The company that employed the two men issued a media statement this afternoon.
Aerospread Ltd, which also owns the downed topdressing aircraft, said the Civil Aviation Authority had been notified and was now investigating the accident, so it was inappropriate for the company to comment on the cause.
"We are working with the authority and providing them with all the information we have,'' Aerospread Ltd managing director Bruce Peterson said.
"Our primary concern is with our injured staff who are listed in critical and serious conditions in intensive care. We have spent time with the families at Hawke's Bay Hospital and we ask media to respect their wish for privacy at this difficult time.''
Mr Peterson said both injured men - the pilot and top-dressing loader/driver - were very experienced.
"We would like to thank emergency services and the Lowe Corporation Rescue Helicopter for their outstanding response to this accident, and hospital staff for their emergency care.''