Apparatus

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sensors Mode-S transponder

AA3AE9

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N75858 · BOEING 757-300 · operated by UNITED AIRLINES INC

Hex
AA3AE9
Octal
52435351
Decimal
11,156,201
Country
US
Tail
N75858
Type
B753
No current signal · last broadcast Jul 24, 22:30 UTC
Flights observed
394
Distinct callsigns
20
Country
US
Last broadcast
Jul 24, 22:30 UTC

Last known position

Most recent position reported by Mode-S AA3AE9.

Country allocation

The ICAO 24-bit address AA3AE9 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
UAL1722 United Airlines 20 2026-07-24
UAL1721 United Airlines 20 2026-07-23
UAL1176 - 15 2026-07-14
UAL638 - 14 2026-07-14
UAL373 - 14 2026-07-13
UAL1431 - 14 2026-07-05
UAL1509 - 12 2026-07-10
UAL1221 United Airlines 11 2026-06-20
UAL2348 - 10 2026-07-14
UAL1734 United Airlines 10 2026-05-14
UAL501 United Airlines 9 2026-07-21
UAL1495 United Airlines 9 2026-06-01
UAL2282 United Airlines 8 2026-07-21
UAL1022 United Airlines 8 2026-07-22
UAL246 United Airlines 7 2026-07-20
UAL1954 United Airlines 7 2026-07-20
UAL1654 United Airlines 7 2026-07-23
UAL1577 United Airlines 7 2026-07-19
UAL1967 - 6 2026-07-21
UAL1946 United Airlines 6 2026-05-09

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-24 UAL1722 OGG → SFO Jul 24, 21:30 UTCJul 24, 22:25 UTC55m
2026-07-24 UAL1722 OGG → SFO Jul 24, 17:55 UTCJul 24, 18:10 UTC15m
2026-07-23 UAL1721 SFO → KOA Jul 23, 23:30 UTCJul 23, 23:35 UTC5m
2026-07-23 UAL1721 SFO → KOA Jul 23, 18:17 UTCJul 23, 23:31 UTC5h 14m
2026-07-23 UAL1721 SFO → KOA Jul 23, 18:00 UTCJul 23, 19:05 UTC1h 5m
2026-07-23 UAL2391 ORD → EWR Jul 23, 14:10 UTCJul 23, 16:25 UTC2h 15m
2026-07-23 UAL1654 OMA → SFO Jul 23, 02:50 UTCJul 23, 05:05 UTC2h 15m
2026-07-22 UAL1829 EWR → SFO Jul 22, 20:15 UTCJul 22, 22:05 UTC1h 50m
2026-07-22 UAL1022 DEN → SAT Jul 22, 14:55 UTCJul 22, 18:05 UTC3h 10m
2026-07-21 UAL501 MCO → EWR Jul 21, 20:05 UTCJul 22, 00:10 UTC4h 5m
2026-07-21 UAL1865 SLC → EWR Jul 21, 15:00 UTCJul 21, 18:10 UTC3h 10m
2026-07-21 UAL1865 SLC → EWR Jul 21, 14:33 UTCJul 21, 18:05 UTC3h 32m
2026-07-21 UAL2282 SAN → IAD Jul 21, 08:15 UTCJul 21, 12:45 UTC4h 30m
2026-07-21 UAL1967 - Jul 21, 02:15 UTCJul 21, 06:00 UTC3h 45m
2026-07-20 UAL1954 RDM → SFO Jul 20, 17:45 UTCJul 20, 21:30 UTC3h 45m
2026-07-20 UAL246 ORD → LGA Jul 20, 11:45 UTCJul 20, 15:50 UTC4h 5m
2026-07-20 UAL1375 JAX → EWR Jul 20, 03:10 UTCJul 20, 06:30 UTC3h 20m
2026-07-19 UAL1577 RNO → SFO Jul 19, 20:15 UTCJul 20, 00:05 UTC3h 50m
2026-07-19 UAL1941 IAD → EWR Jul 19, 14:10 UTCJul 19, 18:05 UTC3h 55m
2026-07-19 UAL1636 LAX → SFO Jul 19, 06:30 UTCJul 19, 07:10 UTC40m
2026-07-19 UAL1636 LAX → SFO Jul 19, 02:30 UTCJul 19, 02:40 UTC10m
2026-07-18 UAL1224 - Jul 18, 19:05 UTCJul 19, 00:25 UTC5h 20m
2026-07-18 UAL1224 LAX → HNL Jul 18, 18:45 UTCJul 19, 00:14 UTC5h 29m
2026-07-18 UAL1967 - Jul 18, 02:09 UTCJul 18, 05:45 UTC3h 36m
2026-07-17 UAL1954 SFO → ORD Jul 17, 17:50 UTCJul 17, 22:00 UTC4h 10m
2026-07-17 UAL246 - Jul 17, 11:50 UTCJul 17, 15:35 UTC3h 45m
2026-07-17 UAL1375 JAX → EWR Jul 17, 02:15 UTCJul 17, 05:55 UTC3h 40m
2026-07-16 UAL2633 - Jul 16, 22:25 UTCJul 17, 00:55 UTC2h 30m
2026-07-16 UAL1604 SFO → DEN Jul 16, 18:15 UTCJul 16, 20:19 UTC2h 5m
2026-07-16 UAL1604 SFO → DEN Jul 16, 18:06 UTCJul 16, 20:15 UTC2h 9m
2026-07-16 UAL2391 - Jul 16, 14:15 UTCJul 16, 16:25 UTC2h 10m
2026-07-15 UAL1865 IAD → DEN Jul 15, 18:00 UTCJul 15, 20:45 UTC2h 45m
2026-07-14 UAL347 DEN → IAD Jul 14, 20:20 UTCJul 14, 23:25 UTC3h 4m
2026-07-14 UAL2348 SFO → DEN Jul 14, 16:00 UTCJul 14, 18:05 UTC2h 5m
2026-07-14 UAL1176 - Jul 14, 13:05 UTCJul 14, 14:00 UTC55m
2026-07-14 UAL1176 - Jul 14, 09:25 UTCJul 14, 09:40 UTC15m
2026-07-14 UAL638 SFO → HNL Jul 14, 02:50 UTCJul 14, 07:35 UTC4h 45m
2026-07-14 UAL638 SFO → HNL Jul 14, 02:54 UTCJul 14, 07:33 UTC4h 39m
2026-07-13 UAL373 - Jul 13, 23:20 UTCJul 14, 00:20 UTC1h 0m
2026-07-13 UAL373 - Jul 13, 19:35 UTCJul 13, 19:50 UTC15m
2026-07-13 UAL373 HNL → SFO Jul 13, 19:25 UTCJul 14, 00:16 UTC4h 51m
2026-07-13 UAL638 - Jul 13, 02:15 UTCJul 13, 02:45 UTC30m
2026-07-13 UAL638 SFO → HNL Jul 13, 02:24 UTCJul 13, 07:02 UTC4h 38m
2026-07-12 UAL2633 DEN → SFO Jul 12, 22:05 UTCJul 13, 00:15 UTC2h 10m
2026-07-12 UAL8104 SFO → DEN Jul 12, 18:21 UTCJul 12, 20:16 UTC1h 55m
2026-07-12 UAL8104 SFO → DEN Jul 12, 18:15 UTCJul 12, 20:15 UTC2h 0m
2026-07-12 UAL2391 DEN → SFO Jul 12, 13:58 UTCJul 12, 16:05 UTC2h 7m
2026-07-12 UAL2391 - Jul 12, 14:01 UTCJul 12, 16:10 UTC2h 10m
2026-07-11 UAL1654 - Jul 11, 23:50 UTCJul 12, 01:45 UTC1h 55m
2026-07-11 UAL1654 IAH → DEN Jul 11, 23:40 UTCJul 12, 01:42 UTC2h 2m

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 N75858 page for operator, model, and routing details .

Mode-S AA3AE9 frequently asked

What is Mode-S code AA3AE9?
AA3AE9 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N75858.
Where is Mode-S AA3AE9 registered?
Mode-S code AA3AE9 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 AA3AE9 broadcasting right now?
No active broadcast right now. Last signal was Jul 24, 22:30 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AA3AE9, octal 52435351, decimal 11,156,201.
What flights does AA3AE9 operate?
Mode-S AA3AE9 has broadcast 20 distinct callsigns, including UAL1722, UAL1721, UAL1176, UAL638, UAL373.