American Airlines and JetBlue have just announced another major expansion in New York and Boston.Fueled by the two carriers’ nascent Northeast Alliance, the carriers are adding a slew of new routes, touching down in new countries and improving the passenger experience both on the ground and in the air.Let’s dive into the details.Highlights: 7 key takeaways as American, JetBlue expand again in NortheastStay up-to-date on airline and aviation news by signing up for our brand-new aviation newsletter.American Airlines will add new India flight, 7 new routesThe Northeast Alliance is fueling American’s long-haul ambitions from New York-JFK.On Wednesday, the carrier announced its newest international service, to New Delhi (DEL) beginning Oct. 31, with three-weekly flights from JFK. The route will operate daily during the peak holiday period from Nov. 17 to Jan. 3. Cirium schedules show that AA last served Delhi with flights from Chicago (ORD) in March 2012.American will deploy its 273-seat Boeing 777-200 on the 7,318-mile route. The aircraft is equipped with 37 business-class pods, 24 premium economy recliners and 212 coach seats.New Delhi joins four other new AA long-haul routes from JFK, including Athens (ATH) launching on June 3, Tel Aviv (TLV) starting May 6, and Santiago (SCL) and Rio de Janeiro (GIG) beginning in the coming months.Sign up for our daily newsletterEmail addressSign upI would like to subscribe to The Points Guy newsletters and special email promotions. The Points Guy will not share or sell your email. See privacy policy.Domestically, American will add the following six routes, split equally between Boston and New York LaGuardia (LGA):DestinationOriginCincinnati (CVG)Boston (BOS)St. Louis (STL)Boston (BOS)Toronto (YYZ)Boston (BOS)Houston (IAH)New York LaGuardia (LGA)Oklahoma City (OKC)New York LaGuardia (LGA)Omaha, Nebraska (OMA)New York LaGuardia (LGA)All of the carrier’s new domestic routes will launch on Nov. 2. Most will be operated by American Eagle affiliate Republic Airways on the Embraer 175 regional jet. American will fly the LGA to IAH and BOS to STL flights with its 128-seat Airbus A319.As part of the news, American has also reaffirmed its commitment to remove all 50-seat regional aircraft from New York by the summer in favor of larger jets that feature both a first-class and coach cabin. (American recently made a similar move for its Washington, D.C., routes.)JetBlue is adding 17 routes, 2 new countries, 7 new citiesThanks to the partnership, JetBlue will land in Canada and Honduras for the first time beginning later this year. Additionally, the New York-based carrier is adding service to cities across the Midwest and the southern U.S., as well as to points in Mexico, with 17 new routes. To fuel the growth, the carrier will return the majority of its parked aircraft to service.You’ll find a full list of new JetBlue routes below:DestinationOrigin(s)Launch detailsSan Antonio (SAT)Boston (BOS), New York-JFKOctober 2021San Pedro Sula, Honduras (SAP)New York-JFKDecember 2021Puerto Vallarta, Mexico (PVR)New York-JFKFirst quarter 2022Kansas City (MCI)Boston (BOS), New York-JFKSecond quarter 2022Milwaukee (MKE)Boston (BOS), New York-JFKSecond quarter 2022Vancouver (YVR)Boston (BOS) - Seasonal, New York-JFKSummer 2022Asheville, North Carolina (AVL)Boston (BOS) - SeasonalSummer 2022Jacksonville (JAX)New York LaGuardia (LGA)October 2021Sarasota-Bradenton (SRQ)New York LaGuardia (LGA)October 2021Savannah (SAV)New York LaGuardia (LGA)October 2021New Orleans (MSY)New York LaGuardia (LGA)First quarter 2022Nashville (BNA)New York LaGuardia (LGA)Second quarter 2022Portland, Maine (PWM)New York LaGuardia (LGA)Summer 2022Many of the launch details for the new routes, such as frequency, aircraft type and commencement date, remain up in the air, but JetBlue promises more information in the coming months. Of course, everything is subject to change due to pandemic-related travel restrictions and demand forecasts.As noted, Vancouver will be JetBlue’s first city in Canada, a milestone for the nearly 22-year-old carrier that’s long heard requests to begin flying north of the border.“Almost since day one, both our customers and crewmembers have been asking us to add flights to the middle of the country and into Canada,” said Scott Laurence, JetBlue’s head of revenue and planning.American and JetBlue jets. (Photo by Ryan Patterson/The Points Guy)Domestically, much of the growth is split between Boston (BOS), New York-JFK and New York LaGuardia (LGA). Many of the new BOS and JFK routes expand JetBlue’s footprint in the central U.S., while the LGA flights offer a mix of destinations for both leisure and business travelers.JetBlue specifically calls out its “targeted growth plan at LaGuardia” as a key priority of the Northeast Alliance. In fact, with Wednesday’s announcement, the carrier is tripling in size at LGA.JetBlue is planning to operate more than 24 daily LGA departures by the end of the year, which will climb to more than 50 by summer 2022.Existing markets will also see a notable boost. JetBlue promises additional frequencies between LGA and the following seven cities:Boston (BOS) – up to 15 daily roundtrips in 2022Charleston, South Carolina (CHS)Fort Lauderdale (FLL)Fort Myers (RSW)Orlando (MCO)Tampa (TPA)West Palm Beach (PBI)An improved connecting experience at JFKThe two carriers have teased an improved connecting experience at New York-JFK, and now we have the details. Launching this summer, the airlines will offer an airside bus running between JetBlue’s Terminal 5 and American’s Terminal 8 at JFK. Of course, it’d be great if the airline could co-locate in the same terminal, but space constraints currently make that impossible.Connecting at LaGuardia will be much more of a hassle. JetBlue operates from the Marine Air Terminal, which requires a pre-security bus ride to American’s Terminal B. It remains to be seen if JetBlue ultimately moves terminals at LGA, but it’s definitely a possibility, considering Spirit is moving into the already-congested Marine Air Terminal.Premium transcon gets a boostAmerican Airlines is bringing its premium-heavy Airbus A321T to Boston. The 102-seat jet, outfitted with a first-class, biz and coach cabin, will be deployed on all of AA’s flights between BOS and Los Angeles (LAX).This joins the existing A321T service from New York-JFK to LAX, San Francisco (SFO) and soon-to-launch Orange County (SNA).JetBlue will continue flying its Mint-equipped Airbus A321s from BOS, JFK and EWR to five West Coast cities: Los Angeles (LAX), San Francisco (SFO), San Diego (SAN), Seattle (SEA) and Las Vegas (LAS).Reciprocal loyalty benefits are comingIn the coming weeks, American and JetBlue will add reciprocal loyalty benefits, starting with the ability to earn points or miles on either carrier. The details are still forthcoming, but this is the first timeline that we’ve seen so far for this much-anticipated offering.The airlines are also committed to adding award redemptions on either carrier, as well as elite benefits for frequent flyers, but no further details are available yet.This move comes in the face of major scrutinyWednesday’s announcement comes as the Northeast Alliance is reportedly drawing greater scrutiny from regulators and other airline competitors. The Wall Street Journal reported last week that the Justice Department is concerned that the deal could lead to anticompetitive coordination and increased fares in key markets. Spirit Airlines recently requested a full investigation into the Northeast Alliance.The Department of Transporation terminated its review of the Northeast Alliance under the Trump administration with some concessions from both carriers, including commitments to growth, slot divestitures at the capacity-controlled airports of New York-JFK and Washington/National (DCA) and other antitrust compliance measures.In JetBlue’s latest press release, the carrier writes that “with these new markets in both JFK and LaGuardia, JetBlue and American are demonstrating that commitment to growth.” Despite the challenges, the two carriers are moving forward with adding additional codeshare markets, 30 of which will launch on May 3 and 10 more in the coming months.Combined with 24 new routes, eight new cities and three new countries, the carriers are seemingly hopeful that this is enough growth and customer benefit to placate the regulators.