAL390 SNA → SFO Jul 18, 17:45 UTCJul 18, 18:05 UTC20m
2026-07-18 UAL390 SNA → SFO Jul 18, 13:33 UTCJul 18, 17:56 UTC4h 23m
2026-07-18 UAL390 SNA → SFO Jul 18, 13:45 UTCJul 18, 14:30 UTC45m
2026-07-18 UAL2129 - Jul 18, 05:15 UTCJul 18, 09:40 UTC4h 25m
2026-07-17 UAL1147 - Jul 17, 22:49 UTCJul 18, 00:00 UTC1h 10m
2026-07-17 UAL2480 YVR → SFO Jul 17, 19:00 UTCJul 17, 21:10 UTC2h 10m
2026-07-17 UAL1973 - Jul 17, 05:04 UTCJul 17, 06:45 UTC1h 40m
2026-07-17 UAL1973 SFO → YVR Jul 17, 04:53 UTCJul 17, 06:37 UTC1h 44m
2026-07-17 UAL2216 YVR → SFO Jul 17, 01:06 UTCJul 17, 03:11 UTC2h 5m
2026-07-17 UAL2216 YVR → SFO Jul 17, 01:09 UTCJul 17, 03:20 UTC2h 10m
2026-07-16 UAL1151 SFO → YVR Jul 16, 21:35 UTCJul 16, 23:15 UTC1h 40m

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 N76288 page for operator, model, and routing details .

Mode-S AA4C87 frequently asked

What is Mode-S code AA4C87?
AA4C87 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N76288.
Where is Mode-S AA4C87 registered?
Mode-S code AA4C87 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 AA4C87 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 21:45 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AA4C87, octal 52446207, decimal 11,160,711.
What flights does AA4C87 operate?
Mode-S AA4C87 has broadcast 20 distinct callsigns, including UAL1185, UAL2110, UAL1973, UAL469, UAL2645.