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1993 Auckland mid-air collision
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Aviation incident in New Zealand
1993 Auckland mid-air collision Accident 1993 Auckland mid-air collision Piper Archer wreckage.jpg Fire crews attending the Piper Archer wreckage 26 November 1993 Mid-air collision Auckland, New Zealand -36.8583 174.7583 region:NZ-AUK_type:event inline,title 1 on ground 4 (all) 0 (none) Aerospatiale AS-355N Twin Squirrel front.jpg An Aérospatiale TwinStar, similar to the crash helicopter Aérospatiale AS 355 F1 Police Eagle Airwork (NZ), contracted to the New Zealand Police ZK-HIT Mechanics Bay Heliport 3 3 (all) File:ZK-ENX non.jpg ZK-ENX, the Piper Archer involved the collision Piper PA 28-181 Airwork (NZ), contracted to the New Zealand Police ZK-ENX Ardmore Aerodrome 1 1 (all)
The 1993 Auckland mid-air collision was an aircraft accident in New Zealand.Aerospatiale AS 355 F1 ZK-HIT and Piper PA 28-181 ZK-ENX, mid-air collision, Auckland City, 26 November 1993 http://www.taic.org.nz/AviationReports/tabid/78/ctl/Detail/mid/482/InvNumber/1993-020/Page/19/Default.aspx dead https://web.archive.org/web/20111003103149/http://www.taic.org.nz/AviationReports/tabid/78/ctl/Detail/mid/482/InvNumber/1993-020/Page/19/Default.aspx 2011-10-03 2009-05-06 Transport Accident Investigation Commission Investigation 93-0202 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.Four killed in mid-air collision 27 November 1993 Otago Daily Times 1 The accident occurred in daylight with excellent visibility,5 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.20
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.3
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 the accident site. The aircraft turned through about 270° and was turning through a southwest heading when the collision occurred. The accident interrupted a report the pilot was making to Police Control over the radio.3
Collision
thumb|right|Map of the flight paths over central Auckland, red is the Aérospatiale TwinStar helicopter, blue the Piper Archer
The collision occurred at 5:34:48 pm, near the intersection of Queen Street and Karangahape Road, at an altitude of about 1,400 feet. The left wing of the Archer separated, and the aircraft rolled, dived steeply, and crashed into the elevated carriageway on the Central Motorway Junction between the Northern and Southern Motorways. The wing landed on a church roof.3–4 The TwinStar lost the main rotor and transmission, and rear tail boom, vertical stabiliser, and rear rotor.4 It fell onto the Grafton Road on-ramp to the Northwestern Motorway, under Symonds Street Bridge, and a severe fire broke out, fuelled by 700 litres of kerosene.7 The main rotor and tail section fell into a cemetery by Karangahape Road.
Helicopter debris caused moderate facial burns to the driver of a car, who was taken to Auckland City Hospital. The accident created substantial traffic congestion,http://www.aucklandoperationalsupport.org.nz/history_responses.html https://web.archive.org/web/20120425122413/http://www.aucklandoperationalsupport.org.nz/history_responses.html dead April 25, 2012 Our History Auckland Operational Support 2011-10-30 which hampered emergency services responding to the scene. A witness at Mount Eden, 1.3 NM south of the site, caught the accident on video (after the collision).11
Investigation
thumb|right|Wreckage of the Aérospatiale TwinStar on the Northwestern Motorway link
The Transport Accident Investigation Commission was notified of the accident at 6:20 pm, and appointed J J Goddard Investigator in Charge. He began a field investigation later that evening.2 The wreckage was moved to a storage site prior to inspection, as it was causing a serious obstruction to major public highways.7 The wreckage inspection found the outboard 50 cm in on of the left wing had been cut off the Archer, and found matching damage on one rotor blade of the helicopter, including paint similar to the airplane primer.7
The U.S. Federal Aviation Administration conducted a cockpit field of view survey for the Commission. The relative angular position was plotted on the diagram from each aircraft, for 28 seconds prior to the collision. It showed the helicopter would have been visible to the Archer pilot, appearing for about ten seconds in the lower centre windscreen, before being obscured by the engine nose around 18 seconds before the accident. The diagram also showed the low position of the sun may have affected the pilot's ability to see the helicopter.11 For the TwinStar pilot, the aeroplane would have been visible only for a few seconds in the top left corner of the windscreen. The two observers in the helicopter, sitting in the left front and rear, had no obstruction preventing them seeing the approaching Archer.11
The Commission found the Airwork (NZ) Operations Manual specifically addressed collision avoidance between these two aircraft:13
5 Police Traffic Patrol
4. Heights at which the patrol is to be carried out at.
4.1. 1500' or lower depending on
—weather conditions
—required by ATC
—or in accordance with Reg 38 of the Civil Aviation Regulations
4.2. NB The Police Eagle Helicopter also operates in the same areas, and the pilots have agreed to carry out their operations at 1000' where possible
12. Miscellaneous
12.4 Under no circumstances is the Traffic Patrol aircraft to operate in close proximity to the Eagle Helicopter while the Helicopter is engaged on an incident. A good lookout is imperative and shall be maintained at all times.
Discussions with other pilots of the aircraft and police crew found they were familiar with the normal operating altitudes of 1,500 feet for the Police Traffic Patrol and 1,000 feet for the Police Eagle.13
The Commission found the accident occurred because neither pilot saw the other aircraft. Contributing factors were the helicopter not levelling at the agreed altitude, the helicopter did not establish mutual position by radio, and the helicopter crew did not see the traffic in time. It also cited the inherent limitations with the "see and avoid" method as a causal factor. The Commission recommended the Director of Civil Aviation promulgate a single advisory radio frequency for aircraft in the uncontrolled airspace between Auckland and Whenuapai Control Zones, which he did.20
Aftermath
Helicopter owner Vertical Flight successfully sued Airwork for damages of $1.5 million due to the loss of the helicopter, with the decision being upheld on appeal.Court upholds $1.5m fatal helicopter crash damages. The New Zealand Herald 30 June 2000
References
Sources
New Zealand Aviation Modern history
http://www.taic.org.nz/AviationReports/tabid/78/ctl/Detail/mid/482/InvNumber/1993-020/Page/19/Default.aspx Investigation 93-020 Transport Accident Investigation Commission 2009-05-06 https://web.archive.org/web/20111003103149/http://www.taic.org.nz/AviationReports/tabid/78/ctl/Detail/mid/482/InvNumber/1993-020/Page/19/Default.aspx 2011-10-03 dead
Category:1993 in New Zealand
Category:Aviation accidents and incidents in 1993
Category:Aviation accidents and incidents in New Zealand
Category:1990s in Auckland
Category:Mid-air collisions involving general aviation aircraft
Category:Mid-air collisions involving helicopters
Category:Mid-air collisions in Oceania
Category:November 1993 in Oceania