sensors Mode-S transponder

A71EFA

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N558UW · AIRBUS A-321 · operated by UMB BANK NA TRUSTEE

Hex
A71EFA
Octal
51617372
Decimal
10,952,442
Country
US
Tail
N558UW
Type
A321
Broadcasting now · callsign AAL1736 · 34,000 ft
Flights observed
257
Distinct callsigns
20
Country
US
Last broadcast
44m ago

Current position

A71EFA is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A71EFA 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

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 AAL1736 DFW → MSN May 29, 23:25 UTCMay 30, 00:30 UTC1h 5m
2026-05-29 AAL1486 GUA → DFW May 29, 20:25 UTCMay 29, 21:10 UTC45m
2026-05-29 AAL3073 DFW → CVG May 29, 16:05 UTCMay 29, 19:05 UTC3h 0m
2026-05-29 AAL3073 DFW → CVG May 29, 16:01 UTCMay 29, 19:00 UTC2h 59m
2026-05-29 AAL1194 ORD → BOS May 29, 13:20 UTCMay 29, 14:10 UTC50m
2026-05-29 AAL1238 EWR → DFW May 29, 05:00 UTCMay 29, 05:55 UTC55m
2026-05-29 AAL1238 EWR → DFW May 29, 04:58 UTCMay 29, 05:48 UTC50m
2026-05-28 AAL1984 SJC → CLT May 28, 22:10 UTCMay 29, 02:45 UTC4h 35m
2026-05-28 AAL1984 SJC → CLT May 28, 22:05 UTCMay 29, 02:35 UTC4h 30m
2026-05-28 AAL2641 CLT → LGA May 28, 11:20 UTCMay 28, 20:00 UTC8h 40m
2026-05-27 AAL1803 DCA → MIA May 27, 20:15 UTCMay 28, 00:25 UTC4h 10m
2026-05-27 AAL3079 PHL → MSY May 27, 15:30 UTCMay 27, 18:35 UTC3h 5m
2026-05-27 AAL3079 PHL → MSY May 27, 15:29 UTCMay 27, 18:38 UTC3h 9m
2026-05-27 AAL2843 CLT → ORD May 27, 12:00 UTCMay 27, 13:40 UTC1h 40m
2026-05-27 AAL2843 CLT → ORD May 27, 11:57 UTCMay 27, 13:33 UTC1h 36m
2026-05-27 AAL3035 TPA → MIA May 27, 05:35 UTCMay 27, 09:40 UTC4h 5m
2026-05-27 AAL3035 TPA → MIA May 27, 05:33 UTCMay 27, 09:41 UTC4h 8m
2026-05-27 AAL2364 LAX → ORD May 27, 00:34 UTCMay 27, 04:09 UTC3h 35m
2026-05-26 AAL338 LGA → MIA May 26, 19:34 UTCMay 26, 22:25 UTC2h 50m
2026-05-26 AAL2015 TYS → CLT May 26, 11:44 UTCMay 26, 15:49 UTC4h 5m
2026-05-26 AAL2015 TYS → CLT May 26, 11:42 UTCMay 26, 15:51 UTC4h 9m
2026-05-26 AAL3200 CLT → MCO May 26, 02:15 UTCMay 26, 03:19 UTC1h 5m
2026-05-25 AAL2525 ORD → MCO May 25, 18:15 UTCMay 25, 22:44 UTC4h 30m
2026-05-25 AAL2525 ORD → MCO May 25, 11:25 UTCMay 25, 16:20 UTC4h 55m
2026-05-24 AAL2465 SNA → DFW May 24, 20:40 UTCMay 24, 23:46 UTC3h 6m
2026-05-24 AAL3102 BOS → DFW May 24, 16:25 UTCMay 24, 18:55 UTC2h 30m
2026-05-24 AAL2172 MIA → DCA May 24, 12:20 UTCMay 24, 14:30 UTC2h 10m
2026-05-24 AAL2172 MIA → DCA May 24, 12:20 UTCMay 24, 14:31 UTC2h 11m
2026-05-24 AAL1879 CLT → MCO May 24, 03:20 UTCMay 24, 04:30 UTC1h 10m
2026-05-24 AAL1879 CLT → MCO May 24, 03:18 UTCMay 24, 04:28 UTC1h 10m
2026-05-23 AAL2038 JFK → CLT May 23, 22:10 UTCMay 24, 02:00 UTC3h 50m
2026-05-23 AAL2038 JFK → CLT May 23, 17:00 UTCMay 23, 20:55 UTC3h 55m
2026-05-23 AAL575 DFW → LGA May 23, 12:40 UTCMay 23, 15:25 UTC2h 45m
2026-05-23 AAL3314 SMF → DFW May 23, 07:15 UTCMay 23, 10:15 UTC3h 0m
2026-05-23 AAL3314 SMF → DFW May 23, 02:40 UTCMay 23, 06:00 UTC3h 20m
2026-05-22 AAL2376 CLT → SFO May 22, 22:50 UTCMay 23, 01:10 UTC2h 20m
2026-05-22 AAL2376 CLT → SFO May 22, 18:55 UTCMay 22, 21:20 UTC2h 25m
2026-05-22 AAL2305 JFK → SFO May 22, 13:55 UTCMay 22, 16:50 UTC2h 55m
2026-05-22 AAL446 DFW → SFO May 22, 05:10 UTCMay 22, 08:15 UTC3h 5m
2026-05-22 AAL2594 PHL → SAN May 22, 01:25 UTCMay 22, 03:30 UTC2h 5m
2026-05-21 AAL2594 PHL → SAN May 21, 21:45 UTCMay 22, 00:10 UTC2h 25m
2026-05-21 AAL1820 DFW → ONT May 21, 16:45 UTCMay 21, 20:10 UTC3h 25m
2026-05-21 AAL1820 DFW → ONT May 21, 12:20 UTCMay 21, 15:00 UTC2h 40m
2026-05-21 AAL1430 DFW → SFO May 21, 07:50 UTCMay 21, 10:50 UTC3h 0m
2026-05-20 AAL2411 SFO → PHX May 20, 22:25 UTCMay 21, 03:25 UTC5h 0m
2026-05-20 AAL2411 SFO → PHX May 20, 22:20 UTCMay 21, 03:22 UTC5h 2m
2026-05-20 AAL1522 JAX → CLT May 20, 19:25 UTCMay 20, 20:50 UTC1h 25m
2026-05-20 AAL2870 PHL → STL May 20, 14:35 UTCMay 20, 17:15 UTC2h 40m
2026-05-20 AAL2314 BWI → DFW May 20, 12:05 UTCMay 20, 13:05 UTC1h 0m
2026-05-20 AAL2314 BWI → DFW May 20, 12:01 UTCMay 20, 13:05 UTC1h 4m

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 N558UW page for operator, model, and routing details .

Mode-S A71EFA frequently asked

What is Mode-S code A71EFA?
A71EFA is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N558UW.
Where is Mode-S A71EFA registered?
Mode-S code A71EFA 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 A71EFA broadcasting right now?
Yes. Mode-S A71EFA is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A71EFA, octal 51617372, decimal 10,952,442.
What flights does A71EFA operate?
Mode-S A71EFA has broadcast 20 distinct callsigns, including AAL413, AAL2676, AAL2635, AAL1635, AAL2945.