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sensors Mode-S transponder

A91535

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N68452 · BOEING 737-900 · operated by UNITED AIRLINES INC

Hex
A91535
Octal
52212465
Decimal
11,081,013
Country
US
Tail
N68452
Type
B739
No current signal · last broadcast Jul 25, 16:15 UTC
Flights observed
451
Distinct callsigns
20
Country
US
Last broadcast
Jul 25, 16:15 UTC

Last known position

Most recent position reported by Mode-S A91535.

Country allocation

The ICAO 24-bit address A91535 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
UAL2443 - 8 2026-07-12
UAL2737 - 6 2026-07-05
UAL427 United Airlines 5 2026-04-22
UAL2389 - 5 2026-07-12
UAL1992 United Airlines 5 2026-06-12
UAL717 - 4 2026-06-23
UAL588 - 4 2026-07-14
UAL2736 - 4 2026-07-05
UAL2628 United Airlines 4 2026-06-15
UAL1973 United Airlines 4 2026-04-21
UAL1765 - 4 2026-06-29
UAL1623 - 4 2026-06-29
UAL1615 United Airlines 4 2026-07-21
UAL1500 - 4 2026-07-19
UAL8200 United Airlines 3 2026-04-17
UAL567 - 3 2026-07-03
UAL2865 - 3 2026-06-16
UAL2816 - 3 2026-07-20
UAL2685 - 3 2026-07-17
UAL2627 United Airlines 3 2026-07-22

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-25 UAL1252 EWR → MIA Jul 25, 14:35 UTCJul 25, 16:00 UTC1h 25m
2026-07-25 UAL1689 IAH → SFO Jul 25, 11:45 UTCJul 25, 13:05 UTC1h 20m
2026-07-23 UAL699 BWI → SFO Jul 23, 19:45 UTCJul 23, 21:15 UTC1h 30m
2026-07-23 UAL699 BWI → SFO Jul 23, 19:50 UTCJul 23, 21:37 UTC1h 47m
2026-07-23 UAL2638 EWR → RSW Jul 23, 16:00 UTCJul 23, 18:05 UTC2h 5m
2026-07-23 UAL2287 ORD → SAN Jul 23, 12:45 UTCJul 23, 13:40 UTC55m
2026-07-23 UAL1325 DEN → PDX Jul 23, 01:20 UTCJul 23, 02:10 UTC50m
2026-07-22 UAL2627 EWR → ORD Jul 22, 23:40 UTCJul 23, 00:00 UTC20m
2026-07-22 UAL2627 EWR → ORD Jul 22, 21:35 UTCJul 23, 00:00 UTC2h 25m
2026-07-22 UAL2627 EWR → ORD Jul 22, 21:07 UTCJul 22, 23:24 UTC2h 17m
2026-07-22 UAL2643 DEN → BOS Jul 22, 16:05 UTCJul 22, 19:15 UTC3h 10m
2026-07-22 UAL2446 - Jul 22, 12:10 UTCJul 22, 14:00 UTC1h 50m
2026-07-22 UAL2028 PHX → DEN Jul 22, 02:15 UTCJul 22, 04:00 UTC1h 45m
2026-07-22 UAL2028 PHX → DEN Jul 22, 02:03 UTCJul 22, 04:00 UTC1h 57m
2026-07-21 UAL1092 PHL → ORD Jul 21, 21:50 UTCJul 22, 00:45 UTC2h 55m
2026-07-21 UAL1308 EWR → ATL Jul 21, 16:20 UTCJul 21, 18:50 UTC2h 30m
2026-07-21 UAL1666 - Jul 21, 12:10 UTCJul 21, 14:35 UTC2h 25m
2026-07-21 UAL1615 CLE → SFO Jul 21, 00:15 UTCJul 21, 02:25 UTC2h 10m
2026-07-20 UAL1615 CLE → SFO Jul 20, 20:45 UTCJul 20, 22:10 UTC1h 25m
2026-07-20 UAL1686 IAH → SNA Jul 20, 18:00 UTCJul 20, 19:25 UTC1h 25m
2026-07-20 UAL2816 - Jul 20, 14:40 UTCJul 20, 16:30 UTC1h 50m
2026-07-20 UAL2816 IAH → DEN Jul 20, 14:47 UTCJul 20, 16:26 UTC1h 39m
2026-07-20 UAL2665 - Jul 20, 03:35 UTCJul 20, 05:35 UTC2h 0m
2026-07-20 UAL2665 ORD → IAH Jul 20, 03:43 UTCJul 20, 05:32 UTC1h 49m
2026-07-19 UAL2336 PDX → ORD Jul 19, 21:35 UTCJul 20, 00:32 UTC2h 57m
2026-07-19 UAL2336 - Jul 19, 21:35 UTCJul 20, 00:40 UTC3h 5m
2026-07-19 UAL644 LAX → EWR Jul 19, 17:49 UTCJul 19, 19:54 UTC2h 5m
2026-07-19 UAL644 LAX → EWR Jul 19, 17:45 UTCJul 19, 20:00 UTC2h 15m
2026-07-19 UAL1500 - Jul 19, 14:15 UTCJul 19, 15:45 UTC1h 30m
2026-07-19 UAL1500 CID → DEN Jul 19, 14:14 UTCJul 19, 15:43 UTC1h 29m
2026-07-19 UAL1923 ORD → CID Jul 19, 04:22 UTCJul 19, 04:45 UTC23m
2026-07-19 UAL2311 IAH → RNO Jul 19, 02:40 UTCJul 19, 02:45 UTC5m
2026-07-19 UAL2311 IAH → RNO Jul 19, 00:05 UTCJul 19, 02:45 UTC2h 40m
2026-07-19 UAL2311 IAH → RNO Jul 19, 00:07 UTCJul 19, 02:24 UTC2h 17m
2026-07-18 UAL1496 - Jul 18, 17:20 UTCJul 18, 21:00 UTC3h 40m
2026-07-18 UAL2816 - Jul 18, 13:45 UTCJul 18, 15:40 UTC1h 55m
2026-07-18 UAL387 - Jul 18, 02:35 UTCJul 18, 05:30 UTC2h 56m
2026-07-17 UAL1743 - Jul 17, 21:55 UTCJul 18, 00:50 UTC2h 55m
2026-07-17 UAL334 - Jul 17, 19:40 UTCJul 17, 20:15 UTC35m
2026-07-17 UAL1859 - Jul 17, 17:25 UTCJul 17, 17:50 UTC25m
2026-07-17 UAL2685 - Jul 17, 14:15 UTCJul 17, 14:50 UTC35m
2026-07-16 UAL1426 - Jul 16, 22:15 UTCJul 16, 23:05 UTC50m
2026-07-16 UAL1426 IAH → MID Jul 16, 22:20 UTCJul 17, 00:02 UTC1h 42m
2026-07-14 UAL588 DEN → IAH Jul 14, 22:41 UTCJul 15, 00:18 UTC1h 37m
2026-07-14 UAL588 - Jul 14, 22:30 UTCJul 15, 00:20 UTC1h 49m
2026-07-14 UAL1520 MCO → DEN Jul 14, 16:55 UTCJul 14, 20:20 UTC3h 25m
2026-07-14 UAL2321 DEN → MCO Jul 14, 12:10 UTCJul 14, 15:25 UTC3h 15m
2026-07-14 UAL377 ORD → DEN Jul 14, 03:40 UTCJul 14, 05:30 UTC1h 50m
2026-07-13 UAL1046 ATL → ORD Jul 13, 23:25 UTCJul 14, 01:05 UTC1h 40m
2026-07-13 UAL356 ORD → ATL Jul 13, 19:30 UTCJul 13, 20:55 UTC1h 25m

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 N68452 page for operator, model, and routing details .

Mode-S A91535 frequently asked

What is Mode-S code A91535?
A91535 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N68452.
Where is Mode-S A91535 registered?
Mode-S code A91535 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 A91535 broadcasting right now?
No active broadcast right now. Last signal was Jul 25, 16:15 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A91535, octal 52212465, decimal 11,081,013.
What flights does A91535 operate?
Mode-S A91535 has broadcast 20 distinct callsigns, including UAL2443, UAL2737, UAL427, UAL2389, UAL1992.