Apparatus

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sensors Mode-S transponder

A12778

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N17356 · operated by UNITED AIRLINES INC

Hex
A12778
Octal
50223570
Decimal
10,561,400
Country
US
Tail
N17356
Type
B38M
Broadcasting now · callsign UAL2854 · 36,575 ft
Flights observed
461
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 16:50 UTC

Current position

A12778 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A12778 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
UAL346 - 6 2026-07-07
UAL643 United Airlines 5 2026-06-10
UAL417 United Airlines 5 2026-07-26
UAL394 - 5 2026-06-26
UAL2663 - 5 2026-07-06
UAL2064 - 5 2026-07-08
UAL205 United Airlines 5 2026-04-25
UAL2039 - 5 2026-07-10
UAL1562 - 5 2026-07-15
UAL1433 United Airlines 5 2026-07-18
UAL1432 United Airlines 5 2026-07-18
UAL508 United Airlines 4 2026-05-09
UAL462 United Airlines 4 2026-04-25
UAL418 - 4 2026-07-13
UAL368 United Airlines 4 2026-04-16
UAL359 - 4 2026-07-01
UAL2448 United Airlines 4 2026-07-19
UAL2318 United Airlines 4 2026-07-22
UAL1903 United Airlines 4 2026-05-13
UAL1901 United Airlines 4 2026-07-24

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL417 LAX → OGG Jul 26, 16:20 UTCJul 26, 16:50 UTC30m
2026-07-25 UAL605 SFO → PDX Jul 25, 22:25 UTCJul 26, 03:50 UTC5h 25m
2026-07-25 UAL2035 LAX → SFO Jul 25, 15:35 UTCJul 25, 20:25 UTC4h 50m
2026-07-25 UAL1612 IAH → BOS Jul 25, 08:25 UTCJul 25, 08:35 UTC10m
2026-07-25 UAL1612 IAH → BOS Jul 25, 08:13 UTCJul 25, 13:08 UTC4h 55m
2026-07-25 UAL1104 SJC → DEN Jul 25, 00:40 UTCJul 25, 05:55 UTC5h 15m
2026-07-24 UAL2184 MCO → EWR Jul 24, 21:50 UTCJul 24, 22:30 UTC40m
2026-07-24 UAL1524 IAH → EWR Jul 24, 17:25 UTCJul 24, 20:05 UTC2h 40m
2026-07-24 UAL1901 GUA → IAH Jul 24, 14:20 UTCJul 24, 14:55 UTC35m
2026-07-24 UAL1901 GUA → IAH Jul 24, 12:35 UTCJul 24, 12:45 UTC10m
2026-07-24 UAL1137 LAX → GUA Jul 24, 06:40 UTCJul 24, 11:00 UTC4h 20m
2026-07-23 UAL1296 EWR → TPA Jul 23, 23:10 UTCJul 24, 04:00 UTC4h 50m
2026-07-23 UAL1295 LAX → LIH Jul 23, 16:05 UTCJul 23, 21:15 UTC5h 10m
2026-07-23 UAL2096 - Jul 23, 13:10 UTCJul 23, 14:10 UTC1h 0m
2026-07-23 UAL1898 - Jul 23, 02:35 UTCJul 23, 03:25 UTC50m
2026-07-22 UAL387 YVR → LAX Jul 22, 22:10 UTCJul 23, 00:40 UTC2h 30m
2026-07-22 UAL2318 DEN → LAX Jul 22, 18:10 UTCJul 22, 20:30 UTC2h 20m
2026-07-22 UAL2318 DEN → LAX Jul 22, 18:07 UTCJul 22, 20:34 UTC2h 27m
2026-07-22 UAL776 ORD → SJC Jul 22, 11:30 UTCJul 22, 15:50 UTC4h 20m
2026-07-22 UAL776 ORD → SJC Jul 22, 11:28 UTCJul 22, 15:41 UTC4h 13m
2026-07-21 UAL2476 DEN → CLE Jul 21, 20:10 UTCJul 21, 22:25 UTC2h 15m
2026-07-21 UAL779 BOS → IAH Jul 21, 16:35 UTCJul 21, 18:15 UTC1h 40m
2026-07-21 UAL1336 SNA → IAH Jul 21, 12:20 UTCJul 21, 14:25 UTC2h 5m
2026-07-21 UAL1336 SNA → IAH Jul 21, 12:33 UTCJul 21, 14:28 UTC1h 55m
2026-07-21 UAL450 SFO → MIA Jul 21, 09:45 UTCJul 21, 09:50 UTC5m
2026-07-21 UAL450 SFO → MIA Jul 21, 04:18 UTCJul 21, 09:30 UTC5h 12m
2026-07-21 UAL450 SFO → MIA Jul 21, 04:10 UTCJul 21, 05:05 UTC55m
2026-07-20 UAL2369 MSY → IAH Jul 20, 19:45 UTCJul 21, 02:10 UTC6h 24m
2026-07-20 UAL2369 MSY → IAH Jul 20, 19:40 UTCJul 21, 02:09 UTC6h 29m
2026-07-20 UAL2421 - Jul 20, 16:35 UTCJul 20, 18:05 UTC1h 30m
2026-07-20 UAL2421 - Jul 20, 16:05 UTCJul 20, 16:30 UTC25m
2026-07-20 UAL1353 IAD → EWR Jul 20, 12:45 UTCJul 20, 14:50 UTC2h 5m
2026-07-20 UAL1353 IAD → EWR Jul 20, 12:44 UTCJul 20, 14:43 UTC1h 59m
2026-07-20 UAL2083 UIO → IAH Jul 20, 05:49 UTCJul 20, 10:20 UTC4h 31m
2026-07-19 UAL2083 UIO → IAH Jul 19, 23:35 UTCJul 20, 10:25 UTC10h 50m
2026-07-19 UAL1589 IAH → LGA Jul 19, 17:30 UTCJul 19, 20:40 UTC3h 10m
2026-07-19 UAL2448 PHX → SFO Jul 19, 12:55 UTCJul 19, 16:05 UTC3h 10m
2026-07-19 UAL2448 PHX → SFO Jul 19, 12:47 UTCJul 19, 16:04 UTC3h 17m
2026-07-19 UAL1097 - Jul 19, 06:40 UTCJul 19, 08:00 UTC1h 20m
2026-07-19 UAL1097 SJO → IAH Jul 19, 06:43 UTCJul 19, 09:49 UTC3h 6m
2026-07-19 UAL1055 - Jul 19, 01:15 UTCJul 19, 04:20 UTC3h 5m
2026-07-18 UAL1433 EWR → YVR Jul 18, 19:50 UTCJul 18, 22:10 UTC2h 20m
2026-07-18 UAL1432 IAH → MGA Jul 18, 15:20 UTCJul 18, 15:45 UTC25m
2026-07-18 UAL1432 IAH → MGA Jul 18, 15:15 UTCJul 18, 18:05 UTC2h 50m
2026-07-18 UAL2074 IAD → DEN Jul 18, 10:40 UTCJul 18, 12:55 UTC2h 15m
2026-07-17 UAL2498 - Jul 17, 23:20 UTCJul 18, 01:39 UTC2h 20m
2026-07-17 UAL1589 - Jul 17, 17:25 UTCJul 17, 20:35 UTC3h 10m
2026-07-17 UAL2448 - Jul 17, 12:45 UTCJul 17, 15:49 UTC3h 5m
2026-07-17 UAL2083 - Jul 17, 07:20 UTCJul 17, 10:25 UTC3h 5m
2026-07-16 UAL1002 DEN → SJC Jul 16, 23:40 UTCJul 17, 02:50 UTC3h 10m

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 N17356 page for operator, model, and routing details .

Mode-S A12778 frequently asked

What is Mode-S code A12778?
A12778 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N17356.
Where is Mode-S A12778 registered?
Mode-S code A12778 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 A12778 broadcasting right now?
Yes. Mode-S A12778 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A12778, octal 50223570, decimal 10,561,400.
What flights does A12778 operate?
Mode-S A12778 has broadcast 20 distinct callsigns, including UAL346, UAL643, UAL417, UAL394, UAL2663.