Airport in 1962 until traffic built up enough to use the Viscounts there. Four more secondhand -100s joined the fleet and five of the larger Fokker F27 Friendship Mk500s were purchased, three new and two secondhand, from 1973. NAC colours would return to the international Norfolk Island run, albeit under an Air New Zealand charter, with an Mk500 model flying the Auckland to Norfolk Is route. The Friendships served New Zealand for thirty years, latterly under Air New Zealand ownership, progressively being rundown through the 1980s before the last of the fleet was withdrawn in 1990. Jet power As early as 1959, when the first Vickers Viscounts were entering service, NAC management discussed when to equip with pure jet aircraft. In 1963 NAC hired a de Havilland Comet 4 from Christchurch to Auckland covering the distance in 1 hour and 20 minutes. The decision to equip with jet aircraft was finally made by the NAC board of directors in 1965. After a global tender was let, three twinjet aircraft were shortlisted, the BAC 1-11, Douglas DC-9 and the Boeing 737. The main criterion for the candidate aircraft was the ability to safely fly in and out of Wellington Airport's unique right-hand inner harbour circuit. When NAC management chose the new Boeing aircraft over the already proven BAC 1-11, the pro-British-leaning National Government promptly turned down the request for precious funds and told NAC to redo their sums again. NAC rebuffed the government's order and argued that the Boeing 737 was the best fit for the growing network. So confident was the airline that Boeing secured early delivery slots on the production line for NAC. NAC won the Government over with the logic of simple economics: three 737-200s could do the job of four BAC 1-11s. The approval was given in late 1966 for the purchase of three 737-200s. Boeing 737 The first Boeing 737, ZK-NAC, arrived from Seattle via Hawaii and Fiji into Wellington airport in the new livery of "National Airways" all-white body, blue titles, with a red cheatline and striking red 'Godwit' roundel on the tail. With the arrival of ZK-NAD and ZK-NAE, full services were introduced in 1968 on the "main trunk" (Auckland–Wellington–Christchurch–Dunedin). Later this extended to Invercargill, Palmerston North and Hamilton in 1975 as more aircraft were added, including ZK-NAM which had been the Boeing 737-200 prototype, N1359B. Viscounts were retired as demand for jet services