What is an ICAO24 address?
From a hex code to the aircraft behind it.
An ICAO24 address is a 24-bit aircraft address normally written as six hexadecimal characters, for example 47161A. It is widely encountered in Mode-S and ADS-B receiver logs, flight-tracking software, SBS/BaseStation data and historical aircraft databases.
This lookup uses the restored ACARSd and libhomeradar reference data. The recovered 2008 snapshot alone contains almost 19,000 historical ICAO24-to-registration mappings, including aircraft that have since been retired, deregistered or disappeared from modern fleet lists.
Useful search terms
Mode-S hex code • ICAO24 address • aircraft registration • tail number • aircraft type • construction number • airline/operator
Historical data is shown with its source date where available. A Mode-S address or registration may have changed during an aircraft's lifetime, so old mappings are preserved rather than silently overwritten.
ICAO24 result
4A2181 — 1 historical match
- Registration
- YR-HLA
- ICAO24 / Mode-S
- 4A2181
- Manufacturer
- Boeing
- Aircraft type
- 737-8HC
- ICAO type
- B738
- Construction number
- 36529/2008
- Operator
- Hello Jets
- Operator codes
- —
- Aircraft country
- —
- Historical mapping date
- —
- Mapping source
- standing-data
This machine in picture databases
Search external aviation photo archives using registration YR-HLA. These links use the registration only, not the ICAO24 address.
External databases may show a later operator or airframe history; the ACARSd mapping above remains the historical reference.Search historical ACARS messages for this ICAO24 →
About this database
A recovered historical source, not a current civil register.
The lookup combines restored ACARSd aircraft data with historical Mode-S/ICAO24 mappings recovered from the libhomeradar CVS archive. It is particularly useful for older registrations that may no longer appear in modern aircraft databases. Data should be read in its historical context and may contain errors inherited from the original community-maintained source.