UAL423

For travellers

Departure · Athens (ATH)

Terminal 4 · Gate A18

Scheduled 12:35 · Departed 12:58 · +23 min

Board status: Departed

Airborne since 12:57 (ADS-B)

Arrival · Chicago (ORD)

Gate INTL

Scheduled 16:00 · Estimated 15:57

Board status: Active

In the air, ~8h 22m to go (13% of the route flown)

Board data from ath, ord, updated 9 min ago; times local to each airport.

Flight

Status

In progress

Departure

Eleftherios Venizelos International Airport (ATH) — Athens, Greece

Scheduled departure

2026-10-04 09:35 UTC

Departed

2026-10-04 09:57 UTC

Arrival

Chicago O'Hare International Airport (ORD) — Chicago, United States (scheduled)

Scheduled arrival

2026-10-04 21:00 UTC

Estimated arrival

2026-10-04 20:57 UTC

Progress

13% · ~8h 22m remaining

Also flies as

UA423

Codeshares

AC4568, LH8842

Distance flown

1163 km

Straight-line distance

8770 km

Aircraft

Registration

N12021

Type

Boeing 787-10

Seats

318 total (199 Economy, 54 Economy Plus, 21 Premium Plus, 44 Polaris)

CO2 (EMEP est., total)

401.6 t (989 kg/pax Economy, 1271 kg/pax Premium Economy, 2828 kg/pax Business)

Altitude & speed

Max altitude

32,025 ft

Max ground speed

538 kt

Tracked

1h 18m · 1,163 km

Note

still in progress - the track so far

Altitude (ft, max 32,025)

Ground speed (kt, max 538)

Altitude (ft, max 32,025)

Ground speed (kt, max 538)

From the ADS-B positions we received; time since the first fix. A dashed stretch is a gap in reception, bridged by a straight line.

Route map

Airlines

Alpine Air Express (AIP)

United Airlines (UAL)

Latest flights

Departed	Flight	Route	Reg	Aircraft	Status	Distance
2026-10-04 09:57 UTC	UAL423	ATH → ORD Athens → Chicago	N12021	Boeing 787-10	In progress	~8770 km est.
2026-10-03 20:09 UTC	UAL423	ATH → ORD Athens → Chicago	N12004	Boeing 787-10	Completed	819 km
2026-10-03 10:24 UTC	UAL423	ATH → ORD Athens → Chicago	N12004	Boeing 787-10	Completed (landing confirmed by airport data)	~9177 km est. (4682 km recorded)
2026-10-02 20:21 UTC	UAL423	YSP → ORD Marathon → Chicago	N17015	Boeing 787-10	Completed	866 km
2026-10-02 11:12 UTC	UAL423	ATH → ORD Athens → Chicago	N17015	Boeing 787-10	Completed (landing confirmed by airport data)	~9222 km est. (4541 km recorded)
2026-10-01 10:16 UTC	UAL423	ATH → ORD Athens → Chicago	N91007	Boeing 787-10	Completed (landing confirmed by airport data)	9273 km
2026-09-30 10:15 UTC	UAL423	ATH → ORD Athens → Chicago	N14019	Boeing 787-10	Completed (landing confirmed by airport data)	9110 km
2026-09-29 10:00 UTC	UAL423	ATH → ORD Athens → Chicago	N13013	Boeing 787-10	Completed	9112 km
2026-09-28 10:14 UTC	UAL423	ATH → ORD Athens → Chicago	N12020	Boeing 787-10	Completed	9020 km
2026-09-27 08:29 UTC	UAL423	ATH → ORD Athens → Chicago	N16008	Boeing 787-10	Completed	8963 km
2026-09-26 20:00 UTC	UAL423	ATH → ORD Athens → Chicago	N14016	Boeing 787-10	Completed	1167 km
2026-09-26 10:51 UTC	UAL423	ATH → ORD Athens → Chicago	N14016	Boeing 787-10	Completed (landing confirmed by airport data)	~8989 km est. (4500 km recorded)
2026-09-25 19:37 UTC	UAL423	ATH → ORD Athens → Chicago	N16008	Boeing 787-10	Completed	1181 km
2026-09-25 10:08 UTC	UAL423	ATH → ORD Athens → Chicago	N16008	Boeing 787-10	Completed (landing confirmed by airport data)	~9118 km est. (4625 km recorded)
2026-09-24 09:45 UTC	UAL423	ATH → ORD Athens → Chicago	N17015	Boeing 787-10	Completed	9186 km
2026-09-23 09:51 UTC	UAL423	ATH → ORD Athens → Chicago	N14016	Boeing 787-10	Completed	9085 km
2026-09-22 19:10 UTC	UAL423	ATH → ORD Athens → Chicago	N12004	Boeing 787-10	Completed	1166 km
2026-09-22 09:52 UTC	UAL423	ATH → ORD Athens → Chicago	N12004	Boeing 787-10	Completed (landing confirmed by airport data)	~9270 km est. (3889 km recorded)
2026-09-20 10:01 UTC	UAL423	ATH → ORD Athens → Chicago	N14016	Boeing 787-10	Completed	9265 km
2026-09-19 19:32 UTC	UAL423	ATH → ORD Athens → Chicago	N16009	Boeing 787-10	Completed	892 km
2026-09-19 09:49 UTC	UAL423	ATH → ORD Athens → Chicago	N16009	Boeing 787-10	Completed (landing confirmed by airport data)	~9347 km est. (4817 km recorded)
2026-09-18 19:48 UTC	UAL423	ATH → ORD Athens → Chicago	N17015	Boeing 787-10	Completed	918 km
2026-09-18 10:30 UTC	UAL423	ATH → ORD Athens → Chicago	N17015	Boeing 787-10	Completed (landing confirmed by airport data)	~9544 km est. (3632 km recorded)
2026-09-17 19:35 UTC	UAL423	? → ORD ? → Chicago	N13018	Boeing 787-10	Completed	959 km
2026-09-17 11:33 UTC	UAL423	ATH → ? Athens → ?	N127BA	BEECHCRAFT 1900	Incomplete (signal lost)	113 km
2026-09-17 09:59 UTC	UAL423	ATH → ORD Athens → Chicago	N13018	Boeing 787-10	Completed (landing confirmed by airport data)	~9498 km est. (4629 km recorded)
2026-09-16 12:19 UTC	UAL423	ATH → ORD Athens → Chicago	N14001	Boeing 787-10	Completed	9829 km
2026-09-15 10:01 UTC	UAL423	ATH → ORD Athens → Chicago	N12020	Boeing 787-10	Completed	9688 km
2026-09-14 09:48 UTC	UAL423	ATH → ORD Athens → Chicago	N16008	Boeing 787-10	Completed	9513 km
2026-09-13 09:52 UTC	UAL423	ATH → ORD Athens → Chicago	N17015	Boeing 787-10	Completed	9516 km
2026-09-12 09:50 UTC	UAL423	ATH → ORD Athens → Chicago	N12010	Boeing 787-10	Completed	9284 km
2026-09-11 10:27 UTC	UAL423	ATH → ORD Athens → Chicago	N14011	Boeing 787-10	Completed	10167 km
2026-09-10 10:15 UTC	UAL423	ATH → ORD Athens → Chicago	N12012	Boeing 787-10	Completed	9534 km
2026-09-09 12:14 UTC	UAL423	ATH → ORD Athens → Chicago	N17002	Boeing 787-10	Completed	9347 km
2026-09-08 10:04 UTC	UAL423	ATH → ORD Athens → Chicago	N12006	Boeing 787-10	Incomplete (signal lost)	~9072 km est. (2881 km recorded)
2026-09-07 10:37 UTC	UAL423	ATH → ORD Athens → Chicago	N12021	Boeing 787-10	Completed	9357 km
2026-09-06 09:46 UTC	UAL423	ATH → ORD Athens → Chicago	N14019	Boeing 787-10	Completed	9348 km
2026-09-05 09:58 UTC	UAL423	ATH → ORD Athens → Chicago	N12005	Boeing 787-10	Completed	9405 km
2026-09-04 09:25 UTC	UAL423	ATH → ORD Athens → Chicago	N14016	Boeing 787-10	Completed	9487 km
2026-09-03 10:09 UTC	UAL423	ATH → ORD Athens → Chicago	N13014	Boeing 787-10	Completed	9544 km
2026-09-02 09:25 UTC	UAL423	ATH → ORD Athens → Chicago	N13013	Boeing 787-10	Completed	9414 km
2026-09-01 10:08 UTC	UAL423	ATH → ORD Athens → Chicago	N12021	Boeing 787-10	Completed	9306 km
2026-08-31 09:39 UTC	UAL423	ATH → ORD Athens → Chicago	N16009	Boeing 787-10	Completed	10257 km
2026-08-30 09:38 UTC	UAL423	ATH → ORD Athens → Chicago	N14016	Boeing 787-10	Completed	9171 km
2026-08-29 09:29 UTC	UAL423	ATH → ORD Athens → Chicago	N12003	Boeing 787-10	Completed	9525 km
2026-08-28 10:18 UTC	UAL423	ATH → ORD Athens → Chicago	N91007	Boeing 787-10	Completed	9404 km
2026-08-27 09:28 UTC	UAL423	ATH → ORD Athens → Chicago	N13018	Boeing 787-10	Completed	9505 km
2026-08-26 09:52 UTC	UAL423	ATH → ORD Athens → Chicago	N12012	Boeing 787-10	Completed	9592 km
2026-08-25 09:58 UTC	UAL423	ATH → ORD Athens → Chicago	N12004	Boeing 787-10	Completed	9282 km
2026-08-24 09:58 UTC	UAL423	ATH → ORD Athens → Chicago	N12020	Boeing 787-10	Completed	9524 km