Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A991F4

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N7157G · CESSNA 172 Skyhawk · operated by AERO QUEST LLC, SAINT-GILLES LLC

Hex
A991F4
Octal
52310764
Decimal
11,112,948
Country
US
Tail
N7157G
Type
C172
No current signal · last broadcast Jul 26, 20:45 UTC
Flights observed
236
Distinct callsigns
1
Country
US
Last broadcast
Jul 26, 20:45 UTC

Last known position

Most recent position reported by Mode-S A991F4.

Country allocation

The ICAO 24-bit address A991F4 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 1 distinct

Callsign Airline Flights Last seen
N7157G - 236 2026-07-26

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 N7157G OLV → OLV Jul 26, 19:55 UTCJul 26, 20:45 UTC50m
2026-07-26 N7157G - Jul 26, 18:35 UTCJul 26, 18:50 UTC15m
2026-07-26 N7157G - Jul 26, 17:30 UTCJul 26, 17:45 UTC15m
2026-07-26 N7157G - Jul 26, 13:55 UTCJul 26, 14:55 UTC1h 0m
2026-07-25 N7157G - Jul 25, 00:55 UTCJul 25, 01:15 UTC20m
2026-07-24 N7157G - Jul 24, 23:50 UTCJul 25, 00:05 UTC15m
2026-07-24 N7157G - Jul 24, 22:40 UTCJul 24, 22:55 UTC15m
2026-07-24 N7157G - Jul 24, 21:35 UTCJul 24, 21:45 UTC10m
2026-07-24 N7157G OLV → OLV Jul 24, 13:50 UTCJul 24, 14:35 UTC45m
2026-07-24 N7157G - Jul 24, 11:45 UTCJul 24, 12:45 UTC1h 0m
2026-07-24 N7157G OLV → OLV Jul 24, 00:00 UTCJul 24, 00:35 UTC35m
2026-07-23 N7157G - Jul 23, 22:00 UTCJul 23, 22:20 UTC20m
2026-07-23 N7157G - Jul 23, 19:55 UTCJul 23, 20:40 UTC45m
2026-07-22 N7157G - Jul 22, 17:10 UTCJul 22, 17:30 UTC20m
2026-07-21 N7157G - Jul 21, 15:40 UTCJul 21, 16:20 UTC40m
2026-07-21 N7157G - Jul 21, 13:45 UTCJul 21, 14:45 UTC1h 0m
2026-07-21 N7157G - Jul 21, 12:15 UTCJul 21, 13:05 UTC50m
2026-07-20 N7157G - Jul 20, 14:50 UTCJul 20, 15:15 UTC25m
2026-07-20 N7157G - Jul 20, 13:45 UTCJul 20, 14:00 UTC15m
2026-07-19 N7157G - Jul 19, 13:30 UTCJul 19, 16:10 UTC2h 40m
2026-07-18 N7157G - Jul 18, 23:35 UTCJul 19, 00:35 UTC1h 0m
2026-07-18 N7157G - Jul 18, 17:50 UTCJul 18, 18:20 UTC30m
2026-07-18 N7157G - Jul 18, 13:55 UTCJul 18, 16:35 UTC2h 40m
2026-07-18 N7157G - Jul 18, 12:15 UTCJul 18, 13:00 UTC45m
2026-07-18 N7157G - Jul 18, 11:25 UTCJul 18, 11:40 UTC15m
2026-07-18 N7157G - Jul 18, 00:25 UTCJul 18, 00:45 UTC20m
2026-07-17 N7157G - Jul 17, 23:20 UTCJul 17, 23:30 UTC10m
2026-07-17 N7157G - Jul 17, 21:25 UTCJul 17, 22:15 UTC50m
2026-07-17 N7157G - Jul 17, 19:40 UTCJul 17, 20:20 UTC40m
2026-07-17 N7157G - Jul 17, 17:05 UTCJul 17, 17:25 UTC20m
2026-07-17 N7157G - Jul 17, 15:35 UTCJul 17, 15:49 UTC15m
2026-07-17 N7157G OLV → OLV Jul 17, 14:20 UTCJul 17, 14:55 UTC35m
2026-07-17 N7157G - Jul 17, 11:50 UTCJul 17, 12:30 UTC40m
2026-07-16 N7157G - Jul 16, 23:55 UTCJul 17, 00:45 UTC50m
2026-07-16 N7157G - Jul 16, 22:49 UTCJul 16, 23:05 UTC15m
2026-07-16 N7157G - Jul 16, 21:35 UTCJul 16, 21:45 UTC10m
2026-07-16 N7157G - Jul 16, 19:40 UTCJul 16, 20:29 UTC50m
2026-07-14 N7157G - Jul 14, 17:50 UTCJul 14, 18:30 UTC40m
2026-07-14 N7157G - Jul 14, 11:55 UTCJul 14, 12:40 UTC45m
2026-07-14 N7157G OLV → OLV Jul 14, 00:10 UTCJul 14, 00:50 UTC40m
2026-07-13 N7157G - Jul 13, 21:45 UTCJul 13, 22:45 UTC1h 0m
2026-07-13 N7157G - Jul 13, 20:40 UTCJul 13, 20:50 UTC10m
2026-07-13 N7157G - Jul 13, 19:40 UTCJul 13, 20:00 UTC20m
2026-07-13 N7157G OLV → OLV Jul 13, 17:40 UTCJul 13, 18:15 UTC35m
2026-07-13 N7157G - Jul 13, 13:55 UTCJul 13, 14:15 UTC20m
2026-07-13 N7157G OLV → OLV Jul 13, 12:05 UTCJul 13, 12:50 UTC45m
2026-07-12 N7157G OLV → OLV Jul 12, 19:40 UTCJul 12, 20:40 UTC1h 0m
2026-07-11 N7157G OLV → OLV Jul 11, 17:45 UTCJul 11, 18:25 UTC40m
2026-07-11 N7157G - Jul 11, 16:25 UTCJul 11, 16:45 UTC20m
2026-07-11 N7157G - Jul 11, 15:40 UTCJul 11, 15:50 UTC10m

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 N7157G page for operator, model, and routing details .

Mode-S A991F4 frequently asked

What is Mode-S code A991F4?
A991F4 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N7157G.
Where is Mode-S A991F4 registered?
Mode-S code A991F4 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 A991F4 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 20:45 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A991F4, octal 52310764, decimal 11,112,948.
What flights does A991F4 operate?
Mode-S A991F4 has broadcast 1 distinct callsign, including N7157G.