[9] The grant of an interim certificate by the CAB in October 1962 to operate domestic military contract flights, intrastate and overseas charters from 1 April 1963 was followed by further fleet expansion, including the temporary lease of a pair of Lockheed L-1049 Super Constellations and the purchase of an L-749A in 1964.

[36][37] Further work to increase the growing jet fleet's utilisation was secured when the Federal Government awarded Modern Air a contract to carry military personnel between camps in the US.

Its Berlin-based fleet comprised Douglas DC-6 and DC-7 piston airliners, which were chartered by Flug-Union Berlin for its flying programme to several airports serving popular holiday resorts, chiefly in the Mediterranean.

[48] To enable Modern Air to operate its new CV-990s into Fort Myers Page Field with a viable payload, GAC agreed to co-finance the lengthening of one of its runways, which until then had been limited to revenue flights with jet aircraft no bigger than the Boeing 727-100.

Apart from the flight deck personnel (who were required to hold US, British or French passports under West Berlin commercial air transport regulations), all were local.

[60][38] While Modern's 990s were more expensive to operate than the dedicated short-/medium-haul jets of their British rivals in West Berlin due to higher fuel consumption and had more seats to fill, the airline compensated for these disadvantages with its single type fleet.

[64][23][28] Under the stewardship of Modern Air's newly appointed president,[nb 11][1] Thomas Ferguson, the airline's entire fleet was stationed at Tegel Airport from May 1972.

The increase in Modern's Berlin-based fleet resulted in a huge influx of capacity into the West Berlin charter market, where it faced stiff competition from UK rivals Laker Airways and Dan-Air.

This, as well as their diverse fleets comprising a number of different short-, medium- and long-haul narrow-body and wide-body aircraft, also enabled Modern's rivals to respond more flexibly and cost-effectively to seasonal peaks and troughs in demand.

It was thought that, in addition to picking up some of the lucrative contracts for an extensive short-/medium-haul West Berlin charter flight programme from Tegel Airport a consortium of three West German tour operators had awarded to defunct British rival Channel Airways in September 1970 (beginning in March 1971),[66] this would provide sufficient utilisation for the airline's additional Berlin-based aircraft and enable it to obtain better rates than in the city's heavily contested short-/medium-haul charter market.

[68][69] Similar to the case of the Bulgarian communist authorities' sudden and unexplained withdrawal of landing and overflight rights for flights originating/terminating in West Berlin (despite the much-needed hard currency Bulgaria earned from air navigation fees and airport user charges paid by the American and British airlines that operated these flights), some Western political observers at the time suspected behind-the-scenes East German lobbying of its Warsaw Pact ally and chief political backer respectively to have caused this to ensure East Germany's political and economic interests were not ignored in its Cold war allies' interactions with the West, especially where these concerned relations with West Berlin.

As a consequence of a general slowdown in global air traffic growth and committing to a large number of Boeing 747s that proved difficult to fill profitably, it had fallen into loss.

[74][75][76][77][78][73] The arrival of Modern Air's Hansa Jet at its Tegel base marked the first appearance of a German-built aircraft at the airport since the end of World War II.

[80][82][83][84] Pan Am's takeover of Modern Air's Saarbrücken route in February 1972,[85] which entailed serving it from the former's base at the rival Tempelhof Airport with 128-seat Boeing 727-100s,[85][86] was followed by the airline's unexpected suspension of Tempelhof–Saarbrücken services after less than a year's operation, citing insufficient demand.

[51] The setbacks Modern Air had suffered in 1972 and the CAB's displeasure at its management's decision to end all US operations necessitated a partial reversal of the previous strategy to focus all activities on West Berlin.

This entailed a reduction in the Berlin-based workforce and the return of three of eight aircraft to the US at the end of that year's summer season in November, in preparation for the resumption of limited charter services from the New York area in 1973.

[17] Steeply rising jet fuel prices in the aftermath of the 1973 oil crisis and Modern Air's reliance on the fuel-thirsty CV-990 had caused a significant increase in its operating costs.

A major disagreement over the fuel surcharge between Modern Air's management and its counterpart at Berliner Flugring, its main overseas business partner, led to a reduction in the Berlin-based fleet from five to four aircraft for the 1974 summer season.

[93] However, an attempt on Modern Air's part to pass on a further increase in its fuel surcharge to Berliner Flugring for the planned 1974/75 winter flying programme resulted in the tour operator's refusal to renew its long-standing charter contract with the airline.

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[94]).

[100][95] In March 1977, the CAB granted Seattle-based real estate developer Eugene Horbach permission to acquire the remaining assets of bankrupt Modern Air (including the rights to the name).

[59][101] The most important amongst these included As far as the former was concerned, compliance with contemporary regulatory restrictions on its operations in both the US and West Berlin, which were aimed at protecting bigger, established rival airlines, denied Modern Air access to potentially lucrative business opportunities that could have helped it to grow its presence in these markets as well as its economies of scale to enable it to spread its overheads over a greater level of activity.

Mindful of their main business unit GAC Properties' predominantly older, socially conservative clientele, they did not wish to be associated with such stunts and the controversy generated in many parts of the world.

[28][106][107][108] The special commemorative flight was arranged by Edward C. Bursk, chairman of the Admiral Richard E. Byrd polar research centre in Boston and editor of the Harvard Business Review.

The flight routed over the North Pole via Greenland, Alaska, the Philippines, Japan, Australia and New Zealand to Antarctica, where it made the historic landing at McMurdo Sound.

From there it routed over the South Pole, before crossing the International Date Line a second time and proceeding northwards to southern Argentina, Brazil, West Africa and Europe.

In common with other contemporary jet aircraft types, such as the Boeing 707/720, deHavilland Comet, Douglas DC-8, Sud Aviation Caravelle and Vickers VC-10, Convair's 880/990 lacked an auxiliary power unit (APU).

It also resulted in a subsequent collaboration between Modern Air's maintenance department and Garrett AiResearch to design and test a CV-990 APU, which was located in a hollow area behind the fuel tank inside the aircraft's inboard anti-shock body on the starboard wing.

This time the flight was operated by CV-990A N5615 Polar Bird II, which departed Los Angeles International Airport in early December 1970 with 60 wealthy, elderly passengers with an average age of above 70 on board and Captain Ross Zimmermann in command.

As a consequence (as well as owing to bad weather in the area at the time), when the flight departed Punta Arenas on 11 December on the last leg of the trip (before returning to the US) the closest Polarbird II came to the original South Pole experience of Polarbyrd I back in 1968 was to offer its passengers a 4,000 mi (6,400 km) round trip within a 950 mi (1,530 km) radius of the South Pole with views of the Antarctic icecap.