Apparatus

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sensors Mode-S transponder

AA9EEF

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N78361 · EMBRAER ERJ-170-200 (long wing) · operated by UNITED AIRLINES INC

Hex
AA9EEF
Octal
52517357
Decimal
11,181,807
Country
US
Tail
N78361
Type
E75L
No current signal · last broadcast Jul 26, 21:45 UTC
Flights observed
674
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:45 UTC

Last known position

Most recent position reported by Mode-S AA9EEF.

Country allocation

The ICAO 24-bit address AA9EEF 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
SKW5968 - 9 2026-07-19
SKW5491 SkyWest Airlines 9 2026-07-20
SKW5450 SkyWest Airlines 8 2026-07-21
SKW5702 SkyWest Airlines 6 2026-07-18
SKW5417 - 6 2026-07-09
SKW5384 SkyWest Airlines 6 2026-05-29
SKW5350 SkyWest Airlines 6 2026-07-22
SKW5978 SkyWest Airlines 5 2026-05-21
SKW5782 SkyWest Airlines 5 2026-05-04
SKW5765 SkyWest Airlines 5 2026-05-26
SKW5457 SkyWest Airlines 5 2026-06-13
SKW5422 - 5 2026-07-09
SKW5419 SkyWest Airlines 5 2026-07-19
SKW5290 SkyWest Airlines 5 2026-07-22
SKW4787 - 5 2026-06-27
SKW4764 - 5 2026-06-23
SKW4730 - 5 2026-06-23
SKW4643 SkyWest Airlines 5 2026-05-29
SKW463C - 5 2026-07-11
SKW5923 - 4 2026-06-19

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SKW5262 ORD → MKE Jul 26, 21:25 UTCJul 26, 21:45 UTC20m
2026-07-26 SKW5509 PSP → SFO Jul 26, 19:30 UTCJul 26, 20:05 UTC35m
2026-07-26 SKW4788 GEG → SFO Jul 26, 14:45 UTCJul 26, 17:35 UTC2h 50m
2026-07-26 SKW4788 GEG → SFO Jul 26, 14:33 UTCJul 26, 17:22 UTC2h 49m
2026-07-25 SKW5416 EUG → SFO Jul 25, 21:15 UTCJul 26, 00:05 UTC2h 50m
2026-07-25 SKW4788 GEG → SFO Jul 25, 14:40 UTCJul 25, 17:10 UTC2h 30m
2026-07-24 SKW5416 EUG → SFO Jul 24, 21:15 UTCJul 25, 00:00 UTC2h 45m
2026-07-24 SKW5447 MFR → SFO Jul 24, 18:20 UTCJul 24, 18:50 UTC30m
2026-07-24 SKW318J ORD → MSN Jul 24, 17:10 UTCJul 24, 17:40 UTC30m
2026-07-24 SKW4673 - Jul 24, 14:00 UTCJul 24, 15:50 UTC1h 50m
2026-07-24 SKW5194 ORD → BJX Jul 24, 11:15 UTCJul 24, 12:50 UTC1h 35m
2026-07-23 SKW6000 HPN → ORD Jul 23, 22:10 UTCJul 23, 23:40 UTC1h 30m
2026-07-23 SKW725M ORD → TYS Jul 23, 19:50 UTCJul 23, 20:50 UTC1h 0m
2026-07-23 SKW5266 OKC → IAH Jul 23, 14:40 UTCJul 23, 17:45 UTC3h 5m
2026-07-23 SKW5719 PWM → ORD Jul 23, 01:15 UTCJul 23, 04:35 UTC3h 20m
2026-07-23 SKW5719 PWM → ORD Jul 23, 01:22 UTCJul 23, 04:33 UTC3h 11m
2026-07-22 SKW5350 RDM → SFO Jul 22, 23:40 UTCJul 22, 23:50 UTC10m
2026-07-22 SKW5350 RDM → SFO Jul 22, 22:05 UTCJul 22, 23:50 UTC1h 45m
2026-07-22 SKW5350 RDM → SFO Jul 22, 22:07 UTCJul 22, 23:24 UTC1h 17m
2026-07-22 SKW5337 ORD → SAV Jul 22, 19:25 UTCJul 22, 20:45 UTC1h 20m
2026-07-22 SKW5386 - Jul 22, 14:35 UTCJul 22, 17:25 UTC2h 50m
2026-07-22 SKW5290 ORD → HSV Jul 22, 03:10 UTCJul 22, 05:00 UTC1h 50m
2026-07-22 SKW5290 ORD → HSV Jul 22, 02:57 UTCJul 22, 06:36 UTC3h 39m
2026-07-21 SKW5350 RDM → SFO Jul 21, 22:55 UTCJul 22, 01:35 UTC2h 40m
2026-07-21 SKW5350 RDM → SFO Jul 21, 22:40 UTCJul 22, 01:17 UTC2h 37m
2026-07-21 SKW5337 ORD → SAV Jul 21, 20:05 UTCJul 21, 21:50 UTC1h 45m
2026-07-21 SKW5874 YUL → ORD Jul 21, 15:35 UTCJul 21, 17:55 UTC2h 20m
2026-07-21 SKW4654 TYS → ORD Jul 21, 12:45 UTCJul 21, 14:30 UTC1h 45m
2026-07-21 SKW5450 SMF → SFO Jul 21, 00:15 UTCJul 21, 01:55 UTC1h 40m
2026-07-21 SKW5450 SMF → SFO Jul 21, 00:17 UTCJul 21, 01:47 UTC1h 30m
2026-07-20 SKW5552 BUR → SFO Jul 20, 21:45 UTCJul 20, 23:05 UTC1h 20m
2026-07-20 SKW5570 MSP → ORD Jul 20, 18:25 UTCJul 20, 19:30 UTC1h 5m
2026-07-20 SKW5684 - Jul 20, 15:45 UTCJul 20, 16:45 UTC1h 0m
2026-07-20 SKW5491 SGF → ORD Jul 20, 12:25 UTCJul 20, 14:01 UTC1h 36m
2026-07-20 SKW5491 SGF → ORD Jul 20, 12:10 UTCJul 20, 14:10 UTC2h 0m
2026-07-20 SKW5645 JAC → SFO Jul 20, 02:05 UTCJul 20, 03:55 UTC1h 50m
2026-07-19 SKW5264 - Jul 19, 22:40 UTCJul 19, 23:55 UTC1h 15m
2026-07-19 SKW5867 - Jul 19, 20:25 UTCJul 19, 21:15 UTC50m
2026-07-19 SKW5419 SBA → SFO Jul 19, 17:55 UTCJul 19, 18:35 UTC40m
2026-07-19 SKW5419 SBA → SFO Jul 19, 17:49 UTCJul 19, 18:20 UTC31m
2026-07-19 SKW5968 ORD → IND Jul 19, 16:10 UTCJul 19, 16:40 UTC30m
2026-07-19 SKW5968 ORD → IND Jul 19, 16:08 UTCJul 19, 16:39 UTC31m
2026-07-19 SKW5491 SGF → ORD Jul 19, 12:35 UTCJul 19, 14:08 UTC1h 33m
2026-07-19 SKW5491 SGF → ORD Jul 19, 12:25 UTCJul 19, 13:45 UTC1h 20m
2026-07-19 SKW5645 JAC → SFO Jul 19, 03:30 UTCJul 19, 05:25 UTC1h 55m
2026-07-19 SKW5645 JAC → SFO Jul 19, 03:35 UTCJul 19, 05:14 UTC1h 39m
2026-07-18 SKW5702 ASE → ORD Jul 18, 23:45 UTCJul 19, 02:00 UTC2h 15m
2026-07-18 SKW4703 - Jul 18, 16:00 UTCJul 18, 17:55 UTC1h 55m
2026-07-18 SKW5615 - Jul 18, 14:20 UTCJul 18, 14:55 UTC35m
2026-07-18 SKW5615 GRR → ORD Jul 18, 14:23 UTCJul 18, 14:46 UTC23m

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 N78361 page for operator, model, and routing details .

Mode-S AA9EEF frequently asked

What is Mode-S code AA9EEF?
AA9EEF is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N78361.
Where is Mode-S AA9EEF registered?
Mode-S code AA9EEF 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 AA9EEF 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 AA9EEF, octal 52517357, decimal 11,181,807.
What flights does AA9EEF operate?
Mode-S AA9EEF has broadcast 20 distinct callsigns, including SKW5968, SKW5491, SKW5450, SKW5702, SKW5417.