Apparatus

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sensors Mode-S transponder

A999DF

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N718BA · BOEING 747-400LCF Dreamlifter · operated by BOEING AIRCRAFT HOLDING CO

Hex
A999DF
Octal
52314737
Decimal
11,114,975
Country
US
Tail
N718BA
Type
BLCF
Broadcasting now · callsign GTI4546 · 34,000 ft
Flights observed
76
Distinct callsigns
12
Country
US
Last broadcast
Jul 24, 19:45 UTC

Current position

A999DF is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A999DF 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 12 distinct

Callsign Airline Flights Last seen
GTI4536 Atlas Air 19 2026-07-24
GTI4316 Atlas Air 12 2026-07-23
GTI4546 Atlas Air 8 2026-06-23
GTI4431 Atlas Air 7 2026-06-23
GTI4231 - 7 2026-07-11
GTI4326 - 6 2026-07-10
GTI4531 - 5 2026-07-18
GTI4312 - 4 2026-07-15
GTI4542 - 3 2026-06-30
GTI4436 Atlas Air 2 2026-05-14
GTI4432 Atlas Air 2 2026-06-30
GTI4451 Atlas Air 1 2026-05-12

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-24 GTI4536 ANC → CHS Jul 24, 13:00 UTCJul 24, 19:45 UTC6h 45m
2026-07-24 GTI4536 ANC → CHS Jul 24, 04:20 UTCJul 24, 10:45 UTC6h 25m
2026-07-23 GTI4316 PAE → NGO Jul 23, 17:25 UTCJul 24, 00:50 UTC7h 25m
2026-07-23 GTI4316 PAE → NGO Jul 23, 07:15 UTCJul 23, 14:55 UTC7h 40m
2026-07-21 GTI4536 ANC → CHS Jul 21, 18:35 UTCJul 22, 00:50 UTC6h 15m
2026-07-21 GTI4536 ANC → CHS Jul 21, 10:05 UTCJul 21, 16:25 UTC6h 20m
2026-07-20 GTI4316 PAE → NGO Jul 20, 22:50 UTCJul 21, 06:10 UTC7h 19m
2026-07-20 GTI4316 PAE → NGO Jul 20, 13:20 UTCJul 20, 21:00 UTC7h 40m
2026-07-18 GTI4531 - Jul 18, 13:15 UTCJul 18, 19:35 UTC6h 20m
2026-07-18 GTI4531 - Jul 18, 04:20 UTCJul 18, 11:00 UTC6h 40m
2026-07-15 GTI4312 - Jul 15, 16:10 UTCJul 15, 22:45 UTC6h 35m
2026-07-15 GTI4312 - Jul 15, 06:35 UTCJul 15, 13:35 UTC7h 0m
2026-07-11 GTI4231 - Jul 11, 07:30 UTCJul 11, 17:35 UTC10h 5m
2026-07-10 GTI4326 - Jul 10, 02:30 UTCJul 10, 11:50 UTC9h 20m
2026-07-09 GTI4231 - Jul 9, 16:05 UTCJul 9, 17:20 UTC1h 15m
2026-07-09 GTI4231 - Jul 9, 07:15 UTCJul 9, 16:00 UTC8h 45m
2026-07-08 GTI4326 - Jul 8, 03:25 UTCJul 8, 12:35 UTC9h 10m
2026-07-05 GTI4536 - Jul 5, 18:55 UTCJul 6, 01:30 UTC6h 35m
2026-07-05 GTI4536 - Jul 5, 09:20 UTCJul 5, 16:00 UTC6h 40m
2026-07-04 GTI4316 - Jul 4, 20:40 UTCJul 5, 03:40 UTC7h 0m
2026-07-04 GTI4316 - Jul 4, 11:20 UTCJul 4, 18:15 UTC6h 55m
2026-06-30 GTI4432 PAE → CHS Jun 30, 21:50 UTCJul 1, 02:30 UTC4h 40m
2026-06-30 GTI4542 - Jun 30, 10:15 UTCJun 30, 15:10 UTC4h 55m
2026-06-29 GTI4536 ANC → CHS Jun 29, 07:25 UTCJun 29, 14:19 UTC6h 55m
2026-06-28 GTI4536 - Jun 28, 23:04 UTCJun 29, 05:24 UTC6h 20m
2026-06-27 GTI4312 - Jun 27, 23:34 UTCJun 28, 06:55 UTC7h 20m
2026-06-27 GTI4312 - Jun 27, 11:14 UTCJun 27, 18:35 UTC7h 20m
2026-06-23 GTI4431 IAB → CHS Jun 23, 23:50 UTCJun 24, 01:55 UTC2h 5m
2026-06-23 GTI4546 ANC → LAX Jun 23, 18:34 UTCJun 23, 20:59 UTC2h 25m
2026-06-22 GTI4231 TAR → CHS Jun 22, 07:19 UTCJun 22, 17:44 UTC10h 25m
2026-06-21 GTI4326 CHS → TAR Jun 21, 02:24 UTCJun 21, 11:40 UTC9h 15m
2026-06-19 GTI4231 TAR → CHS Jun 19, 09:34 UTCJun 19, 20:19 UTC10h 45m
2026-06-16 GTI4326 CHS → TAR Jun 16, 03:50 UTCJun 16, 13:00 UTC9h 10m
2026-06-12 GTI4231 TAR → CHS Jun 12, 13:45 UTCJun 12, 23:50 UTC10h 5m
2026-06-11 GTI4326 CHS → TAR Jun 11, 02:35 UTCJun 11, 11:40 UTC9h 5m
2026-06-09 GTI4431 IAB → CHS Jun 9, 23:50 UTCJun 10, 01:50 UTC2h 0m
2026-06-09 GTI4546 ANC → LAX Jun 9, 17:45 UTCJun 9, 19:50 UTC2h 5m
2026-06-04 GTI4536 ANC → CHS Jun 4, 19:30 UTCJun 5, 02:15 UTC6h 45m
2026-06-04 GTI4536 ANC → CHS Jun 4, 10:30 UTCJun 4, 17:20 UTC6h 50m
2026-06-03 GTI4316 PAE → NGO Jun 3, 21:50 UTCJun 4, 04:50 UTC7h 0m
2026-06-03 GTI4316 PAE → NGO Jun 3, 12:35 UTCJun 3, 19:45 UTC7h 10m
2026-06-03 GTI4431 IAB → CHS Jun 3, 01:35 UTCJun 3, 03:35 UTC2h 0m
2026-06-02 GTI4546 ANC → LAX Jun 2, 20:30 UTCJun 2, 21:40 UTC1h 10m
2026-06-02 GTI4546 ANC → LAX Jun 2, 19:20 UTCJun 2, 20:25 UTC1h 5m
2026-06-01 GTI4431 IAB → CHS Jun 1, 04:30 UTCJun 1, 06:25 UTC1h 55m
2026-05-31 GTI4546 ANC → LAX May 31, 19:25 UTCMay 31, 21:45 UTC2h 20m
2026-05-26 GTI4536 ANC → CHS May 26, 16:10 UTCMay 26, 22:50 UTC6h 40m
2026-05-26 GTI4536 ANC → CHS May 26, 03:30 UTCMay 26, 10:14 UTC6h 45m
2026-05-23 GTI4316 PAE → NGO May 23, 00:05 UTCMay 23, 07:25 UTC7h 19m
2026-05-22 GTI4316 PAE → NGO May 22, 14:35 UTCMay 22, 21:55 UTC7h 20m

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 N718BA page for operator, model, and routing details .

Mode-S A999DF frequently asked

What is Mode-S code A999DF?
A999DF is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N718BA.
Where is Mode-S A999DF registered?
Mode-S code A999DF 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 A999DF broadcasting right now?
Yes. Mode-S A999DF is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A999DF, octal 52314737, decimal 11,114,975.
What flights does A999DF operate?
Mode-S A999DF has broadcast 12 distinct callsigns, including GTI4536, GTI4316, GTI4546, GTI4431, GTI4231.