logo

DL20 Flight Information & Schedule

Delta Air Lines · Seattle–Tacoma International Airport (SEA) to London Heathrow Airport (LHR)

Enter a flight number and departure date to find the flight page
DL20 Seattle–Tacoma International Airport to London Heathrow Airport nonstop flight: schedule, airports, aircraft and travel guide.

DL20 Flight Overview

DL20 is operated by Delta Air Lines and connects Seattle–Tacoma International Airport (SEA) and London Heathrow Airport (LHR). Scheduled departure: 2026-10-29 17:45 (UTC-07:00); scheduled arrival: 2026-10-30 10:40 (UTC+00:00).

AirlineDelta Air Lines
Flight numberDL20
RouteSEA to LHR
Scheduled duration9 hr 55 min

Seattle to London Route Information

DL20 is a nonstop international flight from Seattle–Tacoma International Airport (SEA) to London Heathrow Airport (LHR). Use the information below to plan your journey.

Route distanceApprox. 7,725 km
Scheduled flight time9 hr 55 min
Time difference420 min
Flight typeInternational
01

Departure

Scheduled departure: 2026-10-29 17:45 (UTC-07:00). Confirm airport transport and terminal opening hours in advance.

02

Arrival

Scheduled arrival: 2026-10-30 10:40 (UTC+00:00). Arrange pickup, hotel and onward transport for the arrival date.

03

Time zones

Departure: Seattle (UTC-07:00); arrival: London (UTC+00:00).

DL20 On-time Performance & History

Methodology

93%Arrival on-time rate
Sample flights93 (flights)
Average departure delay-
Average arrival early-
Cancllation rate-
Longest delay119 min
Early arrivals-

Historical statistics are for reference only and do not predict future flight performance.

Aircraft, Cabin & Services

Based on currently published aircraft and cabin information; the operating aircraft may change.

Published aircraft type

Airbus A330-900neo

Economy 31 in

Seat layout290

Business 28 · Economy 262

Business Class1-2-1

Seat configuration depends on the operating aircraft

Economy Class2-4-2

31 in

MealsComplimentary snacks and drinks on flights over 250 miles; meals on long-haul international

Inflight entertainmentDelta Sync seatback screens or Delta Studio on personal devices

Inflight Wi-Fi

Availability and fees depend on the flight

PowerBusiness: USB port and power outlet; Economy: USB port and power outlet

BassinetAvailable

Accessibility-

DL20 Airports

Terminals follow the published schedule; check official airline channels for same-day gates and operations.

Seattle–Tacoma International Airport Departure & London Heathrow Airport Arrival Guide

Departure date: 2026-10-29. Terminal and arrival information helps plan your journey.

SEA

Departing from Seattle–Tacoma International Airport

DL20 is scheduled to depart from D. Allow time for international check-in, baggage drop, security and immigration.

LHR

Arriving at London Heathrow Airport

Scheduled arrival is at T3. After immigration, take the MRT, taxi, ride-hailing service or airport bus to the city.

+1

Planning your arrival

Scheduled arrival: 2026-10-30 10:40. Use the arrival date when booking hotels and pickup services.

Flight Changes, Cancellations & Missed Flights

If the schedule or aircraft changes, follow the booking channel and operating carrier rules.

01

Schedule changes

After an airline or booking-platform notice, confirm the new date, terminal and connecting transport.

02

Cancellation and changes

Refund, rebooking and involuntary-change rules depend on the booking channel, fare conditions and airline notice.

03

Missed flight

If you may not reach the airport on time, contact the booking channel or airline quickly to protect later sectors.

Check-in, Baggage & Entry Tips

International check-in deadlines, baggage allowance and entry requirements may vary by fare and traveller.

01

Arrive early for check-in

Arrive at least 3 hours before departure. Counter opening times and online check-in rules follow Seattle–Tacoma International Airport guidance.

02

Check baggage allowance

Checked and carry-on baggage allowances depend on cabin, fare rules and membership tier. See the baggage terms in your booking.

03

Prepare entry documents

Before departure, check passport validity, visa or visa-free eligibility, andLondon Heathrow Airport’ latest arrival declaration requirements.

What should I check before flying DL20?

01

Check the departure date

For an overnight flight, check the departure date on your ticket and plan airport transport in advance.

02

Confirm the operating carrier

Follow the airline rules shown in your booking for check-in and checked baggage.

03

Check boarding information

Gates and operating times may change; follow airline notices and airport displays.

Popular route recommendations

DL20 Frequently Asked Questions

Which airline operates this flight?

DL20 is operated by Delta Air Lines.

Where does it depart and arrive?

Seattle–Tacoma International Airport (SEA) → London Heathrow Airport (LHR).

What are the departure and arrival times?

Scheduled departure 17:45, arrival 10:40 · 9 hours 55 minutes.

Which terminal is used for check-in?

Departure terminal D, arrival terminal T3. Check-in, gate and baggage belt are announced on the day.

Are meals and inflight entertainment available?

Meals: Complimentary snacks and drinks on flights over 250 miles; meals on long-haul international. Inflight entertainment: Delta Sync seatback screens or Delta Studio on personal devices.

Explore This Route

Departure airportFlights from Seattle–Tacoma International Airport
Arrival airportLondon Heathrow Airport information
Operating airlineDelta Air Lines information