While United promotes its business class as “Polaris” on many routes, in most cases it’s just the soft product — meaning the food, service, amenities and so on — that folks will receive since the majority of the actual physical seats are still being manufactured and delivered. The only plane you’ll find the real Polaris seats on for the moment are the new United 777-300ER aircraft, which as of this writing are generally being flown between San Francisco (SFO) and Hong Kong (HKG) and starting today between Newark (EWR) and Tel Aviv (TLV). Awards on those routes are difficult to find at the lowest saver level, so in most cases you’ll either have to pay cash or the ridiculously high standard award price.However, thanks to Ryan Ewing on Twitter, we’ve learned that if you’re free this weekend and live in Washington, D.C. or can easily get to the nation’s capital, there’s a one-time opportunity to fly in true Polaris class cheaply on miles. That’s because United appears to be flying one of its 777-300ERs this Saturday at 6:15pm from Dulles (IAD) to London-Heathrow (LHR).United’s 6:15pm flight from Washington Dulles to London this Saturday is a Polaris aircraft.The flight is technically listed as a 777-200, but when you open the seat map, it’s a 1-2-1 Polaris seat configuration and first class has been zeroed out, so this appears to be a 777-300ER. The actual aircraft is departing from its usual base in San Francisco to Washington as the 7:30am flight, though there don’t appear to be any Polaris mileage seats available on that leg. But at the moment, you can redeem for the Washington to London leg on Saturday for just 57,500 miles plus $80.60 in taxes and fees, which is a terrific deal for the entire Polaris experience.Air Canada’s Aeroplan shows this same flight available for just 55,000 miles.Or since United is a member of the Star Alliance, you can also book these seats via other Star Alliance partners and in some cases get an even better deal. For instance, Air Canada’s Aeroplan shows this flight available in business class for just 55,000 miles and a minuscule $7.70 Canadian dollars (~$5.60) in taxes and fees since Aeroplan doesn’t charge a close-in booking fee. Even if you don’t have any Aeroplan miles, you can transfer American Express Membership Rewards points to Aeroplan and they should arrive instantly.We don’t yet see where this particular aircraft is going next, but if you’re interested in a trip to Europe and have the flexibility to leave quickly — a tall order for normal folks but not that out of the ordinary for readers of The Points Guy — grab one of these tickets while you still can!H/T: Ryan Ewing via TwitterSign 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.