Alaska Airlines is adding a new — very unique — way to book and pay for your travel.The Seattle-based carrier is unveiling a new “Flight Pass” subscription that will be available beginning Wednesday, Feb. 16.Here are the details.Want more airline-specific news? Sign up for TPG’s free biweekly Aviation newsletter!Where’s the Alaska Flight Pass valid?The pass offers flyers a fixed number of economy round-trip flights to destinations within California, as well as on flights to Phoenix (PHX), Reno (RNO) and Las Vegas (LAS) for a fixed monthly fee.In total, the pass is applicable on 100 daily flights from 16 airports, with the full map below.(Map courtesy of Alaska Airlines)This includes the airline’s intra-California routes, as well as flights to Phoenix (PHX), Reno (RNO) and Las Vegas (LAS) from California.Flight Pass plansThe airline will offer two subscription plans, “Flight Pass” and “Flight Pass Pro,” which differ based on the advance-purchase requirement. The former requires booking at least 14 days before travel, while the latter offers same-day booking up to two hours before departure. You can’t make reservations more than 90 days before travel with either pass.“Flight Pass” starts at $49 per month, and the “Flight Pass Pro” begins at $199, with a detailed table with subscription fees below.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.When picking a pass, you’ll need to select the number of desired annual roundtrips, either six, 12 or 24.PlanFlight Pass Flight Pass Flight Pass Flight Pass Pro Flight Pass Pro Flight Pass Pro Monthly subscription fee$49$99$189$199$399$749Roundtrip credits received per month0.5120.512Subscription cost per trip$98$99$95$398$399$375Credits received per year6122461224When it’s time to book a trip, you’ll be on the hook for the applicable government taxes and airport fees on each flight, in addition to the monthly subscription fee and nominal fare.The airline estimates that the taxes and fees will run $14.60 per one-way segment, which is comprised of the $5.60 Sept. 11 security fee, and $9 in airport and other surcharges.Meanwhile, the “nominal fare” for most flights the fare will only be $0.01.Flights for peak periods will carry a higher “nominal fare,” and those fees will be disclosed during the booking process.Alaska likened the premium-fee segments to surge pricing with a rideshare service. During periods of peak demand, like flying to Los Angeles for the Super Bowl or going to Las Vegas for Valentine’s Day, expect to pay a bit more for each flight.Note that the pass is only applicable for round-trip tickets — one-way and multi-city fares aren’t covered, though it’s possible that’ll change down the line. Additionally, those purchasing the entry-level “Flight Pass” and “Flight Pass Pro” will need to wait until they earn a full credit (every other month) before making a redemption.Furthermore, credits expire — you must use your credits to book travel before you receive your next set of credits, which varies based on which plan you select. As such, you’ll need to maintain a regular cadence of travel to make the pass worthwhile.Purchasing a pass requires a 12-month subscription, and it can’t be canceled prior to the end of the annual term. Note that you’ll need to call to cancel your pass before the end of the year. Otherwise, it’ll auto-renew.Travelers interested in purchasing one of these new passes can visit Alaska’s new dedicated webpage, flightpass.alaskaair.com.Earning miles and elite benefits on Flight Pass“Flight Pass” bookings are treated as standard, non-saver (basic economy) fares — they’re eligible for full mileage accrual at a 100% rate based on the distance flown. These tickets will also count towards elite-qualifying progress.Elites are eligible for upgrades on “Flight Pass” bookings (Photo courtesy of Alaska Airlines)Mileage Plan elite members will also enjoy their full suite of perks on “Flight Pass” tickets, including free upgrades, checked bags and more based on tier.Changing or canceling a Flight Pass bookingModifying one of these tickets isn’t so seamless.For one, they can’t be changed online. You’ll need to call the dedicated Flight Pass Desk (888-885-0155) to make a change. Self-service options are coming soon.Note that all changes must be within the eligible markets and follow the advance-purchase requirements of your specific pass.You could instead cancel your trip and redeposit your credit at any time before departure. Your credit will only be returned to your account if it’s still valid.Is the Flight Pass worth it?At first glance, it seems like the “Flight Pass” offers a compelling value.The $49 per month (or $588 each year) “Flight Pass” for six annual round-trip flights equates to a $98 fare paid for each round-trip flight, before taxes and fees.With the “Flight Pass,” you’d need to make these bookings at least 14 days before departure. Advance-purchase fares vary, but many intra-California round-trips can exceed $200 (before taxes and fees), meaning that the pass would offer savings.Of course, this requires locking yourself into a subscription with Alaska, so you wouldn’t be able to fly a competitor airline should the fare be much lower.Meanwhile, $199 per month (or $2,388 each year) for six annual round-trip tickets equates to $398 for each round-trip itinerary. The “Flight Pass Pro” offers same-day booking within two hours of departure, which can offer an exceptional value when only walk-up fares are left.For instance, an Alaska nonstop flight from San Francisco (SFO) to Palm Springs (PSP) can run as high as $499 on the day of departure. If you need the utmost flexibility, then the pass would be your best bet — and it’d offer good savings.Ultimately, the devil’s in the details, and we’ll have to wait to see how many flights are subject to a premium-fee surcharge, which can quickly change the calculation.Bottom lineThis isn’t the first time we’ve seen an airline offer a “Flight Pass” option.Back in 2010, JetBlue famously offered an “All You Can Jet” subscription, which included unlimited travel for a fixed fee within the airline’s entire network for a month.That offer is now history, but it’s great to see Alaska giving a shot at a subscription-based flight model.Whether it sticks is anyone’s guess, but it’ll be interesting to watch from afar as an East Coast resident. Had I been based near one of Alaska’s California hubs, I might’ve even given the pass a shot.