sensors Mode-S transponder

A81EE1

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N622NK · AIRBUS A-320 · operated by WILMINGTON TRUST CO TRUSTEE

Hex
A81EE1
Octal
52017341
Decimal
11,017,953
Country
US
Tail
N622NK
Type
A320
Photo of N622NK
Broadcasting now · callsign NKS274 · 23,000 ft
Flights observed
10
Distinct callsigns
5
Country
US
Last broadcast
14h ago

Current position

A81EE1 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A81EE1 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
NKS2230 Spirit Airlines 3 2026-04-13
NKS1071 - 3 2026-04-13
NKS273 - 2 2026-04-13
NKS831 - 1 2026-04-13
NKS450 - 1 2026-04-14

Recent flights last 10

DateFlightRouteTakeoffLandingDuration
2026-04-14 NKS450 - Apr 14, 10:15 UTCApr 14, 11:05 UTC50m
2026-04-13 NKS273 - Apr 13, 21:25 UTCApr 13, 23:45 UTC2h 20m
2026-04-13 NKS2230 PHL → IAH Apr 13, 19:50 UTCApr 13, 20:05 UTC15m
2026-04-13 NKS2230 PHL → IAH Apr 13, 17:20 UTCApr 13, 20:05 UTC2h 45m
2026-04-13 NKS831 EWR → FLL Apr 13, 12:25 UTCApr 13, 14:55 UTC2h 30m
2026-04-13 NKS1071 - Apr 13, 04:20 UTCApr 13, 05:10 UTC50m
2026-04-13 NKS1071 - Apr 13, 03:55 UTCApr 13, 05:10 UTC1h 15m
2026-04-13 NKS1071 - Apr 13, 02:56 UTCApr 13, 05:07 UTC2h 11m
2026-04-12 NKS273 - Apr 12, 23:55 UTCApr 13, 00:05 UTC10m
2026-04-12 NKS2230 PHL → IAH Apr 12, 17:15 UTCApr 12, 20:05 UTC2h 50m

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 N622NK page for operator, model, and routing details .

Mode-S A81EE1 frequently asked

What is Mode-S code A81EE1?
A81EE1 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N622NK.
Where is Mode-S A81EE1 registered?
Mode-S code A81EE1 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 A81EE1 broadcasting right now?
Yes. Mode-S A81EE1 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A81EE1, octal 52017341, decimal 11,017,953.
What flights does A81EE1 operate?
Mode-S A81EE1 has broadcast 5 distinct callsigns, including NKS2230, NKS1071, NKS273, NKS831, NKS450.