Issue link: https://fhpublishing.uberflip.com/i/1057016
SITE VISIT day with suitable weather conditions and the aircra operating within the four licences anywhere on WPD's network can be accessed within 30 minutes. Out of hours or when responding from Bristol an aircra can reach the furthest extend of WPD's network within one hour and 10 minutes." WPD's helicopters will normally complete five hours of flying in a day which would ac - complish approximately 60 to 100km of patrol depending on the type of network. The aircra are usually crewed with one observer and one pilot and cover 15-20km per hour on 11kV and up to 50km per hour on 132kV. "This would allow an inspection of 99.9 per cent of all the assets, therefore when comparing to the more traditional means of inspection, the helicopter is very efficient," states Tutcher. Helicopters are oen used in emergencies and the Unit has a great deal of experience in adapting to all kinds of emergency conditions. WPD's contribution has oen been a major factor in restoring electricity supplies as quickly as possible. The Unit can also provide a quick response to requests for post-fault patrols. Reports are regularly available within three hours of a request for help. Tutcher said: "The last significant snowfall (February) caused several issues both from an electrical point of view and humanitarian. The aircra were used to move people around and to assist in identifying where there were fault causing defects." Although the aerial inspection of network infrastructure usually involves the deploy - ment of piloted helicopters, drones are now becoming an alternative for getting this job done. Whilst Tutcher believes that drones do have a place he also recognises that they won't be replacing helicopters any time soon. "Drones have some way to come from a legislative and technological perspective before being able to compare to manned avia- tion," he tells Network. "Currently we also op- erate a drone which is used for very detailed inspections of singular assets primarily from a safety perspective. If the use of a drone can prevent someone from having to climb then this is always seen as a safety benefit." With technology improving all the time WPD continue to have one eye on the future with the use of LiDAR, hyperspectral imagery and data all set to play a role in the coming months and years. For now, Tutcher can't say much more, but he concludes by saying: "The range of work we undertake is changing and developing all the time. Helicopters are being used to assist with many different engineer - ing projects both in WPD's own territory and beyond." A view from above I was invited to fly in one of WPD's helicopters to experience what life is like for the pilot and observer. Now I have to admit that the last time I flew in a helicopter was above the Grand Canyon in Las Vegas. That was quite a few years ago now, but my memories of the landscape are still quite vivid. To be fair the Bristol landscape didn't disappoint, but more impressive was the skill of the pilot who was able to fly within 20 feet of the power lines that we looked at. This is when the role of the observer becomes so vital. Trained observers, using OS maps with overlays showing power lines and installations, report on 55 kinds of defects - ranging from deterioration to damage caused by storms. If the condition is urgent, details are immediately telephoned to the company's electricity network control centre. Or, if the defect presents an immediate safety risk, the aircraft would land. Towards the end of our flight one such fault was spotted and sure enough this process was followed. Between 60 and 100 km of line, depending on the voltage, can be surveyed in a normal five- hour flying day which is split into two sorties. Two men and a Land Rover would potentially take days to complete this task. WPD deliver electricity to more than 7.9 million customers over a 55,500 square kilometres service area. Perhaps most impressive of all is that the fault mentioned above would have been dealt with without a single customer even knowing about it. THE UNIT IN NUMBERS 750kg All WPD helicopters have an external lift capability of this amount. 50km The distance that can be covered by an air- craft per hour on the 132kV network. 55 The number of faults that aircraft observers are trained to look out for. 5 WPD owns and operates this number of H135 helicopters. 15-20km The distance that can be covered by a heli- copter per hour on the 11kV network. NETWORK / 22 / DECEMBER 2018 / JANUARY 2019