Apparatus

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sensors Mode-S transponder

A11A81

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N170PQ · BOMBARDIER Regional Jet CRJ-900 · operated by DELTA AIR LINES INC

Hex
A11A81
Octal
50215201
Decimal
10,558,081
Country
US
Tail
N170PQ
Type
CRJ9
No current signal · last broadcast Jul 26, 22:15 UTC
Flights observed
688
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:15 UTC

Last known position

Most recent position reported by Mode-S A11A81.

Country allocation

The ICAO 24-bit address A11A81 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 20 distinct

Callsign Airline Flights Last seen
SKW3971 - 19 2026-07-17
SKW3990 - 16 2026-07-08
SKW3851 - 15 2026-07-17
SKW4130 SkyWest Airlines 14 2026-07-19
SKW4456 SkyWest Airlines 13 2026-06-18
SKW4055 SkyWest Airlines 12 2026-06-24
SKW3702 - 12 2026-07-20
SKW4066 - 10 2026-07-21
SKW3920 SkyWest Airlines 10 2026-07-26
SKW3835 SkyWest Airlines 10 2026-07-22
SKW4065 - 9 2026-06-25
SKW4051 SkyWest Airlines 9 2026-05-15
SKW3886 SkyWest Airlines 9 2026-07-22
SKW3785 - 9 2026-06-25
SKW4144 - 8 2026-07-16
SKW4103 SkyWest Airlines 8 2026-07-06
SKW4079 SkyWest Airlines 8 2026-05-21
SKW4032 SkyWest Airlines 8 2026-05-21
SKW3967 - 8 2026-07-08
SKW3961 - 8 2026-06-20

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SKW3538 ATL → LEX Jul 26, 21:40 UTCJul 26, 22:15 UTC35m
2026-07-26 SKW3538 ATL → LEX Jul 26, 19:55 UTCJul 26, 20:30 UTC35m
2026-07-26 SKW3920 MDW → MSP Jul 26, 17:20 UTCJul 26, 18:10 UTC50m
2026-07-26 SKW129W FWA → ATL Jul 26, 15:35 UTCJul 26, 16:20 UTC45m
2026-07-26 SKW3927 BTV → DTW Jul 26, 13:10 UTCJul 26, 14:05 UTC55m
2026-07-26 SKW3714 SLC → LGB Jul 26, 02:55 UTCJul 26, 04:10 UTC1h 15m
2026-07-25 SKW3948 HPN → ATL Jul 25, 23:10 UTCJul 26, 00:00 UTC50m
2026-07-25 SKW188F MSP → OMA Jul 25, 21:10 UTCJul 25, 22:00 UTC50m
2026-07-25 SKW149R YYZ → MSP Jul 25, 17:25 UTCJul 25, 19:05 UTC1h 40m
2026-07-25 SKW139W ORD → BOS Jul 25, 13:40 UTCJul 25, 15:15 UTC1h 35m
2026-07-25 SKW3840 SEA → SJC Jul 25, 11:31 UTCJul 25, 12:07 UTC36m
2026-07-25 SKW3840 SEA → SJC Jul 25, 11:35 UTCJul 25, 12:10 UTC35m
2026-07-25 SKW3578 LWS → SLC Jul 25, 00:05 UTCJul 25, 00:40 UTC35m
2026-07-24 SKW3865 SJC → SEA Jul 24, 21:55 UTCJul 24, 23:05 UTC1h 10m
2026-07-24 SKW3865 SJC → SEA Jul 24, 19:55 UTCJul 24, 20:50 UTC55m
2026-07-24 SKW3995 IND → DTW Jul 24, 17:55 UTCJul 24, 18:55 UTC1h 0m
2026-07-24 SKW3995 IND → DTW Jul 24, 15:35 UTCJul 24, 16:20 UTC45m
2026-07-24 SKW4136 SJC → LAX Jul 24, 13:10 UTCJul 24, 13:55 UTC45m
2026-07-24 SKW4154 MSP → CMH Jul 24, 03:20 UTCJul 24, 04:15 UTC55m
2026-07-23 SKW3709 JFK → BNA Jul 23, 23:55 UTCJul 24, 01:50 UTC1h 55m
2026-07-23 SKW3709 JFK → BNA Jul 23, 23:58 UTCJul 24, 01:44 UTC1h 46m
2026-07-23 SKW3709 JFK → BNA Jul 23, 21:40 UTCJul 23, 23:00 UTC1h 20m
2026-07-23 SKW4089 SFO → SEA Jul 23, 19:00 UTCJul 23, 20:30 UTC1h 30m
2026-07-23 SKW4089 SFO → SEA Jul 23, 16:15 UTCJul 23, 18:00 UTC1h 45m
2026-07-23 SKW4136 SJC → LAX Jul 23, 13:05 UTCJul 23, 13:55 UTC50m
2026-07-22 SKW4143 DTW → BUF Jul 22, 23:44 UTCJul 23, 00:34 UTC50m
2026-07-22 SKW4143 DTW → BUF Jul 22, 23:25 UTCJul 23, 00:15 UTC50m
2026-07-22 SKW3595 ATL → CHA Jul 22, 21:00 UTCJul 22, 22:15 UTC1h 15m
2026-07-22 SKW3595 ATL → CHA Jul 22, 21:03 UTCJul 22, 22:13 UTC1h 10m
2026-07-22 SKW3595 ATL → CHA Jul 22, 18:40 UTCJul 22, 19:55 UTC1h 15m
2026-07-22 SKW3831 OMA → MSP Jul 22, 16:05 UTCJul 22, 16:55 UTC50m
2026-07-22 SKW3831 MSP → OMA Jul 22, 14:00 UTCJul 22, 14:45 UTC45m
2026-07-22 SKW3835 FAR → MSP Jul 22, 11:25 UTCJul 22, 12:35 UTC1h 10m
2026-07-22 SKW3886 LGA → MKE Jul 22, 01:15 UTCJul 22, 02:10 UTC55m
2026-07-21 SKW4066 - Jul 21, 16:35 UTCJul 21, 17:20 UTC45m
2026-07-21 SKW4066 - Jul 21, 14:10 UTCJul 21, 15:05 UTC55m
2026-07-21 SKW3835 FAR → MSP Jul 21, 11:50 UTCJul 21, 13:05 UTC1h 15m
2026-07-21 SKW3886 LGA → MKE Jul 21, 01:25 UTCJul 21, 02:15 UTC50m
2026-07-20 SKW3861 ATW → MSP Jul 20, 21:30 UTCJul 20, 22:20 UTC50m
2026-07-20 SKW3861 MSP → ATW Jul 20, 19:40 UTCJul 20, 20:25 UTC45m
2026-07-20 SKW4066 - Jul 20, 16:35 UTCJul 20, 17:40 UTC1h 5m
2026-07-20 SKW4066 - Jul 20, 14:10 UTCJul 20, 15:05 UTC55m
2026-07-20 SKW3702 - Jul 20, 11:20 UTCJul 20, 12:55 UTC1h 35m
2026-07-20 SKW3702 FWA → MSP Jul 20, 11:20 UTCJul 20, 12:53 UTC1h 33m
2026-07-20 SKW3780 - Jul 20, 01:15 UTCJul 20, 02:05 UTC50m
2026-07-19 SKW4130 PDX → SEA Jul 19, 23:05 UTCJul 19, 23:55 UTC50m
2026-07-19 SKW4130 PDX → SEA Jul 19, 23:06 UTCJul 19, 23:55 UTC49m
2026-07-19 SKW4130 PDX → SEA Jul 19, 20:50 UTCJul 19, 21:50 UTC1h 0m
2026-07-19 SKW4089 COS → MSP Jul 19, 18:00 UTCJul 19, 19:40 UTC1h 40m
2026-07-19 SKW4089 MSP → COS Jul 19, 14:35 UTCJul 19, 16:15 UTC1h 40m

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 N170PQ page for operator, model, and routing details .

Mode-S A11A81 frequently asked

What is Mode-S code A11A81?
A11A81 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N170PQ.
Where is Mode-S A11A81 registered?
Mode-S code A11A81 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 A11A81 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 22:15 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A11A81, octal 50215201, decimal 10,558,081.
What flights does A11A81 operate?
Mode-S A11A81 has broadcast 20 distinct callsigns, including SKW3971, SKW3990, SKW3851, SKW4130, SKW4456.