sensors Mode-S transponder

A2B691

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N274NN · EMBRAER ERJ-170-200 (long wing) · operated by AMERICAN AIRLINES INC

Hex
A2B691
Octal
50533221
Decimal
10,663,569
Country
US
Tail
N274NN
Type
E75L
Broadcasting now · callsign ENY4193 · 28,000 ft
Flights observed
15
Distinct callsigns
7
Country
US
Last broadcast
1d ago

Current position

A2B691 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A2B691 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
ENY3973 - 3 2026-04-13
ENY3874 - 3 2026-04-13
ENY3646 - 3 2026-04-13
ENY4114 - 2 2026-04-12
ENY3915 - 2 2026-04-13
ENY3541 - 1 2026-04-13
ENY3411 - 1 2026-04-13

Recent flights last 15

DateFlightRouteTakeoffLandingDuration
2026-04-13 ENY3915 - Apr 13, 21:45 UTCApr 13, 23:44 UTC1h 59m
2026-04-13 ENY3915 - Apr 13, 21:45 UTCApr 13, 23:30 UTC1h 45m
2026-04-13 ENY3646 - Apr 13, 19:50 UTCApr 13, 21:05 UTC1h 15m
2026-04-13 ENY3646 - Apr 13, 19:14 UTCApr 13, 20:54 UTC1h 40m
2026-04-13 ENY3646 - Apr 13, 19:21 UTCApr 13, 21:08 UTC1h 47m
2026-04-13 ENY3874 - Apr 13, 16:15 UTCApr 13, 17:30 UTC1h 15m
2026-04-13 ENY3874 - Apr 13, 15:50 UTCApr 13, 16:15 UTC25m
2026-04-13 ENY3874 - Apr 13, 13:26 UTCApr 13, 14:55 UTC1h 29m
2026-04-13 ENY3541 - Apr 13, 10:47 UTCApr 13, 11:18 UTC31m
2026-04-13 ENY3411 - Apr 13, 04:20 UTCApr 13, 04:40 UTC20m
2026-04-13 ENY3973 - Apr 13, 00:20 UTCApr 13, 00:55 UTC35m
2026-04-12 ENY3973 - Apr 12, 23:57 UTCApr 13, 01:01 UTC1h 4m
2026-04-12 ENY3973 - Apr 12, 23:58 UTCApr 13, 00:52 UTC54m
2026-04-12 ENY4114 - Apr 12, 19:25 UTCApr 12, 20:15 UTC50m
2026-04-12 ENY4114 - Apr 12, 17:30 UTCApr 12, 18:25 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 N274NN page for operator, model, and routing details .

Mode-S A2B691 frequently asked

What is Mode-S code A2B691?
A2B691 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N274NN.
Where is Mode-S A2B691 registered?
Mode-S code A2B691 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 A2B691 broadcasting right now?
Yes. Mode-S A2B691 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A2B691, octal 50533221, decimal 10,663,569.
What flights does A2B691 operate?
Mode-S A2B691 has broadcast 7 distinct callsigns, including ENY3973, ENY3874, ENY3646, ENY4114, ENY3915.