sensors Mode-S transponder

A837A7

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N62896 · BOEING 737-900 · operated by UNITED AIRLINES INC

Hex
A837A7
Octal
52033647
Decimal
11,024,295
Country
US
Tail
N62896
Type
B739
Broadcasting now · callsign UAL1275 · 34,000 ft
Flights observed
6
Distinct callsigns
6
Country
US
Last broadcast
23h ago

Current position

A837A7 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A837A7 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 6 distinct

Callsign Airline Flights Last seen
UAL720 - 1 2026-04-13
UAL550 - 1 2026-04-13
UAL486 - 1 2026-04-13
UAL431 - 1 2026-04-12
UAL1521 United Airlines 1 2026-04-13
UAL1421 - 1 2026-04-12

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-13 UAL486 - Apr 13, 20:55 UTCApr 13, 23:40 UTC2h 45m
2026-04-13 UAL1521 IAD → MSY Apr 13, 17:26 UTCApr 13, 19:44 UTC2h 18m
2026-04-13 UAL550 YYC → DEN Apr 13, 13:35 UTCApr 13, 15:35 UTC2h 0m
2026-04-13 UAL720 DEN → YYC Apr 13, 01:34 UTCApr 13, 03:43 UTC2h 9m
2026-04-12 UAL431 - Apr 12, 23:55 UTCApr 13, 00:00 UTC5m
2026-04-12 UAL1421 - Apr 12, 16:28 UTCApr 12, 19:10 UTC2h 42m

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 N62896 page for operator, model, and routing details .

Mode-S A837A7 frequently asked

What is Mode-S code A837A7?
A837A7 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N62896.
Where is Mode-S A837A7 registered?
Mode-S code A837A7 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 A837A7 broadcasting right now?
Yes. Mode-S A837A7 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A837A7, octal 52033647, decimal 11,024,295.
What flights does A837A7 operate?
Mode-S A837A7 has broadcast 6 distinct callsigns, including UAL720, UAL550, UAL486, UAL431, UAL1521.