Question: Who was a founding member of the world's second alliance (after the U-FLY Alliance) to consist only of low-cost carriers (LCCs)?

Context paragraphs:
Ancillary revenue: In the airline industry, ancillary revenue is revenue from non-ticket sources, such as baggage fees and on-board food and services, and has become an important financial component for low-cost carriers (LCCs) in Europe, North America and other global regions.  Ancillary revenue has been defined as, “Revenue beyond the sale of tickets that are generated by direct sales to passengers, or indirectly as a part of the travel experience.”  Ancillary revenue has been further defined to include these categories: à la carte features, commission-based products, and frequent flier activities.

Jeju Air: Jeju Air (), based in Jeju City, Jeju-do, South Korea, is a South Korean low-cost carrier, the first to be founded in the country.  It offers scheduled domestic services between several cities in South Korea and Seoul as well as some destinations outside of Korea.  It is also a founding member of the Value Alliance.

U-FLY Alliance: U-FLY Alliance () is the world's first alliance of low-cost carriers, formed in January 2016 between founding members HK Express, Lucky Air , Urumqi Air, and West Air.  All four founding airlines are affiliated with the HNA Group, with a focus on Hong Kong, mainland China, and Southeast Asia, but they are currently seeking new members which are not affiliated with HNA Group.  Eastar Jet, a South Korean low-cost carrier, joined the alliance on 27 July 2016.

Lucky Air: Lucky Air () is an airline based in the "Xiángpéng Hángkōng Dàshà" (S: 祥鹏航空大厦, T: 祥鵬航空大廈) in Kunming, Yunnan, China.  It operates scheduled services from Dali to Kunming and Xishuangbanna, and plans to expand to other areas of China.  Its main base is Kunming Changshui International Airport.  The airline is one of the four founding members of the U-FLY Alliance.

Urumqi Air: Urumqi Air () is an airline headquartered in Ürümqi, Xinjiang, People's Republic of China.  It operates scheduled passenger services.  Its main hub is Ürümqi Diwopu International Airport in Ürümqi.  The airline is one of the four the founding members of the U-FLY Alliance.

Value Alliance: Value Alliance is an airline alliance formed in May 2016.  It is the world's second alliance (after the U-FLY Alliance) to consist only of low-cost carriers (LCCs).  However, it is the first pan-regional LCC alliance.  It comprises seven Asia-Pacific airlines: Cebu Pacific, Jeju Air, Nok Air, NokScoot, Scoot, Tigerair Australia and Vanilla Air, along with Tigerair who merged with Scoot under the Scoot brand.

United Airlines: United Airlines, Inc., commonly referred to as United, is a major U.S. airline headquartered in Chicago, Illinois.  It is the world's third-largest airline when measured by revenue, after American Airlines and Delta Air Lines.  United operates a large domestic and international route network, with an extensive presence in the Asia-Pacific region.  United is a founding member of Star Alliance, the world's largest airline alliance.  Regional service is operated by independent carriers under the brand name United Express.  Its main competitors are American Airlines, Delta Air Lines, and Southwest Airlines.

Charles de Gaulle Airport: Paris Charles de Gaulle Airport (French: "Aéroport de Paris-Charles-de-Gaulle" , IATA: CDG, ICAO: LFPG ), also known as Roissy Airport (name of the local district), is the largest international airport in France.  It is named after Charles de Gaulle (1890–1970), leader of the Free French Forces during the Second World War, founder of the French Fifth Republic and President of France from 1959 to 1969.  Charles de Gaulle Airport is located within portions of several communes 25 km to the northeast of Paris.  Charles de Gaulle Airport serves as the principal hub for Air France as well as a European hub for fellow SkyTeam alliance partner Delta Air Lines.  Additionally, the airport serves as a focus city for low-cost carriers Vueling and Norwegian Air Shuttle.

HK Express: Hong Kong Express Airways Limited, or HK Express (), is a Hong Kong-based low-cost airline which provides scheduled air service to twenty-eight destinations in Asia, including China, Japan, Korea, Cambodia, Myanmar, Vietnam, U.S. Territories, Taiwan and Thailand.  The airline's main hub at Hong Kong International Airport uses a fleet that consists exclusively of Airbus A320 family .  The airline is one of the four founding members of the U-FLY Alliance.

West Air (China): West Airlines Co. Ltd. (), operating as West Air, is a low-cost airline based in New North Zone, Chongqing, People's Republic of China, operating a scheduled passenger network to 18 domestic destinations out of Chongqing Jiangbei International Airport and one international one to Changi Airport in Singapore.  The company was established in March 2006 by its parent company Hainan Airlines, with the launch of scheduled services on 14 July 2010.  The airline is one of the four the founding members of the U-FLY Alliance.

Supporting paragraphs: Jeju Air Value Alliance
Answer: Jeju Air