In late April, in the wake of a crash near Bergen, Norway involving an Airbus H225 Super Puma that killed 13 people, oil worker David Winder began a petition to remove the helicopter from service.
What began with a single signature has since become a stirring example of populist outrage that the UK Civil Aviation Authority (CAA) cannot ignore. At the time of writing, over 27,000 people, some of them relatives of those killed in other Super Puma incidents, have put their names to the petition.
Offshore safety: a top priority
As union bosses in the UK renewed calls for the government to reconsider its decision to refuse a public inquiry into offshore helicopter safety, the CAA responded by claiming that a blanket decision to remove Super Puma helicopters from active service could only be taken at the European level.
"Aircraft and helicopters are given safety clearance on a European-wide (rather than national) basis by the European Aviation Safety Agency (EASA)," the CAA said in a statement in May. "A permanent grounding of a type of helicopter would require EASA to withdraw the helicopter's overall approval, affecting all European Super Puma helicopters.
"The safety of those who rely on offshore helicopter flights is one of our top priorities and we will continue to work with the helicopter operators, the offshore industries, international regulators, unions and pilot representatives to enhance offshore safety standards still further," it added.
Jill Seymour MEP wrote to EASA executive director Patrick Ky in support of the petition asking for all versions of the Super Puma airframes to be permanently removed, a move backed by Audrey Wood, the mother of 27-year-old oil rig worker Stuart Wood who lost his life in a Super Puma crash in 2009.
"Seven years on and my life has stood still," Wood said. "Wouldn't wish this heartache on my worst enemy. All variants of Puma should be removed from the oil industry, men should feel safe travelling to work not fear if they will ever see their loved ones at home again."
Chequered history: accidents involving the Airbus Super Puma fleet
The helicopter, which costs in the region of $18m (£12.8m), involved in the latest crash was flying from Statoil's Gullfaks B platform to Bergen when it crashed near the small island of Turoey. On board were one British man, 11 Norwegians and an Italian.
Operator CHC Helicopter revealed that the Airbus EC225LP Super Puma had been forced to return to Flesland in Norway just days before the accident after a cockpit warning light came on minutes into a flight.
A part was replaced, but the warning light reappeared during a test flight the following day, after which a component was changed and a second test flight was successfully completed. CHC claims that none of the parts that were replaced was "physically connected" to the rotor or gearbox.
A preliminary report released in June by the Accident Investigation Board Norway (AIBN) said that it had found "features strongly consistent with [metal] fatigue" in parts of the aircraft's main gearbox.
The report urged European aviation safety officials to take immediate action to ensure that Super Puma H225 helicopters are safe and warned that current measures to detect faults may be inadequate.
The aircraft remains grounded in the UK and Norway, but Airbus has lifted a recommendation that flights be suspended worldwide, stating that initial evidence suggested no link with two main rotor gearbox ditchings in Scotland in 2012 involving the Super Puma H225, formerly known as the EC225.
In 2009, an accident involving a different model of Super Puma, the AS332, claimed the lives of 14 workers and two crewmen on a return flight to Aberdeen from BP's Miller oilfield in the North Sea. The tragedy was blamed on gearbox failure. Four years later, another AS332 crashed near Sumburgh Airport off Shetland, killing four people; a report published in March cited pilot error as the cause.
Examining the evidence: Step Change in Safety and public inquiry
Tragic coincidence or systemic failure? According to Step Change in Safety, the industry body set up in 1997 to improve safety on the UK Continental Shelf, eye-witness accounts and video footage from the Bergen crash suggest that the main rotorhead of the H225 detached from the fuselage. Accident investigators have ruled out pilot error and therefore the crash was likely caused by a technical fault.
Step Change on Safety also states that, based on headline safety statistics, there is no clear evidence that the Super Puma safety record is worse than other aircraft and that this is the first fatal accident involving the H225. The CAA will determine if it is safe to restart commercial flights and individual operators will then determine with their helicopter operator if and when to re-introduce the 225.
In the last decade there have been eleven reportable helicopter incidents in the UK, three of them fatal. Super Pumas are responsible for many of the 140,000 annual helicopter passenger flights in the UK.
In light of this, manufacturer Airbus and aviation safety officials in the UK and Norway cannot afford to ignore the groundswell of opinion from victims' relatives, the public, the media and worker unions demanding a public inquiry into helicopter safety with a view to removing Super Pumas from service.
In October 2014, the UK Government rejected calls for such an inquiry into helicopter safety in the UK in the wake of a report published by the House of Commons Transport Select Committee.
The government said: "We are pleased to note that the committee has found no evidence that the Super Puma helicopter is any less safe than other helicopters used in the UK offshore sector and that there is also no evidence to suggest that UK operations are any less safe than operations conducted by other states, particularly Norway, who operate under a similar safety regime in the same hostile North Sea environment.
"With regards to commercial pressure, neither the CAA, industry nor government has seen evidence to suggest that safety is being compromised as a result of commercial pressure from the industry."
Industry response: collaborative helicopter safety programmes
In 2013, the CAA announced a forensic review of offshore helicopter operations in the North Sea in collaboration with the Norwegian CAA and EASA, and advised by a panel of independent experts.
The initiative followed a comprehensive analysis of offshore helicopter reportable accidents from 1976−2012, in which the CAA established that the main causal factors were operational (pilot performance), technical (rotor and transmission failures) and environmental (lightning strikes).
The accident offshore Shetland in Au/gust 2013 prompted Britain and Ireland's largest union, Unite, to launch the 'Back Home Safe' campaign calling for various safety improvements to offshore flights.
Offshore trade association Oil & Gas UK responded by inviting Unite, the National Union of Rail, Maritime and Transport Workers (RMT) and the British Airline Pilots' Association (BALPA) to work alongside its Step Change Helicopter Safety Steering Group (HSSG) and the Helicopter Task Group.
Less than three years later, it has again taken a tragic accident to propel helicopter safety in general, and the airworthiness of the Super Puma fleet in particular, back to the top of the industry agenda.
"This petition is for all North Sea offshore oil workers and their families, and the public at large, to finally say enough is enough with the Super Puma airframe," stated David Winder.
"We call on the CAA to put the lives of offshore oil workers and the pilots before vested interests, and revoke the air worthiness certificates for this aircraft. Failure to do this we feel will result in more needless deaths."