Departure
Scheduled departure: 2026-10-29 19:40 (UTC-07:00). Confirm airport transport and terminal opening hours in advance.
AS100 Seattle–Tacoma International Airport to London Heathrow Airport nonstop flight: schedule, airports, aircraft and travel guide.
AS100 Flight Overview
AS100 is operated by Alaska Airlines and connects Seattle–Tacoma International Airport (SEA) and London Heathrow Airport (LHR). Scheduled departure: 2026-10-29 19:40 (UTC-07:00); scheduled arrival: 2026-10-30 12:20 (UTC+00:00).
AirlineAlaska Airlines
Flight numberAS100
RouteSEA to LHR
Scheduled duration9 hr 40 min
Seattle to London Route Information
AS100 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 40 min
Time difference420 min
Flight typeInternational
Arrival
Scheduled arrival: 2026-10-30 12:20 (UTC+00:00). Arrange pickup, hotel and onward transport for the arrival date.
Time zones
Departure: Seattle (UTC-07:00); arrival: London (UTC+00:00).
AS100 On-time Performance & History
Methodology
97%Arrival on-time rate
Sample flights97 (flights)
Average departure delay30 min
Average arrival early10 min
Cancllation rate0%
Longest delay-
Early arrivals73%
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
Boeing 787
Economy 31 in; Business 76 in
76 in
Seat configuration depends on the operating aircraft
31 in
Availability and fees depend on the flight
AS100 Airports
Terminals follow the published schedule; check official airline channels for same-day gates and operations.
SEASeattle–Tacoma International Airport
Seattle, United States · UTC-07:00
- Departure terminal
- Check-in counter
- Announced on the day
LHRLondon Heathrow Airport
London · UTC+00:00
- Arrival terminal
- T3
- Baggage belt
- Announced on the day
Seattle–Tacoma International Airport Departure & London Heathrow Airport Arrival Guide
Departure date: 2026-10-29. Terminal and arrival information helps plan your journey.
Departing from Seattle–Tacoma International Airport
AS100 is scheduled to depart from . Allow time for international check-in, baggage drop, security and immigration.
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.
Planning your arrival
Scheduled arrival: 2026-10-30 12:20. 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.
Schedule changes
After an airline or booking-platform notice, confirm the new date, terminal and connecting transport.
Cancellation and changes
Refund, rebooking and involuntary-change rules depend on the booking channel, fare conditions and airline notice.
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.
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.
Check baggage allowance
Checked and carry-on baggage allowances depend on cabin, fare rules and membership tier. See the baggage terms in your booking.
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 AS100?
Check the departure date
For an overnight flight, check the departure date on your ticket and plan airport transport in advance.
Confirm the operating carrier
Follow the airline rules shown in your booking for check-in and checked baggage.
Check boarding information
Gates and operating times may change; follow airline notices and airport displays.
Popular route recommendations
AS100 Frequently Asked Questions
Which airline operates this flight?
AS100 is operated by Alaska Airlines.
Where does it depart and arrive?
Seattle–Tacoma International Airport (SEA) → London Heathrow Airport (LHR).
What are the departure and arrival times?
Scheduled departure 19:40, arrival 12:20 · 9 hours 40 minutes.
Which terminal is used for check-in?
Departure terminal No data, arrival terminal T3. Check-in, gate and baggage belt are announced on the day.
Are meals and inflight entertainment available?
Meals: Meal included. Inflight entertainment: On-demand entertainment.
Explore This Route
Departure airportFlights from Seattle–Tacoma International Airport
Arrival airportLondon Heathrow Airport information
Operating airlineAlaska Airlines information