This in turn resulted in the closure of Modern Air's Berlin Tegel base at the end of October 1974. The airline had carried over two million passengers during its seven-year presence in West Berlin, which roughly equated to the city's contemporary population. Nineteen seventy-four was Modern Air's last full year of operation, during which it recorded a $4.17 million operating loss and an $8.98 million net loss, respectively, while the total number of passengers carried decreased by 17.3% to just over 400,000 and FTKs collapsed by 46.2% to a mere 7,000 (compared with 1973). Modern's poor financial performance in 1974 was the worst among all US supplementals at the time. It was also a case of the smallest airline in this category recording the biggest loss. Business closure Having carried the airline's losses since 1967 and failed to secure a buyer for the entire business, GAC refused to invest any further in its airline subsidiary and instructed the airline's management to wind down operations and begin disposing of its fleet in 1975. This resulted in the sale of three CV-990s. It also resulted in a labour dispute that saw the airline's last remaining seven pilots walk out on 1 September after abandoning the last two active CV-990s (out of a remaining airworthy fleet of five) at New York JFK and Chicago O'Hare, respectively. All remaining airworthy aircraft were parked at various US airports pending their eventual disposal. The last example was parked at Miami's Opa Locka Airport shortly before Modern Air ceased operations on 6 October 1975 in response to the CAB's decision to ground the airline, as a consequence of the regulator's unhappiness over GAC's refusal to commit new funds to the business (after filing for Chapter 11 bankruptcy protection earlier that year). In addition, the CAB ordered it to surrender its operating permit the following month (with effect from 20 November). Its West Berlin traffic rights were acquired by Aeroamerica, another US charter and supplemental carrier. Denver-based travel club and charter airline Ports of Call acquired most of the erstwhile Modern Air fleet. Four CV-990As saw active service with Ports of Call while a further two were cannibalised. Other former Modern Air CV-990As were acquired by Detroit-based Nomads travel club and the National Aeronautics and Space Administration (NASA). The aircraft acquired by NASA was used on the Space Shuttle programme as a landing systems research aircraft. In March