Crowds turn out at Hawke's Bay Airport as Air New Zealand says goodbye to its last 737s.

Air New Zealand is preparing to sell its last two Boeing 737s, ending a 47-year relationship between the airline and the "workhorse" jet that has transported millions of passengers around the country over the decades.

Of the last two 737-300s the company owns, one has spent the past few weeks travelling the country on a public "farewell" tour.

On Wednesday it was at Hawke's Bay Airport, where hundreds of people took the opportunity to take a walk through the aircraft.

SIMON HENDERY/ FAIRFAX NZ One of Air New Zealand's last two remaining Boeing 737-300 aircraft at Hawke's Bay Airport as part of a national "farewell" tour ahead of it being sold by the airline.

The first Boeing 737-200 entered service with NAC, which later merged with Air NZ, in September 1968. The fleet subsequently made 825,000 flights during its years with the airline.

The first aircraft in the more advanced 737-300 range joined the Air NZ fleet in 1998 and since then the airline has operated 23 of the models.

But they have since been phased out and replaced by newer, more efficient Airbus A320s.

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Air NZ's 737 fleet manager, first officer Gus Black, said crew had mixed emotions over the departure of the "workhorse" aircraft.

"It's sad in some respects in that you feel you're almost farewelling a friend. Forty-seven years is a long time to operate an aircraft," he said.

"We've had crews that have operated these aircraft for 30 or 35 years so for them it's somewhat sad to see it go but it's also pretty exciting they're being replaced by new aircraft – the latest and greatest."

The plane flies to Tauranga on Wednesday evening for a similar public farewell on Thursday.

After spending the weekend in Auckland, it will join the other 737 in Christchurch for pre-sales servicing. The planes are likely to be sold either for use by another airline, or for parts.

Black said he could not say how much the planes would fetch through the sales process, and the value of aircraft varied depending on the factors such as the air time and condition of their engines.