Flying offshore in UK? Size matters.

Step Change in Safety last week announced a size criteria for helicopter passengers travelling to and from offshore installations on the UK Continental Shelf.

Do you know what size you are? No? Read on.

Do you know your place in offshore helicopter

The criteria came in response to the size restrictions laid out by the Civil Aviation Authority (CAA) in February 2014.

Helicopter passengers will be measured by the width of their shoulders and those whose shoulder width is 22″ or greater will be classed as Extra Broad (XBR).  They will be required to sit next to a helicopter window which has a diagonal size compatible with the XBR measurement.

“25% of windows are suitable for Extra Broad passengers.”

Les Linklater, team leader for Step Change in Safety, said: “The safety of the offshore workforce is our absolute priority and we believe this measurement criteria and strategy is the safest and simplest route to take. 

“We have worked hand-in-hand with the CAA to measure the windows on every type of helicopter used in the North Sea and it is our understanding that at least 25% of windows are suitable for Extra Broad passengers. 

“Our commitment to safety will guide our ongoing discussion as to exactly how, when and where to measure the offshore workforce.”


Below is a list of frequently asked questions, with answers provided by the Step Change in Safety


1. Why are “larger” people being placed at the window seats when it prevents smaller people from getting out first?

From 1st April 2015, all passengers travelling offshore by helicopter will be required to sit in a seat where the nearest push-out emergency exit is compatible with their body size.

Passengers who are Extra Broad (XBR) will be required to sit in the seats or rows with direct access to a Type IV emergency exit or larger. This is not necessarily a window seat. The minimum diagonal on a Type IV exit is 27.75”.


2. Have the Civil Aviation Authority (CAA) agreed to the proposal and when will industry implement this change?

The CAA is a member of the Helicopter Safety Steering Group and is represented on the Passenger Size workgroup and has played a major role in developing the proposed solution. This change will come into effect from 1st April 2015 under a CAA Safety Directive.


3. The proposal does not meet the wording of the CAP 1145 recommendation – “…the CAA will prohibit helicopter operators from carrying passengers … whose body size … is incompatible with push-out window emergency exit size”.

The proposed solution meets the expectation of the CAP 1145 action A9. Evidence from our research shows that the relationship between shoulder width and the diagonal dimension of exit is the most reliable “compatibility” test. Bi-deltoid (shoulder) width is relatively easy to measure and has built-in conservatism as people tend to exit with a leading hand / arm (‘Superman’) position.


4. Why will passengers be measured by their shoulders and not the size of their stomach?

A person’s shoulders are solid and inflexible, whereas the stomach is soft and compressible. Shoulder width is governed by our skeletal frame, our bone structure.


5. What will happen to XBR passengers?

XBR passengers will be required to wear an armband similar to the green armband we use for new-starts. They will be directed to suitable and easily identifiable seats by ground crew and helideck crew.

Changes will be made to Vantage to allow this to be managed effectively during flight planning and prevent excessive delays at the heliport.


6. What about the other passengers?

Other passengers will be able to sit where they want to, or will be directed to specific seats by the ground crew, helideck crew or pilots exactly as they are now.


7. How many XBR passengers can sit in a helicopter?

Different helicopters have different seating configurations and the number of seats per airframe and seating configuration has been agreed with CAA. The CAA have advised that the minimum number of seats suitable for those categorised as XBR is 31.5% and most aircraft have more than this.


8. How, when and where will helicopter passengers be measured, and who will measure them?

This is still to be decided but there are a number of options to consider, such as using the approach we took with CA-EBS. We are also looking at the practicalities of using the offshore medics and measuring passengers during their routine offshore medical.

Passengers’ measurements will then be recorded in Vantage.


9. Is this unfair on the people who are not XBR?

No. This approach ensures that everyone on the aircraft will sit in a seat row where the nearest push-out emergency exit is compatible with their body size.


10. Has the bulky EBS lifejacket, bottle and hose been included in the study and calculations?

Yes. Passengers tend to leave a window in a ‘Superman’ position which reduces their shoulder width, allowing room for the survival equipment. In the CA-EBS approval process, test subjects covering a representative range of body sizes successfully exited through a 17” x 14” window with their survival suit and CA-EBS on.


11. In an emergency event will these regulations apply?

As stated in CAP 1145 these regulations will not apply in the event of an offshore emergency.


12. Why can’t the size of helicopter windows be changed?

The windows are part of the helicopter airframe and as such they can’t be changed without impacting on the structural integrity of the helicopter. The research indicates that our current helicopter fleet will still be able to carry all those travelling offshore today.


13. What consideration is being given to helicopter re-design?

New aircraft are being introduced into the industry on a regular basis and the latest designs have been developed in consultation with those operating in an offshore oil and gas environment. We are aware that the new designs do take into account passenger size.

In addition, the European Aviation Safety Authority (EASA) is currently reviewing the regulations relating to ditching and survivability. The CAA is playing a major role in that exercise.


14. Is the industry pushing this issue too quickly to maintain seating levels on helicopters?

No. Step Change in Safety, as a tripartite body, has worked to come up with a safe and practical solution that ensures all passengers sit near an exit that is compatible with their body size. None of the parties involved are under any pressure to maintain seating levels.

With some 60,000 offshore travellers in a year, a core workforce of about 27,000, 90 aircraft with 20 different windows the complexity of understanding this issue has meant that we’ve taken six months to develop the proposed solution. We worked with Oil & Gas UK and RGU to expedite their study on size and shape as we wanted to have the very best data available to base our decisions on and as much time as possible before 1st April 2015 to implement safely and effectively.


15. Will this size restriction be included in our HUET survival training?
The review of BOSIET and FOET which includes HUET is about to commence and will be completed in the first quarter of 2015. HUET, as part of the OPITO standard, is a training exercise and as such is designed to build knowledge and skills around how to make an effective underwater escape. Exit types and sizes is something that will be considered as part of the review.


16. Have goggles been considered to improve vision in an immersion? These are in use, in the Canadian offshore industry, and appear to be a way of improving prospects of successful escape? It is our understanding that they do currently use goggles in Canada but they are in the process of removing them.

The new EBS was specifically introduced to improve the speed of deployment and permit underwater deployment in the event of a water impact. While there may be some benefits in terms of visibility, the added complexity of having to put on goggles in an emergency situation is likely to outweigh these. In addition, goggles would have to be deployed before submersion to be effective.


The original version of the above post can be read at the Step Change in Safety website. One can also download a PDF document of the Frequently Asked Questions related to the Passengers Size issue.


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