Helicopter Downdraft Dangers

on offshore installations we all deal with hazards every day of our working lives whether we are traveling to and from our place of work preparing for the day ahead or concentrating on the job in hand hazards are all around us however some are more easily recognized than others helicopter downdraft is one such hazard and it continues to be the cause of numerous incidents with the potential to cause serious injury or even worse let's look at a few examples in this incident the lid of an equipment container weighing 38.7 kilograms and a plastic storage station weighing 16 point 2 kilograms were blown from the pipe deck when a helicopter landed both items fell some eighteen point two meters narrowly avoiding two personnel working on the skid deck here a bar going approximately four kilograms slipped from a person's hand and blew off the helideck as a result of strong downdraft the bag was assumed to have fallen into the sea but actually fell some 18 meters onto containers which were fortunately in an unpopulated area here the downdraft force lifted and blue to red bags each weighing 10 kilograms from the luggage cage to a lower level where fortunately no personnel were working at the time other instances include the unsecured unlocked door of an aluminium Locker becoming detached as a result of helicopter down wash and a large container weighing 200 kilograms situated 35 metres from the center of the helideck being lifted and blown over the handrails and falling to the deck 10 metres below [Music] all these incidents had the potential to cause serious injury and occurred as a result of high-velocity ear movements caused by a helicopter in flight during approach landing or takeoff and even when stationary on the heli deck with rotors turning we were all caused by what is called helicopter downwash the vertical wind velocity directly below the aircraft and side watch the horizontal wind velocity across the surface of the ground let's take a closer look at the velocity profile created by a heavy or medium twin-engine helicopter similar to the type used for the majority of offshore travel and in this case the Sikorsky s-92 during flight the aircraft creates a side and downdraft profile this extends horizontally beyond the rotor blades and vertically below with the highest wind speeds experienced some 120 feet beneath the aircraft's rotor disk on an offshore installation rotor downwash is strongest and most dangerous when a helicopter is on short approach whilst hovering or during takeoff the site wash profile created by a helicopter on the holiday or an hover just above it is represented here wind speeds in excess of 50 knots can be experienced up to 85 feet from the aircraft which when combined with prevailing wind speed and environmental conditions can equate to the equivalent of a category one hurricane this is sufficient to move extremely heavy objects as a result the combination of both down and side wash can pose a significant hazards to personnel and plant sufficient forces can be generated to dislodge and move loose or inadequately secured items situated at distances of up to 125 feet from the helideck it's also worth noting that the actual rotor down and side wash profiles can be significantly affected by obstructions and channeling through constricted areas this when combined with the ambient wind velocity wind direction and other environmental factors can all contribute to increasing the effect of downdraft another hazard is the vertical component of the site and downdraft profile which can lift objects into the air the flight path of the aircraft is another key factor as are the size weight and rotor size of the helicopter there is also the potentially unpredictable nature of the weather other environmental factors and the structural nuances of the installation and surrounding infrastructure to consider so what can we all do to try and prevent these incidents occurring every offshore installation must have helicopter rotor downwash danger zones identified with appropriate signage at relevant locations a detailed plot plan identifying the downwash zones should be produced and consideration should be given if equipment is being cited in danger areas it is the responsibility of the HL loose and the helideck crew to ensure that all these susceptible areas not just the helideck are part of their routine checks prior to helicopter operations commencing mitigation measures must be put in place to remove store or secure all potential hazards and a toolbox talk must have occurred in advance of every flight arrival and this must include a reminder of the baggage handling procedures light objects should not be left unattended and should be secured or walked to Haley admin remember stop never chase a balloon object prevention of incidents as a result of helicopter downdraft is everyone's responsibility wherever you are working keep your work place tidy and remember good housekeeping is mandatory in downwash danger zones this is critical be especially aware of loose objects and tools not just in your work area but any adjacent areas walkways etc and remember if you're not looking and listening if you're not vigilant and cautious and aware of your surroundings then in just a moment an accident or incident can occur thanks for watching

Channel: bp

Views: 135,778

Keywords: Aviation, Helicopter, Rotary Wing, Downwash, Downdraft, Rig, Platform, Helideck, Helipad, Operations, Offshore, Safety, Awareness

Id: 09bvuYRKwwc

Length: 6min 48sec (408 seconds)

Published: Wed Mar 15 2017