UAL721

For travellers

Departure · Boston (BOS)

Terminal B · Gate B23

Scheduled 30 Sep 14:15 · Departed 30 Sep 15:30 · +75 min

Board status: Departed

Airborne since 30 Sep 15:48 (ADS-B)

Arrival · Washington, DC (IAD)

Gate D14 · Baggage belt 2

Scheduled 30 Sep 15:56 · Landed 30 Sep 17:03 · +67 min

Board status: InGate

Landed 30 Sep 17:57 (ADS-B)

Board data from bos, mwaa, updated 2018 min ago; times local to each airport.

Flight

Status

Completed

Arrival confirmed via

ADS-B (callsign change)

Departure

General Edward Lawrence Logan International Airport (BOS) — Boston, United States

Scheduled departure

2026-09-30 18:15 UTC

Departed

2026-09-30 19:48 UTC

Arrival

Washington Dulles International Airport (IAD) — Washington, DC, United States

Scheduled arrival

2026-09-30 19:56 UTC

Estimated arrival

2026-09-30 21:03 UTC

Also flies as

UA721

Codeshares

LH7451, OS7888, SN8899

Distance flown

766 km

Straight-line distance

664 km

Approach distance

92 km

Aircraft

Registration

N38446

Type

Boeing 737-900

Seats

179 total (117 Economy, 42 Economy Plus, 20 First)

CO2 (EMEP est., total)

17.2 t (91 kg/pax Economy, 131 kg/pax Business)

Altitude & speed

Max altitude

30,000 ft

Max ground speed

475 kt

Tracked

2h 9m · 762 km

Altitude (ft, max 30,000)

Ground speed (kt, max 475)

Altitude (ft, max 30,000)

Ground speed (kt, max 475)

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

Airline

United Airlines (UAL)

Latest flights

Departed	Flight	Route	Reg	Aircraft	Status	Distance
2026-10-01 18:46 UTC	UAL721	BOS → IAD Boston → Washington, DC	N75426	Boeing 737-900	Completed	777 km
2026-09-30 19:48 UTC	UAL721	BOS → IAD Boston → Washington, DC	N38446	Boeing 737-900	Completed	766 km
2026-09-29 18:21 UTC	UAL721	BOS → IAD Boston → Washington, DC	N77430	Boeing 737-900	Completed	888 km
2026-09-27 19:16 UTC	UAL721	BOS → IAD Boston → Washington, DC	N37427	Boeing 737-900	Completed	886 km
2026-09-26 18:24 UTC	UAL721	BOS → IAD Boston → Washington, DC	N813UA	Airbus A319	Completed	836 km
2026-09-25 18:21 UTC	UAL721	BOS → IAD Boston → Washington, DC	N66893	Boeing 737-900	Completed	848 km
2026-09-24 18:23 UTC	UAL721	BOS → IAD Boston → Washington, DC	N17583	Boeing 737 MAX 9	Completed	808 km
2026-09-23 18:35 UTC	UAL721	BOS → IAD Boston → Washington, DC	N68805	Boeing 737-900	Completed	832 km
2026-09-22 19:06 UTC	UAL721	BOS → IAD Boston → Washington, DC	N66825	Boeing 737-900	Completed	874 km
2026-09-22 01:26 UTC	UAL721	BOS → IAD Boston → Washington, DC	N27509	Boeing 737 MAX 9	Completed	796 km
2026-09-20 18:51 UTC	UAL721	BOS → IAD Boston → Washington, DC	N66825	Boeing 737-900	Completed	770 km
2026-09-19 18:46 UTC	UAL721	BOS → IAD Boston → Washington, DC	N77592	Boeing 737 MAX 9	Completed	853 km
2026-09-18 18:50 UTC	UAL721	BOS → IAD Boston → Washington, DC	N17413	Boeing 737 MAX 9	Completed	844 km
2026-09-17 18:45 UTC	UAL721	BOS → IAD Boston → Washington, DC	N67815	Boeing 737-900	Completed	805 km
2026-09-16 19:08 UTC	UAL721	BOS → IAD Boston → Washington, DC	N38454	Boeing 737-900	Completed	815 km
2026-09-15 18:49 UTC	UAL721	BOS → IAD Boston → Washington, DC	N36472	Boeing 737-900	Completed	830 km
2026-09-14 19:07 UTC	UAL721	BOS → IAD Boston → Washington, DC	N66841	Boeing 737-900	Completed	888 km
2026-09-13 18:57 UTC	UAL721	BOS → IAD Boston → Washington, DC	N68822	Boeing 737-900	Completed	830 km
2026-09-12 18:22 UTC	UAL721	BOS → IAD Boston → Washington, DC	N77431	Boeing 737-900	Completed	807 km
2026-09-11 18:56 UTC	UAL721	BOS → IAD Boston → Washington, DC	N68836	Boeing 737-900	Completed	848 km
2026-09-10 18:32 UTC	UAL721	BOS → IAD Boston → Washington, DC	N75436	Boeing 737-900	Completed	880 km
2026-09-09 18:57 UTC	UAL721	BOS → IAD Boston → Washington, DC	N27421	Boeing 737-900	Completed	812 km
2026-09-07 18:30 UTC	UAL721	BOS → IAD Boston → Washington, DC	N69885	Boeing 737-900	Completed	897 km
2026-09-06 18:36 UTC	UAL721	BOS → IAD Boston → Washington, DC	N28478	Boeing 737-900	Completed	826 km
2026-09-05 18:42 UTC	UAL721	BOS → IAD Boston → Washington, DC	N34455	Boeing 737-900	Completed	882 km
2026-09-04 18:24 UTC	UAL721	BOS → IAD Boston → Washington, DC	N37413	Boeing 737-900	Completed	895 km
2026-09-03 18:36 UTC	UAL721	BOS → IAD Boston → Washington, DC	N69838	Boeing 737-900	Completed	807 km
2026-09-02 22:34 UTC	UAL721	BOS → IAD Boston → Washington, DC	N61898	Boeing 737-900	Completed	847 km
2026-09-01 18:29 UTC	UAL721	BOS → IAD Boston → Washington, DC	N37474	Boeing 737-900	Completed	854 km
2026-08-31 18:32 UTC	UAL721	BOS → IAD Boston → Washington, DC	N61898	Boeing 737-900	Completed	828 km
2026-08-30 18:49 UTC	UAL721	BOS → IAD Boston → Washington, DC	N38446	Boeing 737-900	Completed	858 km
2026-08-29 18:22 UTC	UAL721	BOS → IAD Boston → Washington, DC	N34455	Boeing 737-900	Completed	852 km
2026-08-28 18:28 UTC	UAL721	BOS → IAD Boston → Washington, DC	N28478	Boeing 737-900	Completed	1044 km
2026-08-27 18:41 UTC	UAL721	BOS → IAD Boston → Washington, DC	N68452	Boeing 737-900	Completed	796 km
2026-08-26 18:37 UTC	UAL721	BOS → IAD Boston → Washington, DC	N37456	Boeing 737-900	Completed	805 km
2026-08-25 18:25 UTC	UAL721	BOS → IAD Boston → Washington, DC	N81449	Boeing 737-900	Completed	815 km
2026-08-24 18:42 UTC	UAL721	BOS → IAD Boston → Washington, DC	N78448	Boeing 737-900	Completed	921 km
2026-08-24 16:36 UTC	UAL721	? → BOS ? → Boston	N78448	Boeing 737-900	Completed	42 km
2026-08-23 18:52 UTC	UAL721	BOS → IAD Boston → Washington, DC	N37419	Boeing 737-900	Completed	847 km
2026-08-22 18:49 UTC	UAL721	BOS → IAD Boston → Washington, DC	N17414	Boeing 737 MAX 9	Completed	1324 km
2026-08-21 18:40 UTC	UAL721	BOS → IAD Boston → Washington, DC	N39423	Boeing 737-900	Completed	1130 km
2026-08-20 18:35 UTC	UAL721	BOS → IAD Boston → Washington, DC	N37437	Boeing 737-900	Completed	~2748 km est. (2040 km recorded)
2026-08-19 19:03 UTC	UAL721	BOS → IAD Boston → Washington, DC	N38467	Boeing 737-900	Completed	2457 km
2026-08-18 18:37 UTC	UAL721	BOS → IAD Boston → Washington, DC	N69835	Boeing 737-900	Completed	~2997 km est. (2185 km recorded)
2026-08-17 18:37 UTC	UAL721	BOS → IAD Boston → Washington, DC	N38454	Boeing 737-900	Completed	1702 km
2026-08-16 18:25 UTC	UAL721	BOS → IAD Boston → Washington, DC	N37462	Boeing 737-900	Completed	901 km
2026-08-14 18:36 UTC	UAL721	BOS → IAD Boston → Washington, DC	N39450	Boeing 737-900	Completed	~4273 km est. (1080 km recorded)
2026-08-12 18:41 UTC	UAL721	BOS → IAD Boston → Washington, DC	N34460	Boeing 737-900	Completed	1233 km
2026-08-11 18:37 UTC	UAL721	BOS → IAD Boston → Washington, DC	N68801	Boeing 737-900	Completed	1071 km
2026-08-10 19:53 UTC	UAL721	IAD → IAD Washington, DC → Washington, DC	N69830	Boeing 737-900	Completed	~2 km est. (0 km recorded)