Apparatus

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sensors Mode-S transponder

AA739E

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N77259 · BOEING 737 MAX 8 · operated by WILMINGTON TRUST CO TRUSTEE

Hex
AA739E
Octal
52471636
Decimal
11,170,718
Country
US
Tail
N77259
Type
B38M
No current signal · last broadcast Jul 26, 19:50 UTC
Flights observed
465
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 19:50 UTC

Last known position

Most recent position reported by Mode-S AA739E.

Country allocation

The ICAO 24-bit address AA739E 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 20 distinct

Callsign Airline Flights Last seen
UAL2185 United Airlines 8 2026-05-11
UAL1368 United Airlines 8 2026-07-17
UAL2021 - 7 2026-07-17
UAL1918 - 5 2026-06-25
UAL1784 - 5 2026-07-15
UAL757 United Airlines 4 2026-05-07
UAL663 United Airlines 4 2026-05-10
UAL346 United Airlines 4 2026-06-16
UAL278 United Airlines 4 2026-07-07
UAL2677 - 4 2026-06-27
UAL2271 United Airlines 4 2026-06-08
UAL1876 - 4 2026-06-25
UAL1596 - 4 2026-06-21
UAL1443 United Airlines 4 2026-05-24
UAL840 United Airlines 3 2026-06-09
UAL608 - 3 2026-04-13
UAL564 - 3 2026-06-15
UAL464 United Airlines 3 2026-04-17
UAL453 - 3 2026-04-14
UAL361 - 3 2026-06-26

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL1045 DEN → IAD Jul 26, 19:35 UTCJul 26, 19:50 UTC15m
2026-07-26 UAL2246 RSW → EWR Jul 26, 15:20 UTCJul 26, 18:05 UTC2h 45m
2026-07-26 UAL2246 RSW → EWR Jul 26, 15:22 UTCJul 26, 17:58 UTC2h 36m
2026-07-26 UAL1833 MCO → EWR Jul 26, 12:45 UTCJul 26, 13:50 UTC1h 5m
2026-07-25 UAL1446 LIR → EWR Jul 25, 23:20 UTCJul 26, 03:45 UTC4h 25m
2026-07-25 UAL1917 DEN → LIR Jul 25, 16:30 UTCJul 25, 20:30 UTC4h 0m
2026-07-25 UAL1917 DEN → LIR Jul 25, 16:29 UTCJul 25, 21:08 UTC4h 39m
2026-07-25 UAL1716 PHL → DEN Jul 25, 12:20 UTCJul 25, 14:35 UTC2h 15m
2026-07-24 UAL1300 ATL → ORD Jul 24, 23:50 UTCJul 25, 01:55 UTC2h 5m
2026-07-24 UAL2350 SAN → ORD Jul 24, 20:15 UTCJul 24, 22:10 UTC1h 55m
2026-07-24 UAL2350 SAN → ORD Jul 24, 20:16 UTCJul 24, 22:05 UTC1h 49m
2026-07-24 UAL2153 DEN → SNA Jul 24, 17:45 UTCJul 24, 18:45 UTC1h 0m
2026-07-24 UAL1597 LAX → SFO Jul 24, 11:10 UTCJul 24, 15:45 UTC4h 35m
2026-07-24 UAL1939 EWR → PBI Jul 24, 05:00 UTCJul 24, 08:50 UTC3h 50m
2026-07-24 UAL2841 DEN → IAH Jul 24, 00:55 UTCJul 24, 02:05 UTC1h 10m
2026-07-23 UAL2855 EWR → SFO Jul 23, 21:40 UTCJul 23, 22:55 UTC1h 15m
2026-07-23 UAL2619 DEN → MSP Jul 23, 18:45 UTCJul 23, 20:20 UTC1h 35m
2026-07-23 UAL2374 SFO → PHX Jul 23, 15:15 UTCJul 23, 16:45 UTC1h 30m
2026-07-23 UAL1685 LIH → DEN Jul 23, 12:45 UTCJul 23, 13:30 UTC45m
2026-07-23 UAL1684 SFO → LIH Jul 23, 00:30 UTCJul 23, 05:30 UTC5h 0m
2026-07-22 UAL1958 RDU → EWR Jul 22, 03:50 UTCJul 22, 21:40 UTC17h 50m
2026-07-22 UAL1230 YVR → SFO Jul 22, 00:30 UTCJul 22, 02:18 UTC1h 48m
2026-07-22 UAL1230 YVR → SFO Jul 22, 00:30 UTCJul 22, 02:35 UTC2h 5m
2026-07-21 UAL1134 EWR → CUN Jul 21, 17:00 UTCJul 21, 23:00 UTC6h 0m
2026-07-21 UAL798 DEN → RNO Jul 21, 11:25 UTCJul 21, 12:50 UTC1h 25m
2026-07-21 UAL798 DEN → RNO Jul 21, 11:26 UTCJul 21, 12:42 UTC1h 16m
2026-07-20 UAL2104 DCA → DEN Jul 20, 23:20 UTCJul 21, 00:35 UTC1h 14m
2026-07-20 UAL1845 SLC → EWR Jul 20, 17:30 UTCJul 20, 21:35 UTC4h 5m
2026-07-20 UAL2630 EWR → SLC Jul 20, 11:10 UTCJul 20, 15:25 UTC4h 15m
2026-07-20 UAL1317 LAS → EWR Jul 20, 01:50 UTCJul 20, 06:15 UTC4h 25m
2026-07-20 UAL1317 LAS → EWR Jul 20, 01:46 UTCJul 20, 06:07 UTC4h 21m
2026-07-19 UAL446 EWR → LAS Jul 19, 19:10 UTCJul 19, 23:45 UTC4h 35m
2026-07-19 UAL3014 - Jul 19, 14:40 UTCJul 19, 16:40 UTC2h 0m
2026-07-18 UAL734 - Jul 18, 16:15 UTCJul 18, 19:50 UTC3h 35m
2026-07-18 UAL2041 SFO → SAN Jul 18, 10:50 UTCJul 18, 12:15 UTC1h 25m
2026-07-18 UAL667 DEN → MSP Jul 18, 03:30 UTCJul 18, 05:05 UTC1h 35m
2026-07-18 UAL667 DEN → MSP Jul 18, 03:29 UTCJul 18, 05:05 UTC1h 36m
2026-07-17 UAL1368 SNA → EWR Jul 17, 21:25 UTCJul 18, 02:14 UTC4h 50m
2026-07-17 UAL1368 SNA → EWR Jul 17, 20:44 UTCJul 17, 20:55 UTC10m
2026-07-17 UAL2021 - Jul 17, 19:09 UTCJul 17, 19:30 UTC20m
2026-07-17 UAL2021 - Jul 17, 16:15 UTCJul 17, 16:59 UTC45m
2026-07-17 UAL632 ATL → IAD Jul 17, 13:40 UTCJul 17, 14:55 UTC1h 15m
2026-07-17 UAL1635 IAD → ATL Jul 17, 02:54 UTCJul 17, 04:04 UTC1h 10m
2026-07-16 UAL1223 - Jul 16, 22:45 UTCJul 16, 23:40 UTC55m
2026-07-16 UAL1629 EWR → SXM Jul 16, 14:52 UTCJul 16, 18:13 UTC3h 21m
2026-07-16 UAL1629 - Jul 16, 14:45 UTCJul 16, 15:25 UTC40m
2026-07-16 UAL2455 RSW → EWR Jul 16, 10:10 UTCJul 16, 12:40 UTC2h 30m
2026-07-16 UAL8142 - Jul 16, 02:15 UTCJul 16, 04:30 UTC2h 15m
2026-07-15 UAL1784 - Jul 15, 23:30 UTCJul 16, 00:30 UTC1h 0m
2026-07-15 UAL1784 LAS → CLE Jul 15, 17:30 UTCJul 15, 21:35 UTC4h 5m

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 N77259 page for operator, model, and routing details .

Mode-S AA739E frequently asked

What is Mode-S code AA739E?
AA739E is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N77259.
Where is Mode-S AA739E registered?
Mode-S code AA739E 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 AA739E broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 19:50 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AA739E, octal 52471636, decimal 11,170,718.
What flights does AA739E operate?
Mode-S AA739E has broadcast 20 distinct callsigns, including UAL2185, UAL1368, UAL2021, UAL1918, UAL1784.