Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

AAA5D4

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N78524 · BOEING 737-800 · operated by UNITED AIRLINES INC

Hex
AAA5D4
Octal
52522724
Decimal
11,183,572
Country
US
Tail
N78524
Type
B738
No current signal · last broadcast Jul 26, 23:00 UTC
Flights observed
486
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 23:00 UTC

Last known position

Most recent position reported by Mode-S AAA5D4.

Country allocation

The ICAO 24-bit address AAA5D4 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
UAL1851 - 6 2026-07-12
UAL396 United Airlines 5 2026-05-07
UAL244 United Airlines 5 2026-07-04
UAL2342 - 5 2026-07-12
UAL1896 United Airlines 5 2026-07-26
UAL1156 - 5 2026-07-13
UAL799 United Airlines 4 2026-04-23
UAL303 United Airlines 4 2026-04-25
UAL2350 United Airlines 4 2026-05-30
UAL1968 - 4 2026-07-13
UAL1881 - 4 2026-07-05
UAL1776 - 4 2026-07-16
UAL1491 - 4 2026-07-12
UAL1069 - 4 2026-07-01
UAL786 United Airlines 3 2026-06-28
UAL757 - 3 2026-06-21
UAL590 United Airlines 3 2026-04-22
UAL3901 United Airlines 3 2026-04-17
UAL334 United Airlines 3 2026-07-24
UAL2797 - 3 2026-07-03

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL1528 ORD → SFO Jul 26, 19:25 UTCJul 26, 23:00 UTC3h 35m
2026-07-26 UAL2259 LAX → EWR Jul 26, 15:50 UTCJul 26, 17:30 UTC1h 40m
2026-07-26 UAL1896 SEA → SFO Jul 26, 12:30 UTCJul 26, 14:00 UTC1h 30m
2026-07-26 UAL1896 SEA → SFO Jul 26, 12:26 UTCJul 26, 13:55 UTC1h 29m
2026-07-25 UAL1677 SFO → DFW Jul 25, 22:55 UTCJul 26, 02:45 UTC3h 50m
2026-07-25 UAL2005 DFW → SFO Jul 25, 19:25 UTCJul 25, 21:35 UTC2h 10m
2026-07-25 UAL2672 DEN → MSN Jul 25, 16:05 UTCJul 25, 17:55 UTC1h 50m
2026-07-25 UAL1355 IAD → EWR Jul 25, 13:20 UTCJul 25, 14:10 UTC50m
2026-07-24 UAL2652 SFO → BOS Jul 24, 23:00 UTCJul 24, 23:45 UTC45m
2026-07-24 UAL2199 LGA → DEN Jul 24, 18:45 UTCJul 24, 20:45 UTC2h 0m
2026-07-24 UAL669 EWR → AUS Jul 24, 15:20 UTCJul 24, 17:00 UTC1h 40m
2026-07-24 UAL669 EWR → AUS Jul 24, 15:34 UTCJul 24, 16:59 UTC1h 25m
2026-07-24 UAL2822 SFO → GUM Jul 24, 11:45 UTCJul 24, 13:40 UTC1h 55m
2026-07-24 UAL334 BOS → EWR Jul 24, 00:50 UTCJul 24, 00:55 UTC5m
2026-07-23 UAL334 BOS → EWR Jul 23, 21:35 UTCJul 24, 00:55 UTC3h 20m
2026-07-23 UAL334 BOS → EWR Jul 23, 21:36 UTCJul 24, 00:35 UTC2h 59m
2026-07-23 UAL1165 SJD → IAH Jul 23, 13:15 UTCJul 23, 19:20 UTC6h 5m
2026-07-22 UAL1911 IAD → EWR Jul 22, 22:01 UTCJul 23, 00:26 UTC2h 25m
2026-07-22 UAL1911 IAD → EWR Jul 22, 21:55 UTCJul 23, 00:30 UTC2h 35m
2026-07-22 UAL275 EWR → SFO Jul 22, 20:00 UTCJul 22, 20:15 UTC15m
2026-07-22 UAL275 EWR → SFO Jul 22, 17:50 UTCJul 22, 19:25 UTC1h 35m
2026-07-22 UAL251 - Jul 22, 14:15 UTCJul 22, 16:00 UTC1h 45m
2026-07-22 UAL1381 IAH → SAN Jul 22, 01:40 UTCJul 22, 03:20 UTC1h 40m
2026-07-21 UAL2323 ORD → MCO Jul 21, 23:05 UTCJul 21, 23:50 UTC45m
2026-07-21 UAL1022 - Jul 21, 20:05 UTCJul 21, 21:50 UTC1h 45m
2026-07-21 UAL1537 PHL → DEN Jul 21, 14:35 UTCJul 21, 18:10 UTC3h 35m
2026-07-21 UAL8130 ORD → ALB Jul 21, 00:10 UTCJul 21, 03:15 UTC3h 5m
2026-07-20 UAL302 - Jul 20, 19:45 UTCJul 20, 22:20 UTC2h 35m
2026-07-20 UAL1915 SAN → SFO Jul 20, 15:56 UTCJul 20, 18:04 UTC2h 8m
2026-07-20 UAL1915 SAN → SFO Jul 20, 15:45 UTCJul 20, 18:05 UTC2h 20m
2026-07-20 UAL2754 - Jul 20, 12:20 UTCJul 20, 14:25 UTC2h 5m
2026-07-20 UAL1371 SNA → ORD Jul 20, 02:35 UTCJul 20, 04:40 UTC2h 5m
2026-07-19 UAL1483 LAS → SFO Jul 19, 22:05 UTCJul 19, 23:50 UTC1h 45m
2026-07-19 UAL2000 LGA → IAH Jul 19, 19:50 UTCJul 19, 20:35 UTC45m
2026-07-19 UAL2306 ORD → BOS Jul 19, 14:15 UTCJul 19, 17:35 UTC3h 20m
2026-07-19 UAL2262 LAS → SFO Jul 19, 02:15 UTCJul 19, 03:30 UTC1h 15m
2026-07-18 UAL1212 SFO → SFO Jul 18, 15:55 UTCJul 18, 23:50 UTC7h 55m
2026-07-18 UAL1896 PDX → SFO Jul 18, 12:55 UTCJul 18, 14:20 UTC1h 25m
2026-07-18 UAL8151 YYZ → DTW Jul 18, 03:15 UTCJul 18, 06:50 UTC3h 35m
2026-07-17 UAL2299 DFW → ORD Jul 17, 23:20 UTCJul 18, 01:34 UTC2h 15m
2026-07-17 UAL2299 DFW → ORD Jul 17, 23:01 UTCJul 18, 01:00 UTC1h 59m
2026-07-17 UAL685 - Jul 17, 18:25 UTCJul 17, 20:10 UTC1h 45m
2026-07-17 UAL685 ORD → DFW Jul 17, 18:09 UTCJul 17, 20:04 UTC1h 55m
2026-07-17 UAL533 ORD → ORD Jul 17, 02:25 UTCJul 17, 16:40 UTC14h 15m
2026-07-16 UAL2422 - Jul 16, 21:10 UTCJul 16, 23:55 UTC2h 45m
2026-07-16 UAL2401 - Jul 16, 16:55 UTCJul 16, 19:20 UTC2h 25m
2026-07-16 UAL2401 ORD → NAS Jul 16, 16:26 UTCJul 16, 19:32 UTC3h 6m
2026-07-16 UAL1811 - Jul 16, 12:20 UTCJul 16, 14:15 UTC1h 55m
2026-07-16 UAL1776 ORD → PHL Jul 16, 00:15 UTCJul 16, 01:35 UTC1h 20m
2026-07-15 UAL2160 DFW → ORD Jul 15, 20:40 UTCJul 15, 22:35 UTC1h 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 N78524 page for operator, model, and routing details .

Mode-S AAA5D4 frequently asked

What is Mode-S code AAA5D4?
AAA5D4 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N78524.
Where is Mode-S AAA5D4 registered?
Mode-S code AAA5D4 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 AAA5D4 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 23:00 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AAA5D4, octal 52522724, decimal 11,183,572.
What flights does AAA5D4 operate?
Mode-S AAA5D4 has broadcast 20 distinct callsigns, including UAL1851, UAL396, UAL244, UAL2342, UAL1896.