Not only does the project cost a bomb, there are no skilled pilots in the country to take up the job, which can be extremely risky.

Almost 80 per cent of the estimated cost of Rs 8.2 crore will have to be borne by “constituents”, while the other 20 per cent will be paid by PGCIL.

The PGCIL, however, is optimistic and said the hike in the consumer’s monthly power bill will be “negligible” with this novel cleaning method. “In any case, this is a pilot project. Towards the end of this winter, we will take the details back to stockholders and discuss its feasibility. We cannot bear the entire cost on our own,” said PGCIL’s Assistant General Manager, Pankaj Kumar.

The PGCIL has paid Rs 8.2 crore to Pawan Hans Helicopters Ltd for 300 flying hours from November 2008 till March 2009. Pawan Hans has sub-contracted the work to New Zealand-based Heliwing.

“We have given the helicopter but the equipment and the skilled pilots required are being provided by Heliwing. We do not have pilots adept at carrying out such a dangerous operation. However, if PGCIL decides the deal will be permanent, we will send pilots for training to New Zealand,” said Vijay M Pathian, Deputy General Manager, Engineering, Pawan Hans Helicopters Ltd. One of the biggest advantages of this cleaning operation is that PGCIL no longer needs to shut down certain transmission towers in order to clean insulators.

“When we cleaned manually, each tower had to be shut for almost 10 hours. With this technology, helicopters spray a jet of de-mineralised water at live wires while transmission is on,” Kumar explained.

The helicopter has a long carbon-fibre water cannon attached to it, through which de-mineralised water is sprayed on the insulators. “About two metres of the cannon is made of fibre glass, which is a bad conductor of electricity. De-mineralised water too is a bad conductor,” explained Kumar. The operation requires immense skill on part of the pilot, as the chopper needs to remain stationary in mid-air, very close to high-tension live wires.