Members-only airline Surf Air announced Thursday selling the 2000th membership for its “all-you-can-fly” business model. The Santa Monica startup more than doubled its members since the start of the year when it had about 850 members. The 2000th membership was sold to David Ritterbush, chief executive of potato and veggie chip maker Pop Chips, in Playa Vista. Surf offers daily nonstop flights from Burbank Bob Hope Airport to San Carlos in the San Francisco area, and Truckee/Lake Tahoe. Service to Oakland starts this month, with flights to Palm Springs beginning in November. Memberships start at $1,750 a month. Chief Executive Jeff Potter said the response the company has received from members will result in speeding up deliveries of more single-engine Pilatus PC-12 aircraft. Surf started the year with six aircraft, and will bring on nine additional planes during 2016. “By the end of 2016, we will be more than doubling the size of the Surf Air fleet,” Potter said in a prepared statement.