Spinning out of control
Lookout! Issue 24, March 2012
The women were launched together for a tethered parasail flight from a purposebuilt parasailing boat. In a parasailing flight, the parasail is released into the air and drawn back in to the boat by winch. The idea was first developed by the German navy in 1918 to tow sailors behind U-boats as observers.
The parasail carrying the two women had been winched into the air, and was being towed along at about 5 knots. When the boat was about 500 metres from shore, the parasail suddenly started to spin in circles and was blown hard out to the port side of the boat, which immediately capsized.
The skipper, winchman and three passengers on the boat – including a five-year-old boy – were thrown into the lake. They were at risk of being struck by the still-spinning propellers until the skipper managed to dive underneath the capsized vessel and stop the outboard motors.
Meanwhile, the parasail had stabilised, and was hanging in mid-air, still tethered to the capsized parasailing boat with both women entangled, but still in their harness.
The owner of the company was loading passengers onto another vessel from the shore when he looked up to see a trail of smoke rising from the distant parasailing boat. He immediately unloaded the passengers and sped to the scene.
The crew and passengers were recovered from the water and the towline to the parasail was cut free. The parasail descended into the lake and the two women were recovered unharmed. The parasailing company immediately suspended its operations.
- The parasail had an airspeed limit of 22 knots, and an optimum speed of 14 knots. At the time of the incident, the winds reached 24 knots, and the vessel was making 5 knots. This gave a combined airspeed of 29 knots, exceeding the parasail’s limit.
- Excessive airspeed tends to overpower a parasail, forcing it to spill the excess air out to one side or the other. The result is an out-of-control spin. As the parasail was still attached to the vessel, its sudden spin and lurch to the port side almost certainly caused the vessel to capsize.
- The women remained in the air for about 10 minutes before being lowered down. They had no injuries.
- The operator of this business was a newcomer to the field, which is only informally regulated. He had undergone a total of three days observation of other parasailing businesses in New Zealand and Australia before setting himself up to carry fare-paying passengers. He also trained his own staff, a decision which one experienced operator described as the ‘blind leading the blind’.
- As a guide, the New Zealand Parasail Association’s Rules and Standards recommend a minimum of two experienced crew, including a skipper with a minimum of 500 hours or 1,000 flights of logged parasailing operating experience, and a first mate with 25 hours of experience. That experience must be logged in the location where the flights are to take place, under the direct supervision of a qualified parasailer.
- The skipper in this case held a local launchmaster qualification and was also a helicopter pilot. His parasailing experience consisted of only 100 hours training with the operator, who was himself inexperienced. Parasailing is a specialised industry. Experience in related fields is not enough.
- The operator has since moved the winch and towing points on the parasailing boat, lowered the deck and moved the steering helm from the centre to one side. He has also purchased an adjustable chute and set a passenger weight limit, with no double adult tandems until the crew are more experienced.
- The parasailing industry, with assistance from MNZ, has been working to develop robust safety guidelines. These will be recommendatory material under the Health and Safety in Employment Act, and will include training requirements for the skipper and deckhand. Other requirements, under the Maritime Transport Act, are for skippers to have the entry-level local launch operator (LLO) qualification and for the vessel to be in safe ship management.