question: Who hijacked a flight taking off in San Francisco using Boeing's only model of trijet aircraft?
answer: Clay Thomas
context: Title: United Airlines Flight 696
  Passage: United Airlines Flight 696 was a flight from San Francisco International Airport in San Francisco, California, to Seattle, Washington, with 75 people in board.  After takeoff from San Francisco, Clay Thomas hijacked the Boeing 727, demanding the plane land in Oakland, California, and fuel up for a flight to Cuba.  The crew negotiated the release of all the passengers and cabin crew while on the ground in Oakland waiting for fuel.  Panicked by the sight of police vehicles, Thomas cut the fueling short and demanded an immediate departure to Cuba.  Once the plane was airborne, the pilot explained that the aircraft still did not have enough fuel to reach Cuba, and Thomas agreed to land in Denver, Colorado, for more fuel.  About 90 minutes after landing, the three members of the cockpit crew all jumped to safety from the open cockpit windows, all suffering injuries in the 18-foot (5.5-meter) jump.  Within five minutes of the escape and without hostages, Thomas meekly surrendered to the U.S. Federal Bureau of Investigation.  Thomas is currently incarcerated in a mental Institution in Colorado.
  Title: 1961 Holtaheia Vickers Viking crash
  Passage: The 1961 Holtaheia Vickers Viking crash (Norwegian: "Holtaheia-ulykken" ) was a controlled flight into terrain incident on 9 August 1961 at Holta in Strand, Norway.  The Eagle Airways (later, British Eagle) Vickers 610 Viking 3B "Lord Rodney" was en route from London to Stavanger Airport, Sola on an AIR Tours charter flight taking a school group for a camping holiday.  The aircraft was making an instrument landing when it crashed 54 km north east of Stavanger.  The accident killed all 39 people on board.
  Title: Boeing 727
  Passage: The Boeing 727 is a midsized, narrow-body three-engined jet aircraft built by Boeing Commercial Airplanes from the early 1960s to 1984.  It can carry 149 to 189 passengers and later models can fly up to 2700 nmi nonstop.  Intended for short and medium-length flights, the 727 can use relatively short runways at smaller airports.  It has three Pratt & Whitney JT8D engines below the T-tail, one on each side of the rear fuselage with a center engine that connects through an S-duct to an inlet at the base of the fin.  The 727 is Boeing's only trijet aircraft.
  Title: Air Costa
  Passage: Air Costa was an Indian regional airline headquartered in Vijayawada and based out of Chennai Airport.  It was owned by Indian business company LEPL Group.  The airline commenced operations as a regional airline in October 2013 using two Embraer E-170 aircraft with the first flight taking off from Chennai on 16 October 2013.  The airline got a permit for pan India operations in October 2016.  The airline focused on connectivity between tier II and tier III cities in the country and invested as of 2015.  Air Costa operated 32 daily flights to nine destinations from its focus cities Chennai and Vijayawada as of 2015.  The airline had a maintenance center in Chennai.  On 28 February 2017, it suspended operations until further notice.
citations: Boeing 727 United Airlines Flight 696