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sensors Mode-S transponder

AA6E81

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N771UA · BOEING 777-200 · operated by UNITED AIRLINES INC

Hex
AA6E81
Octal
52467201
Decimal
11,169,409
Country
US
Tail
N771UA
Type
B772
No current signal · last broadcast Jul 26, 22:00 UTC
Flights observed
240
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:00 UTC

Last known position

Most recent position reported by Mode-S AA6E81.

Country allocation

The ICAO 24-bit address AA6E81 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
UAL384 United Airlines 24 2026-07-23
UAL1805 United Airlines 24 2026-07-21
UAL383 United Airlines 20 2026-07-20
UAL1806 United Airlines 18 2026-07-22
UAL300 United Airlines 13 2026-07-19
UAL252 United Airlines 13 2026-07-24
UAL1736 - 13 2026-07-20
UAL253 United Airlines 12 2026-07-24
UAL1735 United Airlines 10 2026-07-21
UAL1157 United Airlines 10 2026-07-26
UAL1170 - 9 2026-07-17
UAL604 United Airlines 7 2026-07-18
UAL2358 United Airlines 7 2026-07-18
UAL2475 - 6 2026-06-21
UAL1169 United Airlines 6 2026-07-25
UAL1158 United Airlines 6 2026-07-26
UAL373 United Airlines 5 2026-04-19
UAL2280 United Airlines 4 2026-06-21
UAL368 - 3 2026-06-21
UAL1818 - 3 2026-07-17

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL1158 LAX → HNL Jul 26, 21:40 UTCJul 26, 22:00 UTC20m
2026-07-26 UAL1158 LAX → HNL Jul 26, 17:00 UTCJul 26, 17:30 UTC30m
2026-07-26 UAL1157 BOS → IAD Jul 26, 03:55 UTCJul 26, 04:40 UTC45m
2026-07-26 UAL1157 BOS → IAD Jul 26, 00:10 UTCJul 26, 03:40 UTC3h 30m
2026-07-25 UAL1158 LAX → HNL Jul 25, 16:55 UTCJul 25, 22:05 UTC5h 10m
2026-07-25 UAL1169 BDL → ORD Jul 25, 08:15 UTCJul 25, 12:55 UTC4h 40m
2026-07-24 UAL253 IAH → HNL Jul 24, 15:45 UTCJul 24, 23:25 UTC7h 40m
2026-07-24 UAL252 HNL → IAH Jul 24, 06:30 UTCJul 24, 06:45 UTC15m
2026-07-24 UAL252 HNL → IAH Jul 24, 06:08 UTCJul 24, 13:27 UTC7h 19m
2026-07-23 UAL384 DEN → HNL Jul 23, 18:20 UTCJul 24, 01:10 UTC6h 50m
2026-07-22 UAL1806 MCI → EWR Jul 22, 11:25 UTCJul 22, 13:45 UTC2h 20m
2026-07-21 UAL1805 LAS → EWR Jul 21, 22:55 UTCJul 22, 00:55 UTC2h 0m
2026-07-21 UAL1805 LAS → EWR Jul 21, 22:48 UTCJul 22, 05:32 UTC6h 44m
2026-07-21 UAL1735 LAS → EWR Jul 21, 09:40 UTCJul 21, 12:10 UTC2h 30m
2026-07-20 UAL1736 - Jul 20, 18:40 UTCJul 20, 21:05 UTC2h 25m
2026-07-20 UAL383 HNL → DEN Jul 20, 09:55 UTCJul 20, 12:05 UTC2h 10m
2026-07-20 UAL383 HNL → DEN Jul 20, 05:55 UTCJul 20, 06:05 UTC10m
2026-07-20 UAL384 - Jul 20, 01:00 UTCJul 20, 01:10 UTC10m
2026-07-19 UAL384 - Jul 19, 18:25 UTCJul 19, 20:40 UTC2h 15m
2026-07-19 UAL383 HNL → DEN Jul 19, 06:15 UTCJul 19, 12:05 UTC5h 50m
2026-07-19 UAL383 HNL → DEN Jul 19, 06:08 UTCJul 19, 12:01 UTC5h 53m
2026-07-19 UAL300 SFO → HNL Jul 19, 01:50 UTCJul 19, 02:10 UTC20m
2026-07-18 UAL300 SFO → HNL Jul 18, 21:22 UTCJul 19, 02:08 UTC4h 46m
2026-07-18 UAL300 SFO → HNL Jul 18, 21:15 UTCJul 18, 21:50 UTC35m
2026-07-18 UAL2358 SAN → EWR Jul 18, 15:15 UTCJul 18, 18:25 UTC3h 10m
2026-07-18 UAL604 DEN → SYR Jul 18, 08:10 UTCJul 18, 11:20 UTC3h 10m
2026-07-17 UAL1818 - Jul 17, 23:50 UTCJul 18, 00:04 UTC15m
2026-07-17 UAL1818 HNL → SFO Jul 17, 23:45 UTCJul 18, 04:04 UTC4h 19m
2026-07-17 UAL1158 LAX → HNL Jul 17, 16:34 UTCJul 17, 21:44 UTC5h 10m
2026-07-17 UAL1158 LAX → HNL Jul 17, 16:21 UTCJul 17, 21:45 UTC5h 24m
2026-07-17 UAL1169 - Jul 17, 07:55 UTCJul 17, 08:15 UTC20m
2026-07-17 UAL1169 HNL → LAX Jul 17, 07:59 UTCJul 17, 12:30 UTC4h 31m
2026-07-17 UAL1170 - Jul 17, 00:20 UTCJul 17, 05:35 UTC5h 15m
2026-07-15 UAL1157 - Jul 15, 23:30 UTCJul 16, 04:15 UTC4h 45m
2026-07-15 UAL384 - Jul 15, 00:45 UTCJul 15, 01:05 UTC20m
2026-07-14 UAL384 - Jul 14, 18:25 UTCJul 14, 20:45 UTC2h 20m
2026-07-14 UAL1806 - Jul 14, 08:00 UTCJul 14, 14:10 UTC6h 10m
2026-07-13 UAL253 - Jul 13, 18:25 UTCJul 14, 01:45 UTC7h 20m
2026-07-13 UAL253 IAH → HNL Jul 13, 18:22 UTCJul 14, 01:45 UTC7h 23m
2026-07-13 UAL252 - Jul 13, 10:15 UTCJul 13, 13:30 UTC3h 15m
2026-07-13 UAL252 - Jul 13, 06:05 UTCJul 13, 06:25 UTC20m
2026-07-13 UAL300 - Jul 13, 01:30 UTCJul 13, 01:55 UTC25m
2026-07-12 UAL300 SFO → HNL Jul 12, 21:22 UTCJul 13, 01:57 UTC4h 35m
2026-07-12 UAL300 - Jul 12, 21:10 UTCJul 12, 21:45 UTC35m
2026-07-12 UAL1147 - Jul 12, 12:50 UTCJul 12, 17:30 UTC4h 40m
2026-07-11 UAL1791 SFO → IAD Jul 11, 20:40 UTCJul 12, 01:05 UTC4h 25m
2026-07-11 UAL1147 - Jul 11, 12:50 UTCJul 11, 18:00 UTC5h 10m
2026-07-11 UAL1147 IAD → SFO Jul 11, 12:55 UTCJul 11, 17:49 UTC4h 54m
2026-07-10 UAL8191 SFO → IAD Jul 10, 21:00 UTCJul 11, 01:20 UTC4h 20m
2026-07-10 UAL2610 - Jul 10, 14:40 UTCJul 10, 18:35 UTC3h 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 N771UA page for operator, model, and routing details .

Mode-S AA6E81 frequently asked

What is Mode-S code AA6E81?
AA6E81 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N771UA.
Where is Mode-S AA6E81 registered?
Mode-S code AA6E81 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 AA6E81 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 22:00 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AA6E81, octal 52467201, decimal 11,169,409.
What flights does AA6E81 operate?
Mode-S AA6E81 has broadcast 20 distinct callsigns, including UAL384, UAL1805, UAL383, UAL1806, UAL300.