Question: What is the main base of the airline co-founded by John Nicolaas Block?
Context: Chalk's International Airlines, formerly Chalk's Ocean Airways, was an airline with its headquarters on the grounds of Fort Lauderdale-Hollywood International Airport in unincorporated Broward County, Florida near Fort Lauderdale.  It operated scheduled seaplane services to the Bahamas.  Its main base was Miami Seaplane Base (MPB) until 2001, with a hub at Fort Lauderdale-Hollywood International Airport.  On September 30, 2007, the United States Department of Transportation revoked the flying charter for the airline, and later that year, the airline ceased operations. Transavia, legally incorporated as "Transavia Airlines C.V." and formerly branded as "transavia.com", is a Dutch low-cost airline and a wholly owned subsidiary of KLM and therefore part of the Air France-KLM group.  Its main base is Amsterdam Airport Schiphol and has further bases at Rotterdam The Hague Airport, Munich Airport and Eindhoven Airport.  Transavia maintains Transavia France as its French subsidiary. Buffalo Airways is a family-run airline based in Hay River, Northwest Territories, Canada, established in 1970.  Buffalo Airways was launched by Bob Gauchie and later sold to one of his pilots, Joe McBryan (aka "Buffalo Joe").  It operates scheduled passenger, charter passenger, charter cargo, firefighting and fuel services.  Its main base is at Yellowknife Airport (CYZF).  It has two other bases at Hay River/Merlyn Carter Airport (CYHY) and Red Deer Regional Airport (CYQF).  The Red Deer base is the main storage and maintenance facility.  The airline is also the subject of the History television reality series "Ice Pilots NWT". Johan Nicolaas Block (May 18, 1929, Amsterdam – April 11, 1994) was a Dutch aviation pioneer.  He was the co-founder of Martinair, founder of Transavia and Air Holland. Blue Wing Airlines n.v. is an airline with its head office on the grounds of Zorg en Hoop Airport in Paramaribo, Suriname.  The airline started operations in January 2002 and operates charter and scheduled services from Paramaribo to destinations in the interior of Suriname, Guyana, Brazil, Venezuela and the Caribbean area.  Its main base is Zorg en Hoop Airport.  The airline was on the list of air carriers banned in the EU; however, they were removed from the list as of 28 November 2007 as there were no proofs of any insecure opration.  As of 6 July 2010, however, the airline was banned once again as a result of accidents involving it's aircraft. City Airline AB was a regional airline based in the Air Cargo Building on the grounds of Göteborg Landvetter Airport in Landvetter, Härryda Municipality, Sweden.  It was privately owned and operated a medium-sized European network from its main base at Landvetter.  The airline was wholly owned by Investment AB Janus of Gothenburg and employed 110 staff (as of July 2007).  On 29 November 2011 the City Airline name was dropped after being acquired by Skyways, and all flights were then operated under the Skyways brand.  In May 2012 Skyways and City Airline filed for bankruptcy. Bahrain Air (Arabic: طيران البحرين‎ ‎ ) was an airline of the Kingdom of Bahrain, headquartered in the Mohamed Centre in Muharraq.  Its main base was Bahrain International Airport.  The airline flew to 16 destinations in the Middle East, Africa and South Asia.  In earlier statements the airline planned to increase its destinations to 23 cities by 2009 and up to 25 cities by 2010.  Prior to its voluntary liquidation in 2013, Bahrain Air flew to 17 destinations (flights to Alexandria were seasonal).  In 2012, the airline complained via local media about the measures undertaken by the Minister of Transportation, also the competing airline Gulf Air's head of restructuring committee when the airline's route schedule and frequencies were reduced by up to 30% without prior notice.  The airline, having sought every route possible to overcome the Minister's act of Conflict of Interest, declared bankruptcy on 12 February 2013.  The airline complained of conflict of interest. Nepal Airlines Corporation (Nepali: नेपाल वायुसेवा निगम ) is the flag carrier airline of Nepal.  Its head office is in the Nepal Airlines Corporation (NAC) Building in Kathmandu, and its main base is Tribhuvan International Airport, Kathmandu.  The airline was established in July 1958 as Royal Nepal Airlines Corporation (RNAC) to be Nepal's first airline.  The airline's first aircraft was a Douglas DC-3, used to serve domestic routes and a handful of destinations in India.  The airline acquired its first jet aircraft, Boeing 727s, in 1972.  As of May 2017, the airline operates a fleet of ten aircraft. Olympic Airlines (Greek: Ολυμπιακές Αερογραμμές , "Olympiakés Aerogrammés" – OA), formerly named Olympic Airways for at least four decades, was the flag carrier airline of Greece.  The airline's head office was located in Athens.  The airline operated services to 37 domestic destinations and to 32 destinations world-wide.  The airline's main base was at Athens International Airport, with hubs at Thessaloniki International Airport, "Macedonia", Heraklion International Airport, "Nikos Kazantzakis" and Rhodes International Airport, "Diagoras".  Olympic Airlines also owned a base at London Heathrow International Airport.  By December 2007, the airline employed about 8,500 staff. Tiger Airways Australia Pty Ltd, operating as Tigerair Australia, is an Australian low-cost airline.  It commenced services in the Australian domestic airline market on 23 November 2007 as Tiger Airways Australia.  It is a fully owned subsidiary of Virgin Australia Holdings.  The airline is based in Melbourne, Victoria, with its main base at Melbourne Airport.  The Civil Aviation Safety Authority of Australia (CASA) grounded the airline in 2011; as a result operating bases at Adelaide and Avalon were shut down and it initially only operated out of its Melbourne base after returning to the air.  On 7 March 2012, Tigerair announced the reopening of a second base at Sydney Airport.
Answer: Amsterdam Airport Schiphol