Serious questions surrounding the crash last August of a Super Puma helicopter into the sea near Shetland, resulting in the deaths of four workers, as well as previous tragedies have come to light.

Britain’s parliamentary transport select committee has launched an investigation into the crash, holding its first hearing last month in Aberdeen to take evidence from representatives of the oil industry, helicopter operators and the trade unions. A long-delayed fatal accident inquiry into the crash of a Super Puma into the sea off the coast of Peterhead in 2009, killing all 16 on board, has also finally begun.

Even as both proceedings got underway, another potential disaster was narrowly averted. A Super Puma AS332 L2 aircraft, the same model involved in both fatal crashes, provoked an all-out emergency at Sumburgh airport in Shetland when it reported problems around 50 miles offshore on January 29. An escort helicopter accompanied the aircraft to the airport after a warning light came on in the cockpit.

The parliamentary investigation into last August’s crash convened just two days earlier. Union officials told the hearing they had received hundreds of letters from workers in the wake of the disaster raising concerns about the helicopters. John Taylor of Unite stated that he believed commercial pressures to cut costs were impacting the helicopter companies. “The fact of the matter is that helicopters keep falling out of the sky and crashing in the UK sector. The fact of the matter is that the UK workforce wishes to find out why that is happening,” he stated.

He went on to note that many of the letters received by the union explained the fear felt by workers about speaking up over safety concerns, lest they lose their jobs.

Earlier last month, the Air Accident Investigation Branch (AAIB) produced its latest special bulletin on the Sumburgh crash. It concluded that helicopter operators have consistently failed to provide appropriate safety briefings on the use of breathing equipment available to all on board, with the result that workers may not be aware that the emergency apparatus can still work when submerged under water even if it has not been activated beforehand.

This is a damning revelation in light of what is known about last August's crash and helicopter transportation at sea in general. Had such procedures been followed, the likelihood is that there would have been fewer fatalities. Seconds after hitting the water, the helicopter capsized and the cabin filled with water. The additional time which the breathing apparatus would have provided may have enabled others to successfully escape the wreckage.

Moreover, the behaviour of the helicopter after striking the water was by no means surprising. Research has indicated that in 60 percent of all helicopter ditchings the machine capsizes and takes on water. Nonetheless, the AAIB noted in its latest briefing that there is not even a regulatory requirement on the helicopter operators to provide emergency breathing systems, let alone inform passengers about how they should be used.

Colin Milne, of the pilots union BALPA, called for a judicial review at the hearing into the regulation of the helicopter operators in the offshore oil and gas industries. He urged the Civil Aviation Authority to be granted strengthened powers to enforce higher standards of practice.

The CAA gave the go-ahead for the model of Super Puma aircraft involved in the crash last August to resume flying barely a week after the event, at a time when no confirmation as to the reason for the ditching of the helicopter had been obtained. In so doing, the CAA directly contradicted AAIB statements that investigations were still ongoing.

The statements of the union officials at the hearing were just as damaging for the trade unions as the companies involved. Through the helicopter safety steering group (HSSG), the unions cooperate closely with the companies to suppress workers’ concerns and boost confidence in the safety record of the Super Puma.

Workers have clearly expressed their lack of confidence in the aircraft. A Facebook page entitled “destroy the Super Pumas” received backing from over 38,000 people. A planned protest in Aberdeen last September was called off by the unions at the last minute.

The HSSG supported the resumption of Super Puma flights immediately after last August’s crash. When the AAIB report appeared in January criticising the inadequacy of pre-flight safety briefings, the HSSG issued a pro forma statement declaring that these would be altered accordingly. The unions made no criticisms of the helicopter operators on this point.

Evidence emerging from the fatal accident inquiry into the 2009 crash points to poorly organised maintenance of aircraft, repeated problems with gear box failures on Super Pumas, and a lack of resources for safety inspections.

During the week prior to the April 1 crash, engineers on the Bond helicopter located a metal particle on the gearbox, which, according to evidence from experts, could either have pointed to the beginnings of the breakup of the structure or the introduction of a “foreign object” which could have produced damage. The crash was ultimately caused by cracking on the gearbox shaft which resulted in the disintegration of the gearbox and the pilot losing all control of the helicopter.

The helicopter’s Health Usage and Monitoring System (HUMS) detected multiple chips in the epicyclic module on both 24 and 25 March, and on the day of the crash itself, four more chips were recorded on the system.

According to the helicopter’s safety log, checks completed on the Super Puma the day before it crashed were carried out in 10 minutes, between 09:30 and 09:40. After being questioned by a solicitor representing the families of the victims as to the short period of time taken for safety inspections, the only explanation offered by director of engineering at Bond, James Gilmore, was to claim that the records were incorrect. “There is an anomaly there, I think. Ten minutes seems very tight,” he commented. He denied that the rushed inspection had anything to do with low staff numbers, following a remark from solicitor Tom Marshall that “four men looking after eight helicopters seems quite a low number.”

In spite of the mounting evidence of systemic disregard for the safety of oil workers by the industry, the political establishment is united behind the call for further deregulation. Less than a month prior to the crash off Shetland last August, the Scottish National Party, which leads the regional administration in Edinburgh, announced its plan to establish an oil industry commission if voters back independence in the referendum later this year.

The plan would give the major companies direct channels to consult with government ministers, and in turn the government would give the corporations advanced notice of any new regulatory proposals. They have also pledged to implement a low-tax regime.

Having announced new tax breaks for the industry, the UK government is preparing to explore the possibility of implementing legislation to encourage oil companies to rationalise their operations through collaboration on infrastructure and facilities. Aimed at extracting additional oil revenue from the North Sea, such measures will only intensify the already substantial competitive pressures to cut costs.

As Graham Sadler, head of the Petroleum Services Group at consultancy firm Deloitte, commented, “Despite the high oil price, margins are tight and the drop in drilling during 2013 most likely reflects the increased costs of operating. Staff costs remain high and access to equipment such as rigs, which are limited in number, drives prices upwards.