The 1993 Auckland mid-air collision was an aircraft accident in New Zealand. It occurred on 26 November 1993, when two aircraft operated by Airwork, under contract to the New Zealand Police, collided and crashed in central Auckland. The mid-air collision of the Aérospatiale TwinStar helicopter and Piper Archer aeroplane resulted in the deaths of all four occupants – a civilian Airwork pilot on each aircraft and two New Zealand Police officers on the helicopter. The accident occurred in daylight with excellent visibility, in uncontrolled airspace (class G), with both aircraft flying under visual flight rules. Both the helicopter and aeroplane were operated by Airwork (NZ), and working under contract to the New Zealand Police at the time of the accident. The Transport Accident Investigation Commission investigation found the accident occurred because neither pilot saw the other aircraft. Aérospatiale aircraft The Aérospatiale TwinStar AS 355 F1, registration ZK-HIT, was using call signs "Police One" with air traffic control and "Eagle" with police control. It was operating out of Mechanics Bay Heliport, the base of the police Air Support Unit, 1 NM east of the central city. The helicopter performed ad hoc missions around the city, usually at 1,000 feet AMSL, and on 26 November was being piloted by Ross Jeffree Harvey (aged 41), with Police Air Support Unit officers Sergeant Lindsay Eion "Lou" Grant (39) and Constable Alastair Alan Sampson (27). At 4:22 pm it returned to the heliport after a routine mission for a break of about an hour, and was logged taking off again at 5:33 pm. It departed to the north over Waitematā Harbour and shortly afterwards made a turn to the left to a southwest heading. It flew this course, climbing, for about 1 minute before making a 30° turn to the left, continuing climbing through 1,200 feet until the accident 18 seconds later. Piper aircraft The Piper Archer 28-181, registration ZK-ENX, call sign "Pact 1" (Police Airborne Control of Traffic) was flying a regular weekday traffic patrol, piloted by Allan Anthony Connors (aged 27). The patrols were normally conducted at 1,500 feet. It left Ardmore Aerodrome at 3:59 pm, and reported on several traffic incidents. Shortly after 5:32 pm, the aircraft flew south from the North Shore to a road accident on the Auckland Southern Motorway near the Symonds Street on-ramp. It flew southeast past the road accident, and began a turn to the left around