sensors Mode-S transponder

ACF27F

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N933TH · operated by AEROSTAR

Hex
ACF27F
Octal
53171177
Decimal
11,334,271
Country
US
Tail
N933TH
Broadcasting now · callsign HBAL793 · 62,000 ft
Flights observed
6
Distinct callsigns
1
Country
US
Last broadcast
1h ago

Current position

ACF27F is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address ACF27F 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
HBAL793 - 6 2026-04-18

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-18 HBAL793 - Apr 18, 13:50 UTCApr 19, 13:45 UTC23h 55m
2026-04-18 HBAL793 - Apr 18, 11:50 UTCApr 19, 11:45 UTC23h 55m
2026-04-18 HBAL793 - Apr 18, 09:50 UTCApr 19, 09:45 UTC23h 55m
2026-04-18 HBAL793 - Apr 18, 07:50 UTCApr 19, 07:45 UTC23h 55m
2026-04-18 HBAL793 - Apr 18, 07:25 UTCApr 18, 09:20 UTC1h 55m
2026-04-18 HBAL793 - Apr 18, 06:50 UTCApr 19, 05:45 UTC22h 55m

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 N933TH page for operator, model, and routing details .

Mode-S ACF27F frequently asked

What is Mode-S code ACF27F?
ACF27F is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N933TH.
Where is Mode-S ACF27F registered?
Mode-S code ACF27F 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 ACF27F broadcasting right now?
Yes. Mode-S ACF27F is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex ACF27F, octal 53171177, decimal 11,334,271.
What flights does ACF27F operate?
Mode-S ACF27F has broadcast 1 distinct callsign, including HBAL793.