Flight UA100 — United Airlines

Route Details

• Airline: United Airlines
• Aircraft: Boeing 777-200ER
• Origin: Chicago O'Hare (ORD)
• Destination: London (LHR)
• Typical duration: 8h 40m

Know Before You Fly — UA100

• Check in online 24 hours before departure — it's free, takes 2 minutes, and locks in your seat.
• Verify your carry-on dimensions meet United Airlines size limits before leaving home — gate-check fees are avoidable and delays the boarding process for everyone.
• Download the United Airlines app and enable push notifications for gate-change and delay alerts — they travel faster than airport PA announcements.
• Check your portable charger: power banks above 100 Wh require airline approval; above 160 Wh are prohibited in carry-on regardless of airline.
• International flight: confirm passport validity (6 months beyond your return date), visa or eTA requirements, and duty-free import allowances at London.
• Arrive with time to spare: 3 hours before departure from Chicago O'Hare for international check-in, immigration processing, and security.
• Save the London airport baggage claim number in your phone before you fly — useful if a bag is delayed and you've already left the terminal.

Aircraft — Boeing 777-200ER

Features based on typical configuration — actual cabin may vary by airline and route.

Airport Guide

Route Intelligence — UA100: Chicago O'Hare → London

• Scheduled flight time: 8h 40m. Plan connections, pickups, and meals accordingly.
• Long-haul flight: exit rows and extra-legroom seats return far more value on a 6+ hour leg than a short hop. Check upgrade availability at online check-in — airlines often discount them 24 hours out.
• Consider downloading entertainment before boarding; cabin Wi-Fi can be congested during peak usage hours mid-flight.
• International departure: arrive at Chicago O'Hare (ORD) at least 3 hours before departure. Allow extra time for check-in queues, baggage drop, and international security — especially at hub airports like ORD.
• Confirm passport validity (6 months beyond return date), visa or eTA requirements, and duty-free allowances at your destination before leaving home.
• Full London Airport Guide → — terminals, ground transport, lounges, and baggage claim at LHR.
• This route operates a wide-body aircraft (Boeing 777-200ER). Window seats have just one neighbor and the extra overhead bin space means carry-ons almost always fit. Aisle seats give faster deplaning at London.

Seat Guide

The Boeing 777 uses a 3-3-3 economy layout (10 seats per row). Always choose an A, B, C (left block) or H, J, K (right block) seat — never center D, E, G, or H, which leave you with neighbors on both sides for the entire flight.

Travel Essentials

• TSA — What You Can Bring: Review prohibited items before packing.
• Power Bank Rules Checker: Verify your portable charger is airline-approved.
• Carry-On Size Checker: Confirm your bag meets United Airlines size limits.
• Weather at London: Check the forecast before you pack.
• TSA PreCheck: Enroll to speed through security on future trips.

Baggage

2nd checked bag: $45

Personal item (always free): 17 × 13 × 8 in

MileagePlus Premier members and eligible United card holders waive bag fees.

Full United Airlines baggage policy → · Carry-on size checker →

United Airlines — Contact & Support

• Official Website
• Online Check-In →
• Manage Booking
• Frequent Flyer: MileagePlus
• Customer Service: 1-800-864-8331
• Live Chat
• Help & Support Center
• App: App Store · Google Play
• Report Lost or Delayed Baggage
• Baggage Claim Hotline: 1-800-335-2247
• Alliance: Star Alliance
• Primary Hub: Chicago O'Hare

United Airlines airline profile & fleet →

Cabin Classes — United Airlines

United Airlines operates one of the largest route networks in the world, with a hub system centered on Chicago O'Hare, Denver, Houston, Newark, San Francisco, and other major cities. A founding member of Star Alliance, United has invested heavily in its Polaris long-haul business class and is rolling out Starlink satellite Wi-Fi across its mainline fleet, aiming to make it free and dramatically faster than legacy in-flight internet.

• Basic Economy: United's lowest fare — no seat selection until check-in on most fares, boards in the last group, and carry-on restrictions apply on some routes.
• Economy: Standard cabin with a free carry-on and checked personal item, seat selection, and full mileage earning.
• Economy Plus: Extra legroom seating (up to 6 more inches of pitch) in a dedicated cabin section near the front of economy. Free for Premier Gold and above.
• United Premium Plus: A premium-economy cabin on long-haul international wide-bodies with wider, more reclined seats, amenity kits, and priority boarding.
• United Polaris: United's flagship long-haul business class — fully lie-flat seats with direct aisle access on most wide-body aircraft, plus Polaris lounge access at select hubs.

📶 Wi-Fi: Available on most mainline aircraft; free on a growing number of routes. United is progressively installing Starlink satellite Wi-Fi across its regional and mainline fleet through 2025-2026, replacing older, slower satellite systems — availability still depends on which aircraft is assigned to your flight. Cost: Free for MileagePlus members on Starlink-equipped aircraft; otherwise roughly $8+ per flight.

Expert Tips — United Airlines

• Check the United app for your specific tail number before flying — Wi-Fi speed varies enormously between Starlink-equipped planes and older aircraft.
• Economy Plus seats can often be booked a la carte at checkout for less than the cost of a full upgrade — worth it on transcontinental or 5+ hour flights.
• United's 737 MAX 8 and most 777/787 wide-bodies have Polaris business class with direct aisle access from every seat — ask for these aircraft on long-haul routes when possible.
• MileagePlus has no blackout dates on standard award tickets — use the United app's map-based award search to find last-minute mileage deals.

If Your Flight Is Delayed

• Open the United Airlines app immediately — delay and gate-change push notifications arrive faster than PA announcements.
• If delayed 3+ hours due to a controllable cause, ask the gate agent about meal vouchers or hotel accommodation (overnight delays).
• Check alternate routings before the agent announces them — having a specific rebooking suggestion ready cuts wait time at the gate.
• Keep receipts for any meals or transport you pay for during a significant delay — airlines may reimburse reasonable costs under their customer commitment policies.
• US DOT rule: Airlines must offer a full cash refund if they cancel or make a "significant change" to your flight and you choose not to rebook.

Frequently Asked Questions

Other United Airlines Flights

• Flight UA1 — Newark (EWR) to San Francisco (SFO), Boeing 757-200, 5h 30m
• Flight UA2 — San Francisco (SFO) to Newark (EWR), Boeing 757-200, 5h 40m
• Flight UA50 — Chicago O'Hare (ORD) to Denver (DEN), Boeing 737-800, 2h 15m
• Flight UA150 — Newark (EWR) to Chicago O'Hare (ORD), Airbus A320-200, 2h 30m
• Flight UA200 — Washington (IAD) to Chicago O'Hare (ORD), Airbus A320-200, 1h 50m

All United Airlines seat guides & routes →

International Travel Tips

• Confirm your passport is valid for at least 6 months beyond your travel dates.
• Check whether your destination requires an Electronic Travel Authorization (eTA/ESTA/K-ETA) — apply online before departure.
• Arrive 3 hours early for international departures — customs, immigration, and security lines vary significantly by airport and time of day.