Apparatus

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sensors Mode-S transponder

7C78A9

ICAO 24-bit transponder address · allocated to Australia

Currently assigned to VH-X4B · AIRBUS A220-300

Hex
7C78A9
Octal
37074251
Decimal
8,157,353
Country
AU
Tail
VH-X4B
Type
BCS3
No current signal · last broadcast 29m ago
Flights observed
355
Distinct callsigns
20
Country
AU
Last broadcast
29m ago

Last known position

Most recent position reported by Mode-S 7C78A9.

Country allocation

The ICAO 24-bit address 7C78A9 falls within the block assigned to Australia (AU) by ICAO Annex 10, Volume III. Every aircraft registered in Australia 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
QLK1575 - 12 2026-07-07
QLK1574 - 12 2026-07-07
QLK1573 - 12 2026-06-30
QLK1572 - 11 2026-06-29
QLK1506 - 11 2026-07-05
QLK1504 - 10 2026-06-27
QLK1284 - 9 2026-07-09
QLK1283 - 9 2026-07-09
QLK1258 - 9 2026-07-08
QLK1576 - 8 2026-07-04
QLK1515 - 8 2026-06-25
QLK1514 - 8 2026-06-25
QLK1259 - 8 2026-06-16
QLK1581 - 7 2026-07-04
QLK1554 - 7 2026-07-14
QLK1530 - 7 2026-07-06
QLK1519 - 7 2026-07-12
QLK1296 - 7 2026-07-08
QLK282 - 6 2026-06-20
QLK1580 - 6 2026-07-04

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 QLK1554 - Jul 14, 05:10 UTCJul 14, 08:15 UTC3h 5m
2026-07-13 QLK1562 BNE → BNE Jul 13, 22:40 UTCJul 14, 03:50 UTC5h 10m
2026-07-13 QLK1256 MEL → BNE Jul 13, 09:10 UTCJul 13, 11:05 UTC1h 55m
2026-07-13 QLK1294 MEL → MEL Jul 13, 02:35 UTCJul 13, 05:31 UTC2h 55m
2026-07-13 QLK1558 - Jul 13, 00:30 UTCJul 13, 01:10 UTC40m
2026-07-12 QLK1557 - Jul 12, 22:25 UTCJul 12, 22:55 UTC30m
2026-07-12 QLK1519 - Jul 12, 20:10 UTCJul 12, 21:05 UTC55m
2026-07-12 QLK1517 - Jul 12, 09:25 UTCJul 12, 10:55 UTC1h 30m
2026-07-12 QLK1593 - Jul 12, 04:55 UTCJul 12, 06:10 UTC1h 15m
2026-07-12 QLK1592 - Jul 12, 02:20 UTCJul 12, 03:40 UTC1h 20m
2026-07-11 QLK1282 - Jul 11, 04:35 UTCJul 11, 06:30 UTC1h 55m
2026-07-11 QLK1281 BNE → ADL Jul 11, 01:00 UTCJul 11, 03:30 UTC2h 30m
2026-07-10 QLK1516 - Jul 10, 22:15 UTCJul 10, 23:40 UTC1h 25m
2026-07-10 QLK1517 - Jul 10, 09:25 UTCJul 10, 10:50 UTC1h 25m
2026-07-10 QLK1593 - Jul 10, 05:20 UTCJul 10, 06:30 UTC1h 10m
2026-07-10 QLK1592 - Jul 10, 02:30 UTCJul 10, 04:00 UTC1h 30m
2026-07-09 QLK1546 BNE → BNE Jul 9, 20:50 UTCJul 10, 01:10 UTC4h 20m
2026-07-09 QLK1284 ADL → BNE Jul 9, 10:20 UTCJul 9, 12:35 UTC2h 15m
2026-07-09 QLK1283 BNE → ADL Jul 9, 05:10 UTCJul 9, 07:35 UTC2h 25m
2026-07-08 QLK1562 BNE → BNE Jul 8, 22:40 UTCJul 9, 03:40 UTC5h 0m
2026-07-08 QLK1258 - Jul 8, 10:40 UTCJul 8, 12:35 UTC1h 55m
2026-07-08 QLK1296 - Jul 8, 06:35 UTCJul 8, 09:40 UTC3h 5m
2026-07-08 QLK1597 - Jul 8, 02:50 UTCJul 8, 05:20 UTC2h 30m
2026-07-07 QLK1596 - Jul 7, 22:40 UTCJul 8, 01:15 UTC2h 35m
2026-07-07 QLK1290 - Jul 7, 11:20 UTCJul 7, 21:10 UTC9h 50m
2026-07-07 QLK1575 - Jul 7, 08:10 UTCJul 7, 10:20 UTC2h 10m
2026-07-07 QLK1574 - Jul 7, 05:05 UTCJul 7, 06:50 UTC1h 45m
2026-07-07 QLK1523 - Jul 7, 01:40 UTCJul 7, 02:45 UTC1h 5m
2026-07-06 QLK1520 - Jul 6, 22:40 UTCJul 6, 23:30 UTC50m
2026-07-06 QLK1519 - Jul 6, 20:20 UTCJul 6, 21:10 UTC50m
2026-07-06 QLK1530 - Jul 6, 10:30 UTCJul 6, 11:20 UTC50m
2026-07-06 QLK1296 - Jul 6, 06:20 UTCJul 6, 09:20 UTC3h 0m
2026-07-05 QLK1599 - Jul 5, 22:45 UTCJul 6, 04:40 UTC5h 55m
2026-07-05 QLK1507 SYD → MEL Jul 5, 10:05 UTCJul 5, 21:15 UTC11h 10m
2026-07-05 QLK1506 - Jul 5, 04:35 UTCJul 5, 08:45 UTC4h 10m
2026-07-04 QLK1581 SYD → SYD Jul 4, 23:00 UTCJul 5, 03:15 UTC4h 15m
2026-07-04 QLK1581 - Jul 4, 07:35 UTCJul 4, 08:55 UTC1h 20m
2026-07-04 QLK1580 - Jul 4, 05:20 UTCJul 4, 06:40 UTC1h 20m
2026-07-04 QLK1577 - Jul 4, 02:45 UTCJul 4, 04:05 UTC1h 20m
2026-07-04 QLK1576 - Jul 4, 00:10 UTCJul 4, 01:30 UTC1h 20m
2026-07-03 QLK1579 MCY → SYD Jul 3, 21:05 UTCJul 3, 22:25 UTC1h 20m
2026-07-03 QLK1578 SYD → MCY Jul 3, 10:20 UTCJul 3, 11:40 UTC1h 20m
2026-07-03 QLK1534 - Jul 3, 04:25 UTCJul 3, 08:30 UTC4h 5m
2026-07-03 QLK1533 - Jul 3, 02:25 UTCJul 3, 03:15 UTC50m
2026-07-03 QLK1532 - Jul 3, 00:35 UTCJul 3, 01:10 UTC35m
2026-07-02 QLK1508 - Jul 2, 10:55 UTCJul 2, 23:15 UTC12h 20m
2026-07-02 QLK1529 - Jul 2, 08:40 UTCJul 2, 09:40 UTC1h 0m
2026-07-02 QLK1526 - Jul 2, 06:55 UTCJul 2, 07:35 UTC40m
2026-07-02 QLK1525 - Jul 2, 04:40 UTCJul 2, 05:40 UTC1h 0m
2026-07-02 QLK1522 - Jul 2, 03:05 UTCJul 2, 03:40 UTC35m

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 VH-X4B page for operator, model, and routing details .

Mode-S 7C78A9 frequently asked

What is Mode-S code 7C78A9?
7C78A9 is an ICAO 24-bit transponder address. Allocated to Australia. Assigned to VH-X4B.
Where is Mode-S 7C78A9 registered?
Mode-S code 7C78A9 is allocated to Australia (AU). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 7C78A9 broadcasting right now?
No active broadcast right now. Last signal was 29m ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 7C78A9, octal 37074251, decimal 8,157,353.
What flights does 7C78A9 operate?
Mode-S 7C78A9 has broadcast 20 distinct callsigns, including QLK1575, QLK1574, QLK1573, QLK1572, QLK1506.