On February 14 1975 Moritz Suter and Peter Kalt found the "Business Flyers Basel AG". They bough a two engined Cessna 320 and a single engined Piper L-4 with two seats. In 1976 the capital is raised and a third aircraft is joining the fleet. Since the markets in Switzerland and Europe are regulated, the company are not able to perform scheduled flights and therefore are limited to air taxi services. Together with his wife, Moritz Suter writs a 100 paged operations manual. At the same time Moritz Suter is still a captain on Swissair's DC-9 aircraft. With the background of market deregulation in the United States and the raise of commuter airlines, Moritz Suter begins to develop a plan for an Europe wide operating Swiss regional airline. In a further step he is presenting his plan to the Swissair management which was interested in taking a stake of 40% of the company.

In 1978, thanks to the deregulation and liberalisation of the skies and the number of airline companies in Switzerland, there was scope for more players to compete with the monopoly of Swissair. The company starts to recruit its first employees, the company name is changed to Crossair AG. Crossair applies for traffic rights from Zurich to Lyon, Luxemburg, Nuremberg, Innsbruck, Klagenfurt and Lugano and signs options for 4 Swearingen Metroliner II. In 1979 the federal office for air traffic allows Crossair to operate scheduled flights from Zurich to Nuremberg, Innsbruck and Klagenfurt. In 1980 Crossair is allowed to operate flights from Zurich to Hannover and Düsseldorf as well as from Bern to Paris and from Zurich and Geneva to Turin. In October 1980 Crossair orders 10 33-seated Saab340 "Cityliner".   

In 1981, Crossair's third year of operation,  new flights operate between Zurich and Hannover, Rotterdam and Maastricht. Crossair is allowed to operate flights from Basel-Mulhouse. This was an excellent move for the Basel region since Swissair was just dropping most of the Basel flights at this time. In 1982, Crossair for the first time in history offered scheduled flights from Basel to Brussels, Geneva, Munich, Vienna and Zurich. After Swissair dropped the flights from Basel to Paris and Frankfurt, Crossair took over these flights. It became clear that Crossair’s product, operating with small aircraft and with a good schedule, was a success. 

In 1983, Crossair opens it’s maintenance base in Basel. In 1987 Crossair sells its last Metroliner and orders 3 additional Saab340. In 1988 Crossair and Saab announce to build a new turboprop aircraft: the Saab2000 Concordino! Swissair and Crossair intensify it’s wet-lease agreements. Crossair buys 5 Fokker50 and orders 25 Saab2000 aircraft as well as 4 Avro RJ85 in 1989. 

In 1991 Fokker 50 are operated. Swissair then takes over the majority of Crossair as it realises it is now a serious threat. In Basel, the airline opens it’s conference and training centre with various simulators. In 1993 Swissair buys more Crossair stocks and now owns 56.1% of Crossair. A new Livery which shows its proximity to Swissair is introduced. Saab 2000 makes it's first flight, and Avro RJ 85's are introduced to the Swissair fleet 

The Swissair group decides to give all flights up to hundred seats to Crossair in 1994. Crossair orders 12 Avro RJ100. In the same year, Crossair took over the medium-range business of Balair/CTA. Therefore, several MD82/83 joined the Crossair fleet and shall be the largest aircraft ever operated by Crossair. In 1996 Crossair gets their first Avro RJ100's and orders new Embraer 145 jets. The SAirGroup is created in 1997, and Crossair becomes part of the SAirLines Company. 

As the launch customer of the new ERJ-170 and ERJ-190 programs, Crossair has signed a purchase agreement for 30 firm orders for both the 70-seat ERJ-170 and the 108-seat ERJ-190-200 regional jets in 1999. In addition, Crossair placed options on a further 100 aircraft, but these orders will later be cancelled by Swiss, and delivery of the aircraft never took place. In 2000, Crossair takes over their first new Embraer 145 jets. 2001 was a turbulent year at Crossair due to financial instability of parent SAirGroup. In  2002, Crossair's Embraer 170 makes it's first flight in Crossair colours, although it never got delivered as the parent company,  SAirGroup goes bankrupt, and Crossair is radically changed to become the new SWISS International Air Lines, taking over Swissair's Operations on April 1st, 2002 to become Switzerland's national airline.