And he wouldn't rule out working full-time for the clothing brand in the future.
Fyfe, who also sits on the boards of Trilogy and Antarctica NZ, said Wellington-based Icebreaker - whose products are made from merino wool from the South Island high country - had massive growth potential and he was excited to be playing a part in it.
"Icebreaker's got great mojo."
Fyfe, who left Air New Zealand late last year, has been credited with driving a turnaround in the airline's strategy and culture, as well as keeping it profitable during tough economic times.
Icebreaker is already one of the country's global business success stories, with 400 staff around the world and stores across Australasia, Europe and North America.
Fyfe said the clothing brand, which will have a turnover of around $190 million this year, had reached a point where his involvement could help it get to the next level.
He reckons Icebreaker has the potential to grow to the size of outdoor giant North Face, which posted revenue of US$1.7 billion in 2011 and is aiming to hit total sales of US$3 billion by 2015.
Founder and chief executive Jeremy Moon said Fyfe would play a critical role in Icebreaker's next five-year growth phase.
Moon wants to double the firm's revenue to almost $400 million by 2018, but said he was also conscious of the competitive threat posed by Icebreaker's competitors picking up on the benefits of merino wool and increasingly offering products made out of the material.
"I don't want [Icebreaker] to be the company that almost made it."
Moon said Icebreaker was evolving from a wholesale to a multi-channel business.
The company is boosting its internet presence and he said about 20 per cent of its sales in the United States were now being made online.
Moon said Icebreaker, which has just opened an Auckland office in Karangahape Rd that will be staffed by 20 people by this time next year, had recently appointed a head of online sales.
Greg Smith, the general manager of Michael Hill Jeweller, was joining Icebreaker as its head of Australia and New Zealand, he said.
Moon said the company was on the lookout for a head of marketing and would also hire 10 Auckland-based marketing and graphic design staff over the next nine months.
The shareholders of privately owned Icebreaker include Moon and Sir Stephen Tindall's K1W1 fund.