Norwegian Survival Suits: Suited for Safety
The Norwegian Petroleum Safety Agency (PSA), has published a piece on the history of survival suits in Norway in their latest Dialogue magazine.
Amusingly their first illustration highlights a hazard unique to early survival suits that we discussed after the 2014 Oil & Gas UK annual aviation seminar, namely cigarette burns, as smoking was still allowed!
The article primarily concentrates on developments by Hansen Protection, including the development of the Sea-Air Barents suit, which can be fitted with a compressed air Sea-Air EBS (Emergency Breathing System):
Sea-Air Barents Survival Suit (Credit: Hansen Protection)
The material of the suit includes tiny capsules filled with microscopic particles of a paraffin wax specially developed by SINTEF. When the wearer’s skin temperature rises above 28ºC, the wax absorbs the body heat and changes from solid to liquid. The latent heat help keeps the wearer is cool in the helicopter cabin on warm days. When immersed in water, he wax releases the stored heat to the wearer as it returns to the solid state. Hansen Protection claim this ensures the wearer’s skin temperature never falls below 15ºC during six hours in a water temperature of about 2ºC.
The suit will be used in operations to support the ENI Norge Goliat FPSO in the Barents Sea from Hammerfest.
Another article in that issue discusses a collaboration to overcome the challenges of operating in the Barents Sea. Aerossurance has provided aviation support to two of the 16 companies involved in that effort.
Survival suits are an area currently being examined as part of the European Aviation Safety Agency (EASA) Rule Making Team RMT.0120 that is working on enhancements to helicopter ditching and survivability. A Notice of Proposed Amendment (NPA) is due around the end of 2015.
Aerossurance has previously discussed new helicopter survival suits being introduced in Canada, the standardisation of clothing policy in the UK and the introduction of Category A Compressed Air – Emergency Breather System (CA-EBS) the UK. The later two follow the publication of UK Civil Aviation Authority (CAA) ‘Safety Review of Offshore Public Transport Helicopter Operations in Support of the Exploitation of Oil and Gas’ (CAP1145).
The article discusses the loss of the floatel Alexander Kielland in 1980 and three helicopter accidents:
- 9 July 1973 Sikorsky S-61N LN-OQA: Ditched and capsized after loss of tail rotor (4 fatalities, all post impact) – note the PSA incorrectly state this happened in June 1973
- 23 November 1977 Sikorsky S-61N LN-OSZ: Impacted the water after a main rotor damper failure (12 fatalities including one person who did reportedly escape the aircraft alive)
- 26 June 1978 Sikorsky S-61N LN-OQS: Impacted the water after a main rotor spindle failure (18 fatalities)
All three aircraft were operated by Helikopter Service.
The choice of helicopter accidents is interesting. In the first case survival suits would have been a definite advantage. The second case appears to have been a survivable water impact and so a survival suit would have been beneficial to the person who exited the aircraft and may have helped others. In the third accident (with over half of the fatalities), the loss of a main rotor blade in flight would have been non-survivable and so survival suits would have been irrelevant.
While operating without survival suits over a hostile sea is inconceivable today, the above accidents also illustrate the inappropriateness of trying to justifying safety improvements on past accidents where the improvement would have had no effect.
UPDATE 24 January 2016: CAP1145 Helicopter Water Impact Survivability Statistics – A Critique: we reveal a surprisingly misleading inconsistency in a formal safety study.