sensors Mode-S transponder

A24C73

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N24702 · BOEING 737-700 · operated by UNITED AIRLINES INC

Hex
A24C73
Octal
50446163
Decimal
10,636,403
Country
US
Tail
N24702
Type
B737
No current signal · last broadcast 1d ago
Flights observed
10
Distinct callsigns
7
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A24C73.

Country allocation

The ICAO 24-bit address A24C73 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 7 distinct

Callsign Airline Flights Last seen
UAL358 - 2 2026-04-13
UAL2634 - 2 2026-04-13
UAL2471 United Airlines 2 2026-04-13
UAL2382 United Airlines 1 2026-04-13
UAL1869 - 1 2026-04-13
UAL1789 United Airlines 1 2026-04-13
UAL1288 United Airlines 1 2026-04-12

Recent flights last 10

DateFlightRouteTakeoffLandingDuration
2026-04-13 UAL1869 - Apr 13, 22:00 UTCApr 13, 23:45 UTC1h 45m
2026-04-13 UAL358 - Apr 13, 19:50 UTCApr 13, 20:05 UTC15m
2026-04-13 UAL358 DFW → IAD Apr 13, 17:35 UTCApr 13, 20:05 UTC2h 30m
2026-04-13 UAL2471 SAN → EWR Apr 13, 15:50 UTCApr 13, 16:15 UTC25m
2026-04-13 UAL2471 SAN → EWR Apr 13, 13:05 UTCApr 13, 16:15 UTC3h 10m
2026-04-13 UAL1789 DEN → SJC Apr 13, 10:15 UTCApr 13, 10:55 UTC40m
2026-04-13 UAL2382 IAH → PHL Apr 13, 02:46 UTCApr 13, 03:29 UTC43m
2026-04-13 UAL2634 - Apr 13, 00:20 UTCApr 13, 01:25 UTC1h 5m
2026-04-12 UAL2634 - Apr 12, 23:55 UTCApr 13, 01:25 UTC1h 30m
2026-04-12 UAL1288 OGG → SFO Apr 12, 17:15 UTCApr 12, 17:40 UTC25m

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 N24702 page for operator, model, and routing details .

Mode-S A24C73 frequently asked

What is Mode-S code A24C73?
A24C73 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N24702.
Where is Mode-S A24C73 registered?
Mode-S code A24C73 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 A24C73 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A24C73, octal 50446163, decimal 10,636,403.
What flights does A24C73 operate?
Mode-S A24C73 has broadcast 7 distinct callsigns, including UAL358, UAL2634, UAL2471, UAL2382, UAL1869.