Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A8D5A4

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N66897 · BOEING 737-900 · operated by UNITED AIRLINES INC

Hex
A8D5A4
Octal
52152644
Decimal
11,064,740
Country
US
Tail
N66897
Type
B739
No current signal · last broadcast Jul 26, 22:45 UTC
Flights observed
463
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:45 UTC

Last known position

Most recent position reported by Mode-S A8D5A4.

Country allocation

The ICAO 24-bit address A8D5A4 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
UAL1834 United Airlines 8 2026-07-24
UAL1010 - 7 2026-07-05
UAL2209 - 6 2026-07-06
UAL1598 United Airlines 6 2026-05-20
UAL1308 - 6 2026-07-11
UAL577 - 5 2026-06-28
UAL1373 - 5 2026-07-09
UAL721 - 4 2026-07-15
UAL533 United Airlines 4 2026-04-17
UAL2677 United Airlines 4 2026-05-08
UAL2648 United Airlines 4 2026-06-15
UAL2402 United Airlines 4 2026-05-19
UAL2322 - 4 2026-07-04
UAL2183 United Airlines 4 2026-05-08
UAL1168 United Airlines 4 2026-06-09
UAL1154 - 4 2026-07-08
UAL644 United Airlines 3 2026-06-03
UAL3905 United Airlines 3 2026-05-25
UAL2858 - 3 2026-07-12
UAL2631 United Airlines 3 2026-05-13

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 UAL382 IAH → SAT Jul 26, 21:40 UTCJul 26, 22:45 UTC1h 5m
2026-07-26 UAL2498 IAH → EWR Jul 26, 16:20 UTCJul 26, 19:50 UTC3h 30m
2026-07-26 UAL500 IND → SFO Jul 26, 10:25 UTCJul 26, 14:40 UTC4h 15m
2026-07-26 UAL500 IND → SFO Jul 26, 10:28 UTCJul 26, 14:36 UTC4h 8m
2026-07-26 UAL1199 EWR → CLT Jul 26, 00:15 UTCJul 26, 02:15 UTC2h 0m
2026-07-25 UAL302 DFW → EWR Jul 25, 19:55 UTCJul 25, 22:20 UTC2h 25m
2026-07-25 UAL302 DFW → EWR Jul 25, 19:57 UTCJul 25, 22:19 UTC2h 22m
2026-07-25 UAL1915 SAN → SFO Jul 25, 15:50 UTCJul 25, 18:05 UTC2h 15m
2026-07-25 UAL1188 RDM → DEN Jul 25, 12:20 UTCJul 25, 14:20 UTC2h 0m
2026-07-25 UAL1588 EWR → SAV Jul 25, 02:50 UTCJul 25, 04:45 UTC1h 55m
2026-07-24 UAL1773 MIA → EWR Jul 24, 21:45 UTCJul 25, 01:10 UTC3h 25m
2026-07-24 UAL1834 DFW → EWR Jul 24, 17:10 UTCJul 24, 19:10 UTC2h 0m
2026-07-24 UAL1834 DFW → EWR Jul 24, 16:48 UTCJul 24, 19:17 UTC2h 29m
2026-07-24 UAL1834 DFW → EWR Jul 24, 13:15 UTCJul 24, 15:00 UTC1h 45m
2026-07-24 UAL1834 DFW → EWR Jul 24, 12:55 UTCJul 24, 13:10 UTC15m
2026-07-24 UAL1834 DFW → EWR Jul 24, 12:29 UTCJul 24, 15:08 UTC2h 39m
2026-07-24 UAL2058 IAD → IAH Jul 24, 00:45 UTCJul 24, 01:35 UTC50m
2026-07-23 UAL1800 SNA → IAH Jul 23, 20:10 UTCJul 23, 22:40 UTC2h 30m
2026-07-23 UAL677 ORD → BOS Jul 23, 18:10 UTCJul 23, 18:50 UTC40m
2026-07-23 UAL677 ORD → BOS Jul 23, 16:05 UTCJul 23, 18:05 UTC2h 0m
2026-07-23 UAL1969 EWR → IAH Jul 23, 11:45 UTCJul 23, 14:00 UTC2h 15m
2026-07-23 UAL1399 LAX → SFO Jul 23, 03:00 UTCJul 23, 05:45 UTC2h 45m
2026-07-22 UAL1051 CUN → EWR Jul 22, 18:50 UTCJul 22, 22:05 UTC3h 15m
2026-07-22 UAL1018 SJC → IAH Jul 22, 15:00 UTCJul 22, 16:55 UTC1h 55m
2026-07-21 UAL1916 IAH → PTY Jul 21, 15:19 UTCJul 21, 19:03 UTC3h 44m
2026-07-21 UAL1033 PTY → IAH Jul 21, 15:25 UTCJul 22, 00:20 UTC8h 55m
2026-07-21 UAL2773 HNL → ORD Jul 21, 11:20 UTCJul 21, 13:25 UTC2h 5m
2026-07-20 UAL2778 HKG → SFO Jul 20, 23:55 UTCJul 21, 02:10 UTC2h 15m
2026-07-20 UAL2778 HKG → SFO Jul 20, 23:54 UTCJul 21, 02:08 UTC2h 14m
2026-07-20 UAL1545 SFO → LAX Jul 20, 19:20 UTCJul 20, 21:35 UTC2h 15m
2026-07-20 UAL1545 SFO → LAX Jul 20, 19:21 UTCJul 20, 21:33 UTC2h 12m
2026-07-20 UAL486 - Jul 20, 15:35 UTCJul 20, 17:45 UTC2h 10m
2026-07-19 UAL1213 EWR → ATL Jul 19, 20:15 UTCJul 19, 22:35 UTC2h 20m
2026-07-19 UAL2120 MFE → IAH Jul 19, 15:05 UTCJul 19, 17:00 UTC1h 55m
2026-07-18 UAL1932 - Jul 18, 00:10 UTCJul 18, 02:09 UTC2h 0m
2026-07-17 UAL1932 EWR → MCO Jul 17, 23:53 UTCJul 18, 02:08 UTC2h 15m
2026-07-17 UAL2489 SDQ → EWR Jul 17, 17:27 UTCJul 17, 20:56 UTC3h 29m
2026-07-17 UAL2489 EWR → EWR Jul 17, 12:04 UTCJul 17, 21:00 UTC8h 55m
2026-07-16 UAL485 - Jul 16, 22:35 UTCJul 17, 00:14 UTC1h 40m
2026-07-16 UAL485 ORD → EWR Jul 16, 22:04 UTCJul 17, 00:18 UTC2h 14m
2026-07-16 UAL2331 IAD → ORD Jul 16, 17:36 UTCJul 16, 18:46 UTC1h 10m
2026-07-16 UAL2331 IAD → ORD Jul 16, 17:30 UTCJul 16, 19:10 UTC1h 40m
2026-07-16 UAL1893 MCO → IAD Jul 16, 13:45 UTCJul 16, 15:25 UTC1h 40m
2026-07-15 UAL2463 IAD → MCO Jul 15, 21:50 UTCJul 15, 23:35 UTC1h 45m
2026-07-15 UAL721 BOS → IAD Jul 15, 18:25 UTCJul 15, 19:40 UTC1h 15m
2026-07-15 UAL1117 PWK → BOS Jul 15, 14:40 UTCJul 15, 16:30 UTC1h 50m
2026-07-15 UAL546 - Jul 15, 00:45 UTCJul 15, 02:30 UTC1h 45m
2026-07-15 UAL546 - Jul 15, 00:35 UTCJul 15, 00:40 UTC5m
2026-07-14 UAL1647 BOS → EWR Jul 14, 22:15 UTCJul 14, 23:05 UTC49m
2026-07-14 UAL1536 EWR → BOS Jul 14, 19:35 UTCJul 14, 20:25 UTC50m

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 N66897 page for operator, model, and routing details .

Mode-S A8D5A4 frequently asked

What is Mode-S code A8D5A4?
A8D5A4 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N66897.
Where is Mode-S A8D5A4 registered?
Mode-S code A8D5A4 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 A8D5A4 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 22:45 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A8D5A4, octal 52152644, decimal 11,064,740.
What flights does A8D5A4 operate?
Mode-S A8D5A4 has broadcast 20 distinct callsigns, including UAL1834, UAL1010, UAL2209, UAL1598, UAL1308.