United Flight 3639 Deals & Information (2025/2026)

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United Flight 3639 Route Deals From $141

The cheapest prices found with in the last 7 days for return flights were $234 and $141 for one-way flights to Newark Liberty Intl. Airport for the period specified. Prices and availability are subject to change. Additional terms apply.

Wed, Aug 6 - Sat, Aug 9
MCI
Kansas City Intl.
EWR
Newark Liberty Intl. Airport
$234 Roundtrip, found 2 days ago
$234
Roundtrip
found 2 days ago
Select United flight, departing Wed, Aug 6 from Kansas City Intl. to Newark Liberty Intl. Airport, returning Sat, Aug 9, priced at $234 found 2 days ago
Thu, Sep 11 - Sat, Sep 13
MCI
Kansas City Intl.
EWR
Newark Liberty Intl. Airport
$286 Roundtrip, found 8 hours ago
$286
Roundtrip
found 8 hours ago
Select United flight, departing Thu, Sep 11 from Kansas City Intl. to Newark Liberty Intl. Airport, returning Sat, Sep 13, priced at $286 found 8 hours ago
Wed, Aug 27 - Fri, Aug 29
MCI
Kansas City Intl.
EWR
Newark Liberty Intl. Airport
$287 Roundtrip, found 5 hours ago
$287
Roundtrip
found 5 hours ago
Select United flight, departing Wed, Aug 27 from Kansas City Intl. to Newark Liberty Intl. Airport, returning Fri, Aug 29, priced at $287 found 5 hours ago

Frequently asked questions

What route does flight number UA3639 take?
Flight number UA3639 flies directly from ORD to BUF. During this trip, expect to be in the air for about 1 hour and 33 minutes. It pays to book ahead to secure your favorite seat.
What terminal does UA3639 fly out of?
Flight number UA3639 runs between ORD and Buffalo Niagara International Airport, and travelers with a seat on this flight usually board the aircraft from Terminal 2.
What kind of plane is on flight number UA3639?
The route for UA3639 is usually O'Hare Airport to Buffalo Niagara Intl. Airport (BUF), and the Embraer 170 is the type of aircraft you're likely to be flying with.
If I am not able to travel due to COVID-19, can I change my flight to a later date?
For more info about changing your UA3639 flight with Travelocity, please visit our Customer Service Portal.