Question: What manufacturer was investigating the Wittman Big X and at one point was based in San Antonio, Texas?

Context paragraphs:
Wittman Big X: The Wittman Big X is a four seat high wing variant of the Wittman Buttercup.  The aircraft received serious attention from both Fairchild Aircraft, and Cessna Aircraft in the post World War II aviation boom.

List of San Antonio Spurs head coaches: The San Antonio Spurs are an American professional basketball team based in San Antonio, Texas.  They are a member of the Southwest Division of the Western Conference in the National Basketball Association (NBA).  The franchise was founded as the Dallas Chaparrals of the American Basketball Association (ABA) in 1967.  The team suffered from poor attendance and general disinterest by fans in Dallas, and the name "Dallas" was dropped in favor of "Texas" during the 1970–71 season in an attempt to make the team regional.  This also proved to be a failure, and the team returned full-time to use "Dallas" for the 1971–72 season.  The team was put up for sale after missing the playoffs in the 1972–73 season.  The team was acquired by a group of 36 San Antonio businessmen, led by Angelo Drossos and Red McCombs, who relocated the team to San Antonio, Texas and renamed it to Spurs.  In 1976, the ABA folded, threatening the future of San Antonio's sole professional sports franchise.  The NBA, however, decided to admit four ABA teams into the league, including the Spurs, along with the Denver Nuggets, the Indiana Pacers and the New York Nets.

Terrell Hills, Texas: Terrell Hills is a city in Bexar County, Texas, United States; it is located 5 mi northeast of downtown San Antonio.  As of the 2010 census Terrell Hills had a population of 4,878.  It is part of a group of three cities — Terrell Hills, Alamo Heights, and Olmos Park — located between Uptown San Antonio, Midtown San Antonio, Downtown San Antonio, and Fort Sam Houston (a U.S. Army post).  Terrell Hills is bordered on the west by Alamo Heights, on the east by Fort Sam Houston, on the north by Uptown San Antonio, and on the south by San Antonio's Near East Side.  It is part of the San Antonio Metropolitan Statistical Area.

Rena Maverick Green: Rena Maverick Green (February 10, 1874 – November 29, 1962) was an artist, a suffragist and a co-founder of the San Antonio Conservation Society.  She was a pioneer female member of the San Antonio School Board and served on the board of trustees of the San Antonio Public Library.  She was a preservationist for San Antonio history, including the San Antonio Missions National Historical Park and the saving of many city parks.  Green helped preserve the Spanish Governor's Palace and the San Antonio River Walk.  She was the granddaughter of a signer of the Texas Declaration of Independence, and the widow of a Texas state Senator.

University of San Antonio: The University of San Antonio was a Methodist institution of higher education located in San Antonio, Texas, USA.  It was founded as San Antonio Female College by Dr. John E. Harrison Sr. in 1894.  The name was changed to Westmoorland College in 1918 and to the University of San Antonio in 1937.  In 1942, the campus was taken over by Trinity University, which adopted the alumni of the University of San Antonio.  Trinity, in turn, built a new campus and left the old University of San Antonio campus in 1952.

San Antonio, San Pedro: San Antonio, officially known as Barangay San Antonio, is the largest barangay in the city of San Pedro, Laguna, Philippines.  With a land area of 780 hectares, San Antonio is Laguna's gateway to Metro Manila.  As of the 2010 census, the population of the barangay was 47,825.  It is adjacent to the city proper located at the northern portion of San Pedro.  San Antonio is the location of large factories in the city.  It is also one of the richest barangays of San Pedro.  The barangay is divided into two parts: the San Antonio Barangay Proper and Upper San Antonio.  Its patron saint is San Antonio de Padua.

San Japan: San Japan is a Japanese culture and anime convention held annually in San Antonio, Texas.  The event, which debuted in 2008, is San Antonio's first major anime convention and has developed into the largest Japanese fan-oriented convention in the city.  Many credit San Japan with forcing open the doors for big pop-culture conventions in the Alamo City, such as Alamo City Comic Con (established in 2013 and one of the largest and fastest growing comic conventions in the country).  San Japan was noted in the 2015 San Antonio Current City Guide "100 Things To Do In San Antonio Before You Die".

Fairchild Aircraft: Fairchild was an American aircraft and aerospace manufacturing company based at various times in Farmingdale, New York; Hagerstown, Maryland; and San Antonio, Texas.

Carl Wilhelm August Groos House (San Antonio): The Carl Wilhelm August Groos House is located in the Bexar County city of San Antonio in the U.S. state of Texas.  It was designated a Recorded Texas Historic Landmark in 1977.  Designed by Alfred Giles in 1880, the building contractor was John H. Kampmann.  Giles used a Victorian Gothic Revival on this limestone home.  Groos had immigrated from Germany to Texas in 1848, at which time he and his brothers started a freighting firm.  In 1871, he built the Carl W. A. Groos House in New Braunfels.  In 1872, he and his family settled in San Antonio.  Groos married Hulda Amalie Moureau and became a founding member of the Groos National Bank.  In 1880, Groos hired Giles to build his San Antonio home.  It is listed on the National Register of Historic Places listings in Bexar County, Texas as a contributing structure of the King William Historic District .  Groos died in 1893 and is interred at San Antonio City Cemetery No. 1.  In 1957, the house was purchased by the San Antonio Council of the Girl Scouts of the USA.  The Girl Scouts sold the home to Charles Butt.  It has been restored and is in private ownership.

Presidio San Antonio de Béxar: Presidio San Antonio de Béxar was a Spanish fort built near the San Antonio River, located in what is now San Antonio, Texas, USA.  It was designed for protection of the mission system and civil settlement in central Texas.  It also served to secure Spain's claim to the region from French, English and American aggression.  It was built by Franciscan priest Antonio de Olivares and the Payaya; and along with the Misión de San Antonio de Valero (the Alamo) and the Acequia Madre de Valero, is the origin of the present city of San Antonio, Texas.

Supporting paragraphs: Wittman Big X Fairchild Aircraft
Answer: Fairchild Aircraft