Earlier today I wrote about American putting a 3-cabin aircraft once a day on Boston – Los Angeles.

Coach bookings were allowing seat assignments in business class, since it’s coded as a two cabin flight. (Business class should get economy service, but flat seats.)

For those who want to fly cross country in American’s three-cabin fully flat first class seats which are arranged one-one (each seat is both an aisle and a window seat) there’s a more economical way to do it than buying first class Boston – Los Angeles directly.

You can book Washington National – Boston – Los Angeles in first class, selecting this Boston – LA flight, from $518.

I’ve checked other starting cities — Philadelphia, New York LaGuardia and JFK, Charlotte, Chicago — and DC was the least expensive option.

Bear in mind that booking the Boston – Los Angeles flight in first gets you the seat but it comes with standard domestic first class service. There’s no lounge or premium meal component.

(HT: Ryan R.)