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sensors Mode-S transponder

AA7E99

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N77542 · BOEING 737-800 · operated by UNITED AIRLINES INC

Hex
AA7E99
Octal
52477231
Decimal
11,173,529
Country
US
Tail
N77542
Type
B738
No current signal · last broadcast Jul 24, 01:45 UTC
Flights observed
465
Distinct callsigns
20
Country
US
Last broadcast
Jul 24, 01:45 UTC

Last known position

Most recent position reported by Mode-S AA7E99.

Country allocation

The ICAO 24-bit address AA7E99 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
UAL362 United Airlines 4 2026-07-23
UAL2285 United Airlines 4 2026-05-12
UAL1609 United Airlines 4 2026-04-17
UAL1360 - 4 2026-07-03
UAL645 United Airlines 3 2026-06-11
UAL640 - 3 2026-07-10
UAL586 United Airlines 3 2026-06-09
UAL453 United Airlines 3 2026-06-08
UAL2786 - 3 2026-07-11
UAL2484 - 3 2026-04-16
UAL2457 United Airlines 3 2026-06-10
UAL2430 - 3 2026-06-29
UAL2375 - 3 2026-07-15
UAL2342 - 3 2026-07-22
UAL2270 - 3 2026-06-25
UAL2234 United Airlines 3 2026-05-16
UAL2167 - 3 2026-04-13
UAL216 United Airlines 3 2026-04-26
UAL2043 United Airlines 3 2026-06-10
UAL1931 - 3 2026-07-11

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-23 UAL8141 SAN → EWR Jul 23, 22:15 UTCJul 24, 01:45 UTC3h 30m
2026-07-23 UAL8141 SAN → EWR Jul 23, 22:12 UTCJul 24, 01:47 UTC3h 35m
2026-07-23 UAL2470 DEN → MCI Jul 23, 18:30 UTCJul 23, 20:45 UTC2h 15m
2026-07-23 UAL362 HNL → EWR Jul 23, 14:40 UTCJul 23, 16:15 UTC1h 35m
2026-07-23 UAL362 HNL → EWR Jul 23, 14:09 UTCJul 23, 17:04 UTC2h 55m
2026-07-23 UAL362 HNL → EWR Jul 23, 10:20 UTCJul 23, 12:15 UTC1h 55m
2026-07-23 UAL2144 IAH → SFO Jul 23, 01:20 UTCJul 23, 02:05 UTC45m
2026-07-22 UAL312 DSM → ORD Jul 22, 20:10 UTCJul 22, 23:05 UTC2h 55m
2026-07-22 UAL2342 - Jul 22, 16:20 UTCJul 22, 18:45 UTC2h 25m
2026-07-22 UAL2822 - Jul 22, 11:40 UTCJul 22, 13:35 UTC1h 55m
2026-07-22 UAL2857 IAH → SAT Jul 22, 02:45 UTCJul 22, 05:25 UTC2h 40m
2026-07-22 UAL2857 IAH → SAT Jul 22, 02:51 UTCJul 22, 05:46 UTC2h 55m
2026-07-21 UAL2263 EWR → FLL Jul 21, 15:05 UTCJul 21, 20:35 UTC5h 30m
2026-07-21 UAL2323 ORD → MCO Jul 21, 04:20 UTCJul 21, 04:55 UTC35m
2026-07-21 UAL1022 DEN → SAT Jul 21, 01:35 UTCJul 21, 03:15 UTC1h 40m
2026-07-20 UAL1788 - Jul 20, 20:20 UTCJul 20, 21:00 UTC40m
2026-07-20 UAL1788 GJT → DEN Jul 20, 19:52 UTCJul 20, 20:56 UTC1h 4m
2026-07-20 UAL1714 LAS → IAH Jul 20, 17:50 UTCJul 20, 18:05 UTC15m
2026-07-20 UAL1424 OKC → DEN Jul 20, 14:45 UTCJul 20, 15:55 UTC1h 10m
2026-07-20 UAL1184 IAH → MSY Jul 20, 00:00 UTCJul 20, 01:10 UTC1h 10m
2026-07-19 UAL479 CVG → DEN Jul 19, 20:20 UTCJul 19, 22:35 UTC2h 15m
2026-07-19 UAL1978 - Jul 19, 16:45 UTCJul 19, 19:00 UTC2h 15m
2026-07-19 UAL2865 SBA → DEN Jul 19, 12:15 UTCJul 19, 14:15 UTC2h 0m
2026-07-19 UAL2479 - Jul 19, 03:05 UTCJul 19, 05:00 UTC1h 55m
2026-07-18 UAL1390 ORF → DEN Jul 18, 21:10 UTCJul 19, 00:40 UTC3h 30m
2026-07-18 UAL2011 EWR → SNA Jul 18, 15:55 UTCJul 18, 19:25 UTC3h 30m
2026-07-18 UAL550 YYC → DEN Jul 18, 12:30 UTCJul 18, 14:20 UTC1h 50m
2026-07-18 UAL720 - Jul 18, 01:30 UTCJul 18, 03:40 UTC2h 11m
2026-07-17 UAL486 - Jul 17, 20:44 UTCJul 17, 23:25 UTC2h 40m
2026-07-17 UAL464 RSW → CLE Jul 17, 17:15 UTCJul 17, 19:25 UTC2h 10m
2026-07-17 UAL1100 - Jul 17, 13:20 UTCJul 17, 14:15 UTC55m
2026-07-17 UAL1100 CLE → RSW Jul 17, 13:29 UTCJul 17, 15:35 UTC2h 6m
2026-07-17 UAL8197 - Jul 17, 07:00 UTCJul 17, 11:15 UTC4h 15m
2026-07-17 UAL8197 SFO → CLE Jul 17, 07:03 UTCJul 17, 11:08 UTC4h 5m
2026-07-17 UAL2278 - Jul 17, 04:39 UTCJul 17, 05:45 UTC1h 5m
2026-07-17 UAL1561 - Jul 17, 01:05 UTCJul 17, 02:25 UTC1h 20m
2026-07-17 UAL1561 SFO → SAN Jul 17, 00:49 UTCJul 17, 02:18 UTC1h 29m
2026-07-16 UAL2077 - Jul 16, 22:19 UTCJul 16, 23:35 UTC1h 15m
2026-07-16 UAL318 DEN → EUG Jul 16, 17:40 UTCJul 16, 20:09 UTC2h 30m
2026-07-16 UAL1891 MSP → DEN Jul 16, 14:25 UTCJul 16, 16:00 UTC1h 35m
2026-07-16 UAL667 DEN → MSP Jul 16, 03:10 UTCJul 16, 04:40 UTC1h 30m
2026-07-15 UAL1787 - Jul 15, 23:45 UTCJul 16, 02:00 UTC2h 15m
2026-07-15 UAL2455 DEN → PDX Jul 15, 19:46 UTCJul 15, 21:54 UTC2h 8m
2026-07-15 UAL2455 DEN → PDX Jul 15, 19:45 UTCJul 15, 21:55 UTC2h 10m
2026-07-15 UAL2375 PDX → DEN Jul 15, 16:05 UTCJul 15, 18:15 UTC2h 10m
2026-07-15 UAL2375 PDX → DEN Jul 15, 16:01 UTCJul 15, 18:10 UTC2h 9m
2026-07-14 UAL1677 ORD → PDX Jul 14, 22:20 UTCJul 15, 01:50 UTC3h 29m
2026-07-14 UAL1677 ORD → PDX Jul 14, 21:48 UTCJul 15, 01:44 UTC3h 56m
2026-07-14 UAL2331 IAD → ORD Jul 14, 17:40 UTCJul 14, 19:00 UTC1h 20m
2026-07-14 UAL525 AUS → IAD Jul 14, 13:00 UTCJul 14, 16:00 UTC3h 0m

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 N77542 page for operator, model, and routing details .

Mode-S AA7E99 frequently asked

What is Mode-S code AA7E99?
AA7E99 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N77542.
Where is Mode-S AA7E99 registered?
Mode-S code AA7E99 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 AA7E99 broadcasting right now?
No active broadcast right now. Last signal was Jul 24, 01:45 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AA7E99, octal 52477231, decimal 11,173,529.
What flights does AA7E99 operate?
Mode-S AA7E99 has broadcast 20 distinct callsigns, including UAL362, UAL2285, UAL1609, UAL1360, UAL645.