A350 deliveries began in the second quarter of 2017, while the first A330-900neo flew in 2019. Delta retired the 747 on January 3, 2018, with its final revenue flight from Seoul-Incheon to Detroit (DL158) occurring on December 19, 2017, becoming the last major U.S. airline to fly the 747. On December 14, 2017, Delta ordered 100 Airbus A321neos, with 100 further options for $25.4 billion at list prices, to be delivered from 2020; equipped with Pratt & Whitney PW1100Gs and configured with a maximum capacity of 197 passengers, they will replace the airline's aging Airbus A319s, Airbus A320s, Boeing 757-200s, McDonnell Douglas MD-88s and McDonnell Douglas MD-90s. In a memo on March 18, 2020, to company employees, Delta CEO Ed Bastian announced that as a result of the COVID-19 pandemic impact on airline operations, they accelerated the retirement of the remaining MD-88s and MD-90s aircraft, as well as some older Boeing 767s. All the MD-88 and MD-90 aircraft were retired on June 2, 2020, with its final revenue flight from Washington-Dulles to Atlanta on MD-88 (DL88), and from Houston to Atlanta on MD-90 (DL90), becoming the last operator to fly the MD-90 and as well the last major U.S. airlines to fly the MD-88. The retirement of their MD-88s and MD-90s officially ended the 80-year era of Delta flying Douglas and McDonnell Douglas aircraft which started in 1940, with the DC-3. Furthermore, on May 14, 2020, Delta announced that the airline will be retiring their Boeing 777s as a result of the pandemic, and to further simplify their wide-body fleet in favor of the Airbus A350-900s. Delta underwent a cabin branding upgrade in 2015. The airline now offers or plans to offer six different cabin service options: Delta One, Delta Premium Select, First Class, Comfort+, Main Cabin, and Basic Economy. Availability and exact details vary by route and aircraft type. Delta One is the airline's premier business class product, available on long haul international flights, as well as transcontinental service from New York JFK to Los Angeles, San Francisco and Seattle/Tacoma. Delta One features lie-flat seating on all aircraft types, and direct aisle access from every seat on all types except the Boeing 757-200 (in which only a special sub-fleet of approximately 20 aircraft feature lie-flats).