4B (4B)

4 non-stop routes across 4 airports. Main hub: Boston (BOS).

Live fares · BOS → MSS

About 4B

4B is a small regional carrier operating a tight domestic network across the northeastern and northwestern United States. With just four non-stop routes spread across four airports, this isn't an airline you'll stumble onto while searching for a transatlantic deal — it's built for point-to-point regional travel, connecting smaller markets that larger carriers have mostly abandoned. The main hub sits at Boston's Logan International (BOS), though the network leans on secondary airports like Massena (MSS), Pendleton (PDT), and Portland (PDX). Total network span clocks in at 1,424 km, which tells you everything about the scale here.

Why fly 4B?

The honest answer is convenience. If you're trying to get between markets like Massena and Boston without renting a car or piecing together a connection on a major carrier, 4B fills a real gap. The BOS-MSS route at 420 km is the longest in the network, and on paper that's a short hop — but try driving it or finding a non-stop alternative and you'll appreciate what 4B actually offers. Regional carriers like this typically keep fares competitive because they're not fighting legacy airlines on the same routes. They're often the only game in town. That route monopoly can cut both ways on price, but it also means reliable frequency for travelers who need these specific city pairs. If your trip starts or ends at PDT or MSS, 4B deserves a serious look before you default to a connecting itinerary through a hub.

4B hub airports

Top destination countries on 4B

  • USA — 4 4B routes

Tips for booking 4B

Book directly through 4B's own channels first and compare against aggregators — regional carriers sometimes hold back inventory on third-party sites. Don't expect lounge access or frequent flyer partnerships typical of major alliances; this is a lean operation. Pack light if you can, since smaller regional aircraft often have strict carry-on overhead limits. The network covers all four airports with just one route each, so there's no built-in flexibility if your flight disrupts — have a backup plan, whether that's a rental car option or a refundable fare class. First-time flyers on 4B should treat this like a commuter service: functional, direct, and exactly right for the routes it serves.

Frequently asked questions about 4B

Where does 4B fly?

4B operates 4 routes primarily serving destinations across the United States. The airline focuses on connecting major US cities from its main hub.

What is 4B's main hub airport?

4B's main hub is Boston Logan International Airport (BOS), which serves as the airline's primary operational center and connection point.

Is 4B a legacy carrier, low-cost carrier, or regional airline?

Based on its network of 4 routes and focus on US destinations, 4B operates as a regional carrier serving domestic markets from its Boston hub.

When should I book flights with 4B, and what fare classes are available?

For the best fares, book in advance when possible, as prices typically increase closer to departure. 4B likely offers multiple fare classes to accommodate different travel needs and budgets.

What are 4B's baggage and check-in policies?

Baggage allowances and check-in procedures vary by fare class and booking type; it's recommended to review your specific ticket details or contact 4B directly for current baggage policies and online check-in options.

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Main hubs for 4B

Where 4B concentrates its operations — sorted by routes flown from each airport.

Where 4B flies most

Top destination countries by route count.

Related guides

Sibling pages from across Flightmaps — country aggregations, airport rosters, and visa context for 4B.

Top 4B destinations

4B network at a glance

Frequently asked questions about 4B

  • How many routes does 4B operate?

    4B (4B) operates 4 non-stop routes across 4 airports worldwide.

  • What is 4B's main hub?

    4B's busiest hub is Boston (BOS) in USA, with 1 non-stop routes from this airport alone.

  • What is 4B's longest route?

    4B's longest non-stop route is BOS-MSS at 420 km.

  • Where does 4B fly the most?

    4B flies most often to USA, with 4 routes serving destinations in USA.