| Date | From | To | Departure | Arrival | Status | |
|---|---|---|---|---|---|---|
| Aug 15 | LHR | SEA | 18:11 | 19:22 |
En-Route
|
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| Aug 14 | LHR | SEA | 19:37 | 20:52 |
Delayed
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| Aug 13 | LHR | SEA | 18:03 | 19:21 |
Landed
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| Aug 12 | LHR | SEA | 18:03 | 19:12 |
Landed
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| Aug 11 | LHR | SEA | 18:10 | 19:24 |
Landed
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| Aug 10 | LHR | SEA | 17:54 | 19:15 |
Landed
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| Aug 09 | LHR | SEA | 18:57 | 20:17 |
Landed
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| Aug 08 | LHR | SEA | 17:57 | 19:23 |
Landed
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| Aug 07 | LHR | SEA | 18:28 | 19:47 |
Landed
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| Aug 06 | LHR | SEA | 19:05 | 20:35 |
Landed Late
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Delta Air Lines Flight DL21 connects London, United Kingdom to Seattle, United States, taking off from London Heathrow Airport LHR and landing at Seattle Tacoma International Airport SEA.
How long is the DL21 flight from London to Seattle?
The average flight time from London to Seattle is 9 hours and 18 minutes. The flight distance is 7701 km / 4785 miles and the average flight speed is 828 km/h / 514 mph.
How many DL21 flights are operated per week?
6 flights per week. The flight DL21 is operated on Monday, Tuesday, Wednesday, Thursday, Friday and Saturday.
What is the On-Time Performance (OTP) of Delta Air Lines Flight DL21 London to Seattle?
The Airportia On-Time Performance Rating for Delta Air Lines Flight DL21 is 4.9/5 stars. This metric is calculated using data from the past 10 flights.
When was the latest DL21 flight?
The latest flight took off on Sunday, August 16th, 2026 with the flight status being En-Route on 19:22.
How else can the flight DL21 be referenced as?
This Delta Air Lines flight can also be referenced as DAL21, DAL021, DL021, DL0021, DL 21, DAL 21.
How often is flight DL21 delayed?
On average, 20% of all DL21 flights are delayed. The average delay is 40 minutes.
Can I get compensation for my delayed or cancelled DL21 flight or baggage issues?
If your DL21 flight was cancelled, delayed, or if you experienced baggage issues such as delayed, damaged, or lost bags, you may be entitled to compensation. Compensation amounts and eligibility depend on various regulations, including EC 261/2004, UK261, CA Montreal Convention, US GoodWill, BR-ANAC, SA-GACA and TK-SHY.
See our DL21 Flight Tracker above for more details.
Flight DL21 is code-shared by 5 airlines using the flight numbers VS4036, AF3586, KL6022, SK3985, SV4416
Other flights departing from London LHR: KC664, RJ5212, LH2479, VS147
Other flights arriving at Seattle SEA: AS3, AS31, AS419, Y41850
All flights connecting London LHR to Seattle SEA.
