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sensors Mode-S transponder

781B2B

ICAO 24-bit transponder address · allocated to China

Currently assigned to B-125X · SUNWARD Aurora S60/70

Hex
781B2B
Octal
36015453
Decimal
7,871,275
Country
CN
Tail
B-125X
Type
AURA
No current signal · last broadcast Jul 25, 08:40 UTC
Flights observed
221
Distinct callsigns
20
Country
CN
Last broadcast
Jul 25, 08:40 UTC

Last known position

Most recent position reported by Mode-S 781B2B.

Country allocation

The ICAO 24-bit address 781B2B falls within the block assigned to China (CN) by ICAO Annex 10, Volume III. Every aircraft registered in China 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
HLF8821 - 36 2026-07-24
HLF8822 Hapagfly 30 2026-07-25
HLF8823 - 27 2026-07-22
HLF8824 Hapagfly 24 2026-07-23
HLF9859 - 14 2026-05-14
HLF9860 - 13 2026-05-14
HLF9836 Hapagfly 9 2026-07-21
HLF9835 Hapagfly 9 2026-07-20
HLF9872 - 8 2026-05-05
HLF9838 - 8 2026-05-12
HLF9837 - 8 2026-05-12
HLF9839 - 6 2026-05-08
HLF9802 - 6 2026-06-04
HLF9840 - 5 2026-05-08
HLF9817 - 5 2026-05-24
HLF9801 - 5 2026-06-01
HLF9871 - 2 2026-04-28
HLF9818 Hapagfly 2 2026-05-22
HLF9813 Hapagfly 2 2026-05-16
HLF9814 Hapagfly 1 2026-05-16

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-25 HLF8822 XCR → SZX Jul 25, 02:30 UTCJul 25, 08:40 UTC6h 10m
2026-07-24 HLF8821 - Jul 24, 16:05 UTCJul 24, 22:30 UTC6h 25m
2026-07-23 HLF8824 HAN → EHU Jul 23, 16:50 UTCJul 24, 16:45 UTC23h 55m
2026-07-23 HLF8824 HAN → EHU Jul 23, 15:30 UTCJul 23, 18:00 UTC2h 30m
2026-07-22 HLF8823 - Jul 22, 17:45 UTCJul 23, 11:45 UTC18h 0m
2026-07-22 HLF8823 - Jul 22, 15:15 UTCJul 23, 11:45 UTC20h 30m
2026-07-22 HLF8823 - Jul 22, 12:50 UTCJul 23, 11:45 UTC22h 55m
2026-07-22 HLF8822 - Jul 22, 11:45 UTCJul 23, 10:45 UTC23h 0m
2026-07-21 HLF9836 ONT → EHU Jul 21, 08:50 UTCJul 22, 04:45 UTC19h 55m
2026-07-21 HLF9836 ONT → EHU Jul 21, 07:30 UTCJul 22, 04:45 UTC21h 15m
2026-07-21 HLF9836 ONT → EHU Jul 21, 04:50 UTCJul 22, 04:45 UTC23h 55m
2026-07-21 HLF9836 ONT → EHU Jul 21, 04:40 UTCJul 22, 02:25 UTC21h 45m
2026-07-20 HLF9835 EHU → ANC Jul 20, 18:50 UTCJul 20, 23:40 UTC4h 50m
2026-07-20 HLF9835 EHU → ANC Jul 20, 09:35 UTCJul 20, 16:55 UTC7h 20m
2026-07-18 HLF8822 - Jul 18, 10:35 UTCJul 18, 16:40 UTC6h 5m
2026-07-18 HLF8821 - Jul 18, 01:25 UTCJul 18, 07:45 UTC6h 21m
2026-07-17 HLF8824 HAN → EHU Jul 17, 08:49 UTCJul 18, 07:45 UTC22h 56m
2026-07-17 HLF8824 HAN → EHU Jul 17, 08:10 UTCJul 18, 04:30 UTC20h 21m
2026-07-16 HLF8822 - Jul 16, 06:50 UTCJul 17, 00:35 UTC17h 45m
2026-07-15 HLF8821 - Jul 15, 21:40 UTCJul 16, 04:05 UTC6h 25m
2026-07-15 HLF9836 - Jul 15, 01:10 UTCJul 15, 22:30 UTC21h 20m
2026-07-14 HLF9836 - Jul 14, 15:00 UTCJul 15, 02:45 UTC11h 44m
2026-07-14 HLF9835 ANC → ONT Jul 14, 06:15 UTCJul 14, 10:45 UTC4h 30m
2026-07-13 HLF9835 - Jul 13, 20:50 UTCJul 14, 04:30 UTC7h 40m
2026-07-12 HLF8824 - Jul 12, 12:15 UTCJul 12, 18:35 UTC6h 20m
2026-07-12 HLF8823 - Jul 12, 02:20 UTCJul 12, 08:40 UTC6h 20m
2026-07-11 HLF8823 - Jul 11, 08:50 UTCJul 12, 08:40 UTC23h 50m
2026-07-11 HLF8822 - Jul 11, 02:50 UTCJul 12, 02:45 UTC23h 55m
2026-07-10 HLF8821 - Jul 10, 17:30 UTCJul 10, 23:50 UTC6h 20m
2026-07-09 HLF8821 - Jul 9, 23:50 UTCJul 10, 20:45 UTC20h 55m
2026-07-09 HLF8824 - Jul 9, 18:50 UTCJul 10, 18:15 UTC23h 25m
2026-07-09 HLF8824 - Jul 9, 17:45 UTCJul 10, 00:15 UTC6h 30m
2026-07-08 HLF8823 - Jul 8, 20:30 UTCJul 9, 14:10 UTC17h 40m
2026-07-08 HLF8823 - Jul 8, 16:50 UTCJul 9, 14:10 UTC21h 20m
2026-07-08 HLF8822 - Jul 8, 14:50 UTCJul 9, 14:10 UTC23h 20m
2026-07-08 HLF8822 - Jul 8, 14:35 UTCJul 9, 12:45 UTC22h 10m
2026-07-07 HLF8821 - Jul 7, 13:35 UTCJul 8, 07:55 UTC18h 20m
2026-07-07 HLF8821 - Jul 7, 08:50 UTCJul 8, 07:55 UTC23h 5m
2026-07-07 HLF9836 - Jul 7, 07:10 UTCJul 8, 06:45 UTC23h 35m
2026-07-07 HLF9836 - Jul 7, 04:50 UTCJul 8, 02:20 UTC21h 30m
2026-07-07 HLF9836 - Jul 7, 03:10 UTCJul 8, 02:20 UTC23h 10m
2026-07-06 HLF9835 ANC → ONT Jul 6, 18:55 UTCJul 6, 23:30 UTC4h 35m
2026-07-06 HLF9835 - Jul 6, 09:45 UTCJul 6, 17:10 UTC7h 25m
2026-07-05 HLF9835 - Jul 5, 18:50 UTCJul 6, 17:10 UTC22h 20m
2026-07-05 HLF9835 - Jul 5, 18:30 UTCJul 6, 16:45 UTC22h 15m
2026-07-05 HLF9835 - Jul 5, 14:50 UTCJul 6, 11:20 UTC20h 30m
2026-07-05 HLF8824 HAN → EHU Jul 5, 12:50 UTCJul 6, 11:20 UTC22h 30m
2026-07-05 HLF8824 HAN → EHU Jul 5, 12:35 UTCJul 6, 10:45 UTC22h 10m
2026-07-05 HLF8823 - Jul 5, 02:35 UTCJul 5, 09:00 UTC6h 25m
2026-07-04 HLF8823 - Jul 4, 11:05 UTCJul 5, 09:00 UTC21h 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 B-125X page for operator, model, and routing details .

Mode-S 781B2B frequently asked

What is Mode-S code 781B2B?
781B2B is an ICAO 24-bit transponder address. Allocated to China. Assigned to B-125X.
Where is Mode-S 781B2B registered?
Mode-S code 781B2B is allocated to China (CN). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 781B2B broadcasting right now?
No active broadcast right now. Last signal was Jul 25, 08:40 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 781B2B, octal 36015453, decimal 7,871,275.
What flights does 781B2B operate?
Mode-S 781B2B has broadcast 20 distinct callsigns, including HLF8821, HLF8822, HLF8823, HLF8824, HLF9859.