sensors Mode-S transponder

8851E1

ICAO 24-bit transponder address · allocated to Thailand

Currently assigned to HS-TOA · AIRBUS A-321neo

Hex
8851E1
Octal
42050741
Decimal
8,933,857
Country
TH
Tail
HS-TOA
Type
A21N
No current signal · last broadcast 12h ago
Flights observed
14
Distinct callsigns
6
Country
TH
Last broadcast
12h ago

Last known position

Most recent position reported by Mode-S 8851E1.

Country allocation

The ICAO 24-bit address 8851E1 falls within the block assigned to Thailand (TH) by ICAO Annex 10, Volume III. Every aircraft registered in Thailand 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 6 distinct

Callsign Airline Flights Last seen
THA331 - 5 2026-04-13
THA332 Thai Airways International 4 2026-04-13
THA208 Thai Airways International 2 2026-04-14
THA636 Thai Airways International 1 2026-04-14
THA250 - 1 2026-04-13
THA249 Thai Airways International 1 2026-04-13

Recent flights last 14

DateFlightRouteTakeoffLandingDuration
2026-04-14 THA636 BKK → TPE Apr 14, 10:35 UTCApr 14, 10:55 UTC20m
2026-04-14 THA208 HKT → BKK Apr 14, 07:10 UTCApr 14, 07:20 UTC10m
2026-04-14 THA208 HKT → BKK Apr 14, 06:35 UTCApr 14, 07:10 UTC35m
2026-04-13 THA332 DEL → BKK Apr 13, 22:20 UTCApr 13, 23:45 UTC1h 25m
2026-04-13 THA331 - Apr 13, 19:50 UTCApr 13, 20:50 UTC1h 0m
2026-04-13 THA331 - Apr 13, 18:10 UTCApr 13, 20:10 UTC2h 0m
2026-04-13 THA331 - Apr 13, 16:45 UTCApr 13, 16:55 UTC10m
2026-04-13 THA250 - Apr 13, 12:20 UTCApr 13, 14:55 UTC2h 35m
2026-04-13 THA249 BKK → KBV Apr 13, 11:50 UTCApr 13, 12:10 UTC20m
2026-04-13 THA332 DEL → BKK Apr 13, 02:15 UTCApr 13, 02:45 UTC30m
2026-04-13 THA332 DEL → BKK Apr 13, 00:20 UTCApr 13, 01:30 UTC1h 10m
2026-04-12 THA332 DEL → BKK Apr 12, 23:55 UTCApr 13, 01:30 UTC1h 35m
2026-04-12 THA331 - Apr 12, 18:30 UTCApr 12, 20:15 UTC1h 45m
2026-04-12 THA331 - Apr 12, 17:15 UTCApr 12, 17:30 UTC15m

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 HS-TOA page for operator, model, and routing details .

Mode-S 8851E1 frequently asked

What is Mode-S code 8851E1?
8851E1 is an ICAO 24-bit transponder address. Allocated to Thailand. Assigned to HS-TOA.
Where is Mode-S 8851E1 registered?
Mode-S code 8851E1 is allocated to Thailand (TH). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8851E1 broadcasting right now?
No active broadcast right now. Last signal was 12h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 8851E1, octal 42050741, decimal 8,933,857.
What flights does 8851E1 operate?
Mode-S 8851E1 has broadcast 6 distinct callsigns, including THA331, THA332, THA208, THA636, THA250.