Veteran pilot John Funnell wants to raise tens of thousands of dollars to fund the legal battle for the pilot who was one of the first on the scene after the Whakaari White Island eruption.
Mark Law is the director of Kahu Helicopters, one of the ten organisations WorkSafe has charged for health and safety breaches.
Kahu is among at least three helicopter companies which operated tours to the island.
The charges relate to events before the eruption and have nothing to do with the rescue and recovery afterwards.
John Funnell was also in the air during the rescue directing the helicopters and communicating with those on the mainland.
He told reporter Charlotte Cook an appeal has been set up to fund Mark Law's legal battles as his business is now close to collapse.