Supa-Trac makes a superb Heli-pad where ground conditions are or may become soft through heavy rainfall or snow. The use of Supa-Trac is also ideal where an emergency landing area is required. The unique impact absorbtion properties of the Supa-Trac system mean that even hard landings are safe. Supa-Trac Heli-pads are also ‘air portable’

Pilots Report

The suitability of Supa-Trac as a Landing surface for Medium/Large helicopters. The advantages of helicopters with retractable undercarriages are well known. The problem comes when landing on a soft surface such as grass after heavy rain the aircraft simply sinks in the mud. This is due to the very high ground pressure as a result of placing a large amount of weight upward of three tons in some cases on a small wheelbarrow sized tire. I was recently invited to comment on a new product manufactured by Rola-Trac Limited for its suitability as a landing surface.

The Material

The surface used was Supa-Trac provided by Rola-Trac Limited this material is made from Polypropylene providing a very strong almost unbreakable surface. It consists of 950x250 m/m sections that are light and small enough to be transported by a small commercial Vehicle or the baggage bay of a medium sized helicopter. Assembling the sections is also quick and easy; they are clipped together at the hinge points and then further secured with locking clips to prevent the surface coming apart when weight is added to it. Simply adding or taking away sections can alter size of the landing area. When the sections have been assembled tapered edging pieces are added this allows a wheel to travel over the edge safely and also provides an anchorage point for the whole surface.

Test results

Conditions on the Day: Date : July 12, 2000 Site : Grass field Temperature : + 14 c Wind : 290 at 12 kts. QFE : 1012 Rainfall : Well above average (dry on the day)

An area of Supa-Trac 9 x 30 meters was laid on the grass and secured with steel pegs at one-meter intervals along the outside edge. A Sikorsky S76A+ helicopter with a max gross weigh of 10,800 lbs. was used to make three landings to the surface with the wheel brakes applied. The surface remained almost completely stable with the exception of the area immediately around the three wheels that flexed downwards by 0.5 inches but returned to its original shape as soon as the helicopter was lifted into the hover. The adhesion of the tires to the surface was good similar to that of a road with the added advantage of having a free draining surface through small holes in the material. My other concern was that the surface might move or even lift with the rotor downwash. So the helicopter was hovered around the perimeter of the landing area. Once again the surface remained completely stable.

Conclusion

The tests carried out proved that both landing and taking off could be conducted safely. However it should be pointed out that the performance of the material is largely dependent on the underlying surface, that is to say that more flexing would probably be seen on softer ground. Although it is early days yet I feel that this product could go a long way to solving the problems associated with soft field sites.

Captain Christopher Snell