Bell UH-1H NZ3815 (c/n 13849) about to start up after a "P" stop at Rangiora just before lunch today.
This has been around longer than most of the aircrew aboard today. Initially built as serial 74-22525 for the US military - it was delivered to NZ in November of 1976 (to replace NZ3810).
"P" also = phuel.
Hangars doors in the background being closed prior to start up.