Apparatus

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sensors Mode-S transponder

A53EEF

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N437UP · BOEING 757-200 · operated by UNITED PARCEL SERVICE CO

Hex
A53EEF
Octal
51237357
Decimal
10,829,551
Country
US
Tail
N437UP
Type
B752
No current signal · last broadcast 4h ago
Flights observed
225
Distinct callsigns
20
Country
US
Last broadcast
4h ago

Last known position

Most recent position reported by Mode-S A53EEF.

Country allocation

The ICAO 24-bit address A53EEF 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
UPS913 - 7 2026-07-10
UPS1314 - 7 2026-06-23
UPS988 United Parcel Service 6 2026-06-10
UPS1315 - 6 2026-06-24
UPS5922 - 5 2026-07-09
UPS5806 United Parcel Service 5 2026-06-10
UPS495 - 5 2026-06-26
UPS1244 - 5 2026-07-07
UPS805 United Parcel Service 4 2026-06-11
UPS673 United Parcel Service 4 2026-05-13
UPS672 - 4 2026-07-02
UPS5847 United Parcel Service 4 2026-05-12
UPS5674 United Parcel Service 4 2026-05-12
UPS496 - 4 2026-06-25
UPS1284 United Parcel Service 4 2026-05-05
UPS9821 United Parcel Service 3 2026-05-12
UPS9778 United Parcel Service 3 2026-06-11
UPS938 United Parcel Service 3 2026-05-29
UPS937 United Parcel Service 3 2026-05-30
UPS780 - 3 2026-06-26

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 UPS1358 - Jul 14, 09:05 UTCJul 14, 09:45 UTC40m
2026-07-14 UPS1358 SDF → HSV Jul 14, 09:09 UTCJul 14, 09:41 UTC32m
2026-07-11 UPS9307 - Jul 11, 13:25 UTCJul 11, 15:30 UTC2h 5m
2026-07-11 UPS1348 - Jul 11, 10:20 UTCJul 11, 12:15 UTC1h 55m
2026-07-11 UPS651 - Jul 11, 03:10 UTCJul 11, 04:40 UTC1h 30m
2026-07-10 UPS652 - Jul 10, 09:30 UTCJul 10, 10:35 UTC1h 5m
2026-07-10 UPS652 SDF → SGF Jul 10, 09:20 UTCJul 10, 10:37 UTC1h 17m
2026-07-10 UPS913 - Jul 10, 02:20 UTCJul 10, 06:00 UTC3h 40m
2026-07-10 UPS913 SNA → SDF Jul 10, 02:17 UTCJul 10, 05:46 UTC3h 29m
2026-07-09 UPS5922 - Jul 9, 19:25 UTCJul 9, 23:20 UTC3h 55m
2026-07-09 UPS2989 - Jul 9, 13:15 UTCJul 9, 16:50 UTC3h 35m
2026-07-09 UPS2989 BFI → SDF Jul 9, 13:11 UTCJul 9, 16:53 UTC3h 42m
2026-07-09 UPS990 DEN → BFI Jul 9, 09:38 UTCJul 9, 12:05 UTC2h 27m
2026-07-09 UPS990 - Jul 9, 05:30 UTCJul 9, 07:50 UTC2h 20m
2026-07-09 UPS1123 - Jul 9, 00:50 UTCJul 9, 02:25 UTC1h 35m
2026-07-08 UPS1124 - Jul 8, 08:55 UTCJul 8, 10:25 UTC1h 30m
2026-07-08 UPS1124 SDF → ALB Jul 8, 08:49 UTCJul 8, 10:27 UTC1h 38m
2026-07-08 UPS1269 ROA → SDF Jul 8, 03:00 UTCJul 8, 03:50 UTC50m
2026-07-08 UPS1269 ROA → SDF Jul 8, 02:55 UTCJul 8, 03:47 UTC52m
2026-07-08 UPS9844 - Jul 8, 01:05 UTCJul 8, 01:55 UTC50m
2026-07-08 UPS9844 CAE → ROA Jul 8, 01:04 UTCJul 8, 01:45 UTC41m
2026-07-07 UPS1244 - Jul 7, 08:00 UTCJul 7, 08:30 UTC30m
2026-07-07 UPS1244 GSO → CAE Jul 7, 07:58 UTCJul 7, 08:42 UTC44m
2026-07-07 UPS1244 - Jul 7, 06:05 UTCJul 7, 06:55 UTC50m
2026-07-07 UPS837 - Jul 7, 01:00 UTCJul 7, 04:15 UTC3h 15m
2026-07-07 UPS837 BOI → SDF Jul 7, 00:52 UTCJul 7, 04:05 UTC3h 13m
2026-07-06 UPS5838 - Jul 6, 06:40 UTCJul 6, 10:05 UTC3h 25m
2026-07-03 UPS5441 MIA → SDF Jul 3, 10:33 UTCJul 3, 12:28 UTC1h 55m
2026-07-03 UPS304 - Jul 3, 06:25 UTCJul 3, 07:45 UTC1h 20m
2026-07-03 UPS304 SDF → MIA Jul 3, 06:34 UTCJul 3, 08:20 UTC1h 46m
2026-07-03 UPS671 - Jul 3, 02:05 UTCJul 3, 03:25 UTC1h 20m
2026-07-02 UPS672 - Jul 2, 09:15 UTCJul 2, 10:40 UTC1h 25m
2026-07-02 UPS672 SDF → ICT Jul 2, 09:08 UTCJul 2, 10:36 UTC1h 28m
2026-07-02 UPS913 - Jul 2, 02:40 UTCJul 2, 06:00 UTC3h 20m
2026-07-02 UPS913 SNA → SDF Jul 2, 02:39 UTCJul 2, 06:02 UTC3h 23m
2026-07-01 UPS5922 - Jul 1, 19:35 UTCJul 1, 23:30 UTC3h 55m
2026-07-01 UPS5922 SDF → SNA Jul 1, 19:41 UTCJul 1, 23:31 UTC3h 50m
2026-06-30 UPS5837 - Jun 30, 13:10 UTCJun 30, 15:45 UTC2h 35m
2026-06-30 UPS5837 BOI → SDF Jun 30, 13:08 UTCJun 30, 16:24 UTC3h 16m
2026-06-30 UPS838 SDF → BOI Jun 30, 07:45 UTCJun 30, 11:10 UTC3h 25m
2026-06-30 UPS838 SDF → BOI Jun 30, 07:44 UTCJun 30, 11:15 UTC3h 31m
2026-06-30 UPS943 SJC → SDF Jun 30, 02:10 UTCJun 30, 05:55 UTC3h 45m
2026-06-30 UPS943 SJC → SDF Jun 30, 02:07 UTCJun 30, 05:55 UTC3h 48m
2026-06-29 UPS9820 MHR → LAX Jun 29, 23:19 UTCJun 29, 23:44 UTC25m
2026-06-28 UPS5942 SDF → OAK Jun 28, 21:14 UTCJun 29, 01:39 UTC4h 25m
2026-06-28 UPS5942 SDF → OAK Jun 28, 21:05 UTCJun 29, 01:33 UTC4h 28m
2026-06-27 UPS781 LRD → SDF Jun 27, 00:39 UTCJun 27, 02:55 UTC2h 15m
2026-06-26 UPS780 - Jun 26, 11:20 UTCJun 26, 11:49 UTC30m
2026-06-26 UPS780 - Jun 26, 09:20 UTCJun 26, 10:05 UTC45m
2026-06-26 UPS780 - Jun 26, 06:50 UTCJun 26, 08:34 UTC1h 45m

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 N437UP page for operator, model, and routing details .

Mode-S A53EEF frequently asked

What is Mode-S code A53EEF?
A53EEF is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N437UP.
Where is Mode-S A53EEF registered?
Mode-S code A53EEF 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 A53EEF broadcasting right now?
No active broadcast right now. Last signal was 4h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A53EEF, octal 51237357, decimal 10,829,551.
What flights does A53EEF operate?
Mode-S A53EEF has broadcast 20 distinct callsigns, including UPS913, UPS1314, UPS988, UPS1315, UPS5922.