sensors Mode-S transponder

A126ED

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N17317 · BOEING 737 MAX 8 · operated by UNITED AIRLINES INC

Hex
A126ED
Octal
50223355
Decimal
10,561,261
Country
US
Tail
N17317
Type
B38M
No current signal · last broadcast 12h ago
Flights observed
10
Distinct callsigns
5
Country
US
Last broadcast
12h ago

Last known position

Most recent position reported by Mode-S A126ED.

Country allocation

The ICAO 24-bit address A126ED 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 5 distinct

Callsign Airline Flights Last seen
UAL508 United Airlines 4 2026-04-13
UAL438 United Airlines 3 2026-04-14
UAL437 - 1 2026-04-13
UAL268 United Airlines 1 2026-04-13
UAL1499 - 1 2026-04-12

Recent flights last 10

DateFlightRouteTakeoffLandingDuration
2026-04-14 UAL438 BOI → SFO Apr 14, 09:10 UTCApr 14, 11:05 UTC1h 55m
2026-04-14 UAL438 BOI → SFO Apr 14, 08:45 UTCApr 14, 09:05 UTC20m
2026-04-14 UAL438 BOI → SFO Apr 14, 05:20 UTCApr 14, 07:05 UTC1h 45m
2026-04-13 UAL437 - Apr 13, 21:41 UTCApr 14, 03:28 UTC5h 47m
2026-04-13 UAL508 BOG → IAH Apr 13, 16:15 UTCApr 13, 19:05 UTC2h 50m
2026-04-13 UAL508 BOG → IAH Apr 13, 15:50 UTCApr 13, 19:05 UTC3h 15m
2026-04-13 UAL508 BOG → IAH Apr 13, 13:58 UTCApr 13, 18:49 UTC4h 51m
2026-04-13 UAL508 BOG → IAH Apr 13, 13:58 UTCApr 13, 19:14 UTC5h 16m
2026-04-13 UAL268 EWR → BOG Apr 13, 02:00 UTCApr 13, 02:25 UTC25m
2026-04-12 UAL1499 - Apr 12, 17:15 UTCApr 12, 19:15 UTC2h 0m

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 N17317 page for operator, model, and routing details .

Mode-S A126ED frequently asked

What is Mode-S code A126ED?
A126ED is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N17317.
Where is Mode-S A126ED registered?
Mode-S code A126ED 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 A126ED broadcasting right now?
No active broadcast right now. Last signal was 12h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A126ED, octal 50223355, decimal 10,561,261.
What flights does A126ED operate?
Mode-S A126ED has broadcast 5 distinct callsigns, including UAL508, UAL438, UAL437, UAL268, UAL1499.