Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A126C4

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N17301 · BOEING 737 MAX 8 · operated by UMB BANK NA TRUSTEE

Hex
A126C4
Octal
50223304
Decimal
10,561,220
Country
US
Tail
N17301
Type
B38M
No current signal · last broadcast Jul 26, 18:40 UTC
Flights observed
480
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 18:40 UTC

Last known position

Most recent position reported by Mode-S A126C4.

Country allocation

The ICAO 24-bit address A126C4 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
UAL1903 United Airlines 7 2026-05-16
UAL2392 - 6 2026-07-01
UAL2199 United Airlines 6 2026-04-30
UAL1976 United Airlines 6 2026-04-16
UAL1407 United Airlines 6 2026-04-29
UAL1299 United Airlines 6 2026-06-12
UAL205 United Airlines 5 2026-07-23
UAL1985 - 5 2026-07-01
UAL1977 United Airlines 5 2026-04-16
UAL1965 - 5 2026-07-05
UAL1847 United Airlines 5 2026-05-22
UAL1753 United Airlines 5 2026-07-02
UAL1295 United Airlines 5 2026-07-19
UAL765 - 4 2026-07-16
UAL437 United Airlines 4 2026-04-15
UAL2092 United Airlines 4 2026-05-14
UAL1898 United Airlines 4 2026-05-09
UAL1751 United Airlines 4 2026-05-08
UAL1459 United Airlines 4 2026-04-30
UAL1433 United Airlines 4 2026-05-09

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL718 MEX → SFO Jul 26, 14:05 UTCJul 26, 18:30 UTC4h 25m
2026-07-26 UAL718 MEX → SFO Jul 26, 13:54 UTCJul 26, 18:34 UTC4h 40m
2026-07-25 UAL1065 EWR → MEX Jul 25, 19:55 UTCJul 26, 00:20 UTC4h 25m
2026-07-25 UAL1065 EWR → MEX Jul 25, 19:51 UTCJul 26, 00:18 UTC4h 27m
2026-07-25 UAL217 SFO → PDX Jul 25, 15:05 UTCJul 25, 17:00 UTC1h 55m
2026-07-25 UAL216 ATL → SFO Jul 25, 08:10 UTCJul 25, 08:25 UTC15m
2026-07-25 UAL216 ATL → SFO Jul 25, 03:25 UTCJul 25, 04:40 UTC1h 15m
2026-07-24 UAL348 OGG → ORD Jul 24, 18:33 UTCJul 24, 22:01 UTC3h 28m
2026-07-24 UAL297 SFO → SAN Jul 24, 12:00 UTCJul 24, 21:00 UTC9h 0m
2026-07-24 UAL559 EWR → CLE Jul 24, 04:35 UTCJul 24, 09:40 UTC5h 5m
2026-07-23 UAL205 AUS → EWR Jul 23, 20:05 UTCJul 24, 00:25 UTC4h 20m
2026-07-23 UAL2421 MCO → ORD Jul 23, 16:15 UTCJul 23, 18:20 UTC2h 5m
2026-07-23 UAL2421 MCO → ORD Jul 23, 16:07 UTCJul 23, 18:12 UTC2h 5m
2026-07-23 UAL1353 IAD → EWR Jul 23, 12:40 UTCJul 23, 14:35 UTC1h 55m
2026-07-23 UAL206 BOG → IAH Jul 23, 05:40 UTCJul 23, 10:35 UTC4h 55m
2026-07-22 UAL268 EWR → BOG Jul 22, 21:30 UTCJul 23, 02:30 UTC5h 0m
2026-07-22 UAL269 BOG → EWR Jul 22, 12:50 UTCJul 22, 18:10 UTC5h 20m
2026-07-21 UAL643 KOA → SFO Jul 21, 22:15 UTCJul 22, 01:10 UTC2h 55m
2026-07-21 UAL2780 IAD → EWR Jul 21, 17:50 UTCJul 21, 20:35 UTC2h 45m
2026-07-21 UAL2748 - Jul 21, 12:10 UTCJul 21, 16:05 UTC3h 55m
2026-07-21 UAL684 LAS → LAX Jul 21, 02:20 UTCJul 21, 04:30 UTC2h 10m
2026-07-20 UAL387 YVR → LAX Jul 20, 22:05 UTCJul 21, 00:35 UTC2h 30m
2026-07-20 UAL2318 DEN → LAX Jul 20, 18:10 UTCJul 20, 20:25 UTC2h 15m
2026-07-19 UAL1296 EWR → TPA Jul 19, 23:15 UTCJul 20, 04:15 UTC5h 0m
2026-07-19 UAL1295 LAX → LIH Jul 19, 16:00 UTCJul 19, 21:15 UTC5h 15m
2026-07-19 UAL1612 - Jul 19, 08:10 UTCJul 19, 13:00 UTC4h 50m
2026-07-19 UAL1104 SJC → DEN Jul 19, 00:30 UTCJul 19, 05:55 UTC5h 25m
2026-07-18 UAL2184 - Jul 18, 21:55 UTCJul 18, 22:35 UTC40m
2026-07-18 UAL2184 LAS → LAX Jul 18, 21:56 UTCJul 18, 22:38 UTC42m
2026-07-18 UAL8124 - Jul 18, 17:40 UTCJul 18, 20:10 UTC2h 30m
2026-07-18 UAL8124 IAH → LAS Jul 18, 17:42 UTCJul 18, 20:09 UTC2h 27m
2026-07-18 UAL1901 - Jul 18, 13:20 UTCJul 18, 14:50 UTC1h 30m
2026-07-18 UAL1901 - Jul 18, 12:25 UTCJul 18, 12:35 UTC10m
2026-07-18 UAL1137 LAX → GUA Jul 18, 06:20 UTCJul 18, 10:35 UTC4h 15m
2026-07-18 UAL1137 LAX → GUA Jul 18, 06:11 UTCJul 18, 10:32 UTC4h 21m
2026-07-17 UAL1296 - Jul 17, 23:14 UTCJul 18, 04:10 UTC4h 56m
2026-07-17 UAL1295 LAX → LIH Jul 17, 16:00 UTCJul 17, 21:15 UTC5h 15m
2026-07-17 UAL1295 LAX → LIH Jul 17, 16:07 UTCJul 17, 21:23 UTC5h 16m
2026-07-17 UAL627 - Jul 17, 05:20 UTCJul 17, 06:00 UTC40m
2026-07-16 UAL765 - Jul 16, 18:15 UTCJul 16, 18:44 UTC30m
2026-07-16 UAL765 LAX → OGG Jul 16, 18:16 UTCJul 16, 23:31 UTC5h 15m
2026-07-16 UAL1692 - Jul 16, 13:15 UTCJul 16, 15:30 UTC2h 15m
2026-07-16 UAL2820 ORD → SEA Jul 16, 02:15 UTCJul 16, 06:00 UTC3h 45m
2026-07-15 UAL1009 SBA → ORD Jul 15, 19:45 UTCJul 15, 23:45 UTC4h 0m
2026-07-15 UAL1008 - Jul 15, 13:55 UTCJul 15, 17:35 UTC3h 40m
2026-07-15 UAL2766 - Jul 15, 07:55 UTCJul 15, 08:00 UTC5m
2026-07-15 UAL2766 SMF → ORD Jul 15, 04:20 UTCJul 15, 08:00 UTC3h 40m
2026-07-15 UAL2766 SMF → ORD Jul 15, 03:56 UTCJul 15, 07:38 UTC3h 42m
2026-07-15 UAL3901 - Jul 15, 01:50 UTCJul 15, 02:50 UTC1h 0m
2026-07-14 UAL2487 - Jul 14, 17:15 UTCJul 14, 18:10 UTC55m

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 N17301 page for operator, model, and routing details .

Mode-S A126C4 frequently asked

What is Mode-S code A126C4?
A126C4 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N17301.
Where is Mode-S A126C4 registered?
Mode-S code A126C4 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 A126C4 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 18:40 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A126C4, octal 50223304, decimal 10,561,220.
What flights does A126C4 operate?
Mode-S A126C4 has broadcast 20 distinct callsigns, including UAL1903, UAL2392, UAL2199, UAL1976, UAL1407.