sensors Mode-S transponder

A339B1

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N307DU · AIRBUS A220-300 · operated by DELTA AIR LINES INC

Hex
A339B1
Octal
50634661
Decimal
10,697,137
Country
US
Tail
N307DU
Type
BCS3
Broadcasting now · callsign DAL2054 · 35,000 ft
Flights observed
7
Distinct callsigns
5
Country
US
Last broadcast
16h ago

Current position

A339B1 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A339B1 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
DAL2231 - 2 2026-04-13
DAL1116 - 2 2026-04-13
DAL2413 - 1 2026-04-13
DAL1614 Delta Air Lines 1 2026-04-14
DAL1423 Delta Air Lines 1 2026-04-12

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-14 DAL1614 LGA → MIA Apr 14, 05:15 UTCApr 14, 06:35 UTC1h 20m
2026-04-13 DAL1116 - Apr 13, 20:15 UTCApr 13, 21:35 UTC1h 20m
2026-04-13 DAL1116 SLC → LGB Apr 13, 17:25 UTCApr 13, 19:10 UTC1h 45m
2026-04-13 DAL2231 - Apr 13, 15:50 UTCApr 13, 16:15 UTC25m
2026-04-13 DAL2231 ORD → SLC Apr 13, 12:58 UTCApr 13, 16:08 UTC3h 10m
2026-04-13 DAL2413 SLC → ORD Apr 13, 00:45 UTCApr 13, 03:30 UTC2h 45m
2026-04-12 DAL1423 MSN → DTW Apr 12, 17:30 UTCApr 12, 18:55 UTC1h 25m

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 N307DU page for operator, model, and routing details .

Mode-S A339B1 frequently asked

What is Mode-S code A339B1?
A339B1 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N307DU.
Where is Mode-S A339B1 registered?
Mode-S code A339B1 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 A339B1 broadcasting right now?
Yes. Mode-S A339B1 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A339B1, octal 50634661, decimal 10,697,137.
What flights does A339B1 operate?
Mode-S A339B1 has broadcast 5 distinct callsigns, including DAL2231, DAL1116, DAL2413, DAL1614, DAL1423.