what a bunch of bullocks.
Twins for power line work?!?! First of all, with either squirrel its not likely you have cat A performance at the weights and altitudes you will be working, so essentially, your "Twin" is doubling your chance for engine failure, adding a whole mess of systems combining gearboxes etc which can fail. If you can’t HOGE on one engine a twin is in many ways less safe than a single engine helicopter.
Firstly you are focusing on the wrong problem...
In the past 12 years 2000-Present in the US there have been 13 accidents and 4 fatalities doing this type of work (aerial power line work excluding patrol). I don’t have hours statistics but there are at least 26 MD500/530s doing this work full time in the US alone and several more operators that dabble.
Of the 13 accidents 3 were mechanical failures, one was a tail rotor gearbox the other two are suspected engine failures. None of the the 3 produced any serious injuries. Of the fatals, one was a fall, one was a rookie who was doing just about everything wrong, one was a 206 belly hook stringing. What were the others? Mostly blade strikes and procedural errors.
Given that your "Twin" has 3 meters more rotor blade than a 500 you've really upped that chance of that happening. You've also introduced the possibility of a FADEC or hydraulic failure where none existed before. You have gone to an aircraft with less crash survivability that seems to always burn on impact. You have dramatically decreased your downward and side visibility and now you are going to ask a pilot to string using the belly hook which is far more dangerous. And contrary to what a previous poster said, the AS350 cannot pull harder, not with the belly hook. Maybe form the side, not sure, as that’s not legal in the US.
The 500 is the bird of choice for this work for a reason. It’s the safest aircraft for the job.
The tail rotor is never a foot from the line; it is 5-10 feet from the line. If the helicopter is parallel to the line while the lineman is working off the skid the tail is 5 feet from the line. if it is crabbed even 10-15 degrees its about 8-10 feet. That is either an optical illusion or a really really really bad pilot.
Every decent operator in the world who does this work does risk assessments.
As Rick said. A lot of patrol contracts go to the lowest bidder, which is a shame. Like someone said "statistically" patrol appears more dangerous, since there have been 10 accidents and 14 fatalities in the past 10 years in the US alone. This is however, mostly due to the fact that there are non-power line savvy crews doing this work.