Powerline maintenance helicopters

[skridlov]

Non pilot here.
Yesterday Discovery Channel (as best I recall) showed a program about powerline maintenance in the USA. This program included hair raising material showing the use of helicopters to convey maintenance technicians into place - actually working off the skids on lines at 500Kvolts. At some points the tail rotor appeared to be about a foot from the lines. The whole rig is attached to the live line by a cable during the maintenance after initial connection via a wildly arcing wand...

During the course of the program the crew being filmed were actually called to a site where a previous 2-man crew (pilot & technician) had just been killed in the course of the same work.

Next to bomb disposal, this takes my prize for br@55 b@ll5. Anyone here actually done it? And wouldn't it be better to use a helicopter with a shielded/enclosed tail rotor?

Phew, rispeck!

[jab]

The Hughes 500 is just the best machine for the job despite the tail rotor being on the line side. If done correctly, the tail rotor should not get closer than about 5 feet from the line at any time. A fenestron would be nice but the EC120 is underpowered for this job and everything else is just too expensive. Bell 206 series helicopters do work well and the tail rotor is farther away from the line but then you have longer and higher main rotor blades when working between the earth / shield wire and the conductors so less clearance, the 500 is better.

The crash they went to was of a helicopter involved in powerline patrol that flew into wires, not the same company or same work and just coincidence that it happened at that time, sad though it was.

Overall, the work is challenging, rewarding and some of the best flying I have ever done.

[Gordy]

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Do not do live line repair--but have many hours patrolling for WAPA:

http://i76.photobucket.com/albums/j35/helokat/Layla/2.jpg

[UKpaxman]

I just watched the documentary on Discovery this afternoon. I think they're all certifiable - bad enough sitting on the heli skids while working on live 500,000 volt powerlines but water washing the live insulators from the helicopter is :eek:

Absolute nutters, no risk assessment I've ever seen would let them do what they were doing.

[Gordy]

Absolute nutters, no risk assessment I've ever seen would let them do what they were doing.

There is a risk assessment, it is a job, and the risk is mitigated for that particular job. I have not done live drops of people, but do sling them tools after they have climbed up, and have also set poles... There is always a tail gate brief and all aspects of the job are discussed. This is all in a days work for some, and I guess it comes down to what you feel comfortable with.

[UKpaxman]

Does anyone in the UK powerwash live 500,000 volt insulators using a helicopter?

[west lakes]

Paxman

Does anyone in the UK powerwash live 500,000 volt insulators using a helicopter? Nope because: -
1/ our maximum transmission voltage is 400,000 volts

But more seriously

2/ the only live line operations approved, by any means, in the UK are at up to 11,000 volts from insulated "cherry pickers"

Helicopters are used for line patrol and load lifting in dead line situations

[MightyGem]

Ppruner AirWon does this for a living and was one of the pilots in the programme.

[AirWon]

So let me get this right, water and electricity don't play well together? I knew that tingly feeling wasn't just me arthritis playing up again.....

[UKpaxman]

Hats off to Airwon, there's something in my brains logic that says you just shouldn't mix water and electricity.

From the programme it was clear that Air2 take the safety of their ops very seriously but it's interesting that the UK and US seem to have different interpretations of what's allowed on live o/h lines.

I wonder if in the UK they're allowed to powerwash live 11kv insulators from the cherry pickers? I'd be surprised.

[west lakes]

So let me get this right, water and electricity don't play well together

Well the company I work for is also the water utility & we get on alright!

I do recall that insulator pressure washing has been done in the UK at ground level, if the conditions are controlled (especially the water quality) it is not difficult.
From a helicopter as there is no connection or contact to earth the risks (electrically) are far lower, any electrical charge picked up by the machine is not a problem as the whole machine would be live at the same voltage.

(just as birds sat on powerlines don't get fried - same principle)

[Senior Pilot]

There are two previous threads on this, complete with videos, worth looking at:

I don't give 2 hoots and a holler about flying inside a helicopter (http://www.pprune.org/rotorheads/273422-i-dont-give-2-hoots-holler-about-flying-inside-helicopter.html#post3252581)

Danger Men: UK TV Channel 5 (http://www.pprune.org/rotorheads/346643-danger-men-uk-tv-channel-5-a.html)

:ok:

[Girv]

The water used for insulator washing is demineralized. Demin water prevents conductivity so does the wash boom. At no time does the aircraft become energised when washing insulators.
Live line platform work and insulator washing is very safe as long as you follow the procedures that are in place for such operations.

[Fark'n'ell]

So let me get this right, water and electricity don't play well together? I knew that tingly feeling wasn't just me arthritis playing up again.....

Pure water does not conduct electricity.I beleive Faraday used demin water as a dielectric in some of the capacitors he made.Could be wrong though (about Faraday) but thats what we were taught in physics 45 years ago.

[Mark Six]

The water used for insulator washing doesn't have to be demineralized, the conductivity just has to be below a certain level. Tap water is often suitable. There is a risk of the current passing through the helicopter (and occupants) if the gap between the conductor (wire), the aircraft and the ground (or tree), or between the aircraft and 2 conductors isn't sufficient. The spark will jump the gap, pass through the helicopter and jump to the earth or other wire. An Aussie machine got zapped a couple of years ago. Linesman knocked unconscious, pilot injured and aircraft damaged. A linesman in Australia was killed a few months ago doing live line work when the aircraft M/R clipped a wire.

[500 Fan]

Just a couple of questions in relation to the use of the MD500 in line maintenance work.

1. Is there any other type that can replace the MD500 in the line maintenance role, particularly in the use of the mainteance platform for the line-man?

2. Will Haverfield/Agrotors simply replace their older 500Ds with new-build 500Es?

3. The dominant version of the 500 used in line-maintenance work seems to be the D model , with a handful of E models thrown into the mix. Is there an reason why the MD530FF is not being used for this type of work?

4. If the 500D was still in production, would it sell better than the 500E to operators like Haverfield and Agrotors for such specialised work?

Thanks.

500 Fan.

[Heli-phile]

The 500 series is a great machine due to it small MR disc dimension, excellent visibility for pilot and sensitive (but not over sensitive) control. It also has a relatively short tailboom and thus not as prone to momentary weathercocking with wind gusts.
This makes it a very stable platform for this type of work, as for using a E model or indeed an F model there is no benefit, with the kind of payload used in this role neither a more powerful engine or indeed as in the f model a beefed up main transmission is of any use.
For line work the D model is fine and it's lower fuel consumption gives a much better loiter time and lower running costs.

[Pilot DAR]

Absolute nutters, no risk assessment I've ever seen would let them do what they were doing.How appropriate it must be then that you are not associated with that operation!

[kulchashock]

Skywork in New Zealand use B3's. Would be interesting to hear how this machine compares to the MD's? Simplex in the US have also been trialling a wash-rig on a Bell407...so the MD's aren't the only viable options.

KS

[Heli-phile]

Spray washing, -
probably easier in a AS350 - higher load capaicity,bigger tank, longer loiter.

Line man work -
H500 for reasons below.

[Girv]

The D and E model are the same pretty much except that I prefer the D model instrument panel. The company I work for use C20r2 engines in both types. We still have c20b's in three D's which are ok for certain platform jobs and patrolling. When it comes to washing though they struggle as we wash during summer. We have an F model that is being rebuilt which was purchased for stringing but I personally think that an AS350 would of been better purchase as they can pull more.

[donnybrook]

pretty quiet 500! or loud tools....

[freerideroj2]

only live line work in UK is grid on their 400kv lines, not sure how much they do (in their N's) We do everything from 11-132,000. Insulator spraying was an idea at one point, infact i think we had a demo but didn't catch on. Cleans muck off that degrades or shorts out lines - potentially.

[wheatbix]

I'm looking around to see if anyone has any sort of online material (PDFs, word docs, websites etc) that provide information on conduct, procedures and advice in regards to powerline operations and inspections.

If you've got something or anything at all i'd be greatly appreciative.

Thanks very much!

[paco]

There's a short section in The Helicopter Pilot's Handbook (http://www.electrocution.com/aviation/#HPH). I have some ops manual-type stuff if you want to PM me.

Phil

[fly911]

Bird on a wire.

16TJNgUQdeM

[Gordy]

same same...

PG & E live wire work (http://abclocal.go.com/kgo/story?section=news/assignment_7&id=7291774)

[rick1128]

I talked with a pilot who does fly a 500 for one of the US companies that does this work. As far as he was concerned, powerline patrol was more dangerous than what he does. This was confirmed at the Last Heliexpo where I talked with several management pilots and linemen for companies like Winco, Wilco Construction, Haverfield, Bonneville, etc. Everyone of these companies have a very strict SAFETY FIRST policy. Nothing happens very fast. The procedures are set in granite, not just stone. Things like the above course and other required training programs. Most of the powerline patrols are run done by contractors who were the lowest bidder, so they tend to push speed and get it done NOW. And you can see the results.

Of course none of this is as much fun or as interesting as running the powerline saw. Yee Haw!

As for wire pulling, forget the Squirrel. Go with a Lama and go big early.

[Gordy]

rick1128

There have not seen too many accidents while conducting power work that I have seen.

Most of the powerline patrols are run done by contractors who were the lowest bidder,

Not on the west coast...certainly California is dominated by PG & E, SDGE, WAPA, and LADWP. All who either have their own helicopters or contract with certain approved vendors.

On an interesting note, for the last 18 months, WAPA has been putting their power line work out to bid amongst the approved vendors only. (WAPA is Western Area Power Administration, which is sister company to Bonneville Power, both are divisions of the US Department of Energy).

[AW139 Engineer]

Back in the 1990's I was working with Vancouver Helicopters that used the Bell 206 and 206L the fly the inspection / repair crews of the provincial power authority and drop them on & off the top of powerline towers. I designed and certified a static grounding device that has now been adopted as a requirement by the local power companies performing similar work.
What it did was it equalized the static differential between the top of the tower and the helicopter as it touched down on top of the tower frame, thus reducing the static shock hazard when the tower inspectors stepped out of the 206 and contacted the tower as they hooked up there safety belts to the tower.

There was always the worry that if a worker got a severe static shock it may incapacitate his ability to get his safety belt connected and he may fall while dis embarking the helicopter.

It is a rather simple device and can be locally manufactured. If your company is seriously considering landing on towers I would recommend it.
I am not interested in building more of them as there is no money in building and certifying anything these days unless your making a large quanity of them and charge large $$$$. I no longer have the time the build mods any more.

If your serious about it pm me. I will forward a sketch to any legitimate company, please though no wanna be's

[rick1128]

Gordy

That used to be the case in much of the US. However east of the Rockies it seems that as these power companies merge, they are letting more of these patrol functions out for bid. And the bidding process is run by accountants. Hopefully that might change by as long as the accountants run things it will not.

I did backup pilot work for one power company, that is not just a small part of a larger power company. The patrol people were part of the corporate flight department. They had a flexible schedule that allowed them to vary the patrol schedule to account for weather and company needs. They were also allowed to explore areas near the lines to check on things like construction or other work they felt might endanger the lines.

[Phil77]

Rick:
PSE&G in your neck of the woods operate their own MD500 (including the life line work). Not saying that that holds true for PP&L and others in the area though.

[fling-wing_1]

500 Fan,

The D model is preferred due to lower weight, smaller instrument panel (better visibility.)

The 530FF generally is too expensive for the advantage it offers. A 500D with an R engine would be a much better alternative.

Companies such as Haverfield, Air 2, etc. generally make due with what they have. Fleets are a mix of D's and E's usually due to what is available for the right price when a company is in the market to expand the fleet.

MD was talking a few years ago about building a G model. Essentially an E model express built for the utility market. Don't know what happened to that idea. What they need is a light D model with a cut down instrument panel like the old 269A IMHO. Maybe with a nice digital engine display package. Then again maybe not as that might cut down on the pilot's "finessing" the most out of the old girl. :rolleyes: I don't know, Tilton doesn't seem to recognize the unique mission role of the 500 and the fact that there really isn't anything out there that can replace it in many applications (powerline maintenance being one.) Then again, she also seemed oblivious to the fact that military folks, hard partying aside are quite conservative by nature and might be put off by someone who brags openly about using sexuality to get what she wants in the business world :confused: Not to say i don't like her. She seems quite bright but oblivious to the potential captive market right in front of her. :ugh:

[Steps off soapbox :} ]

[rick1128]

Many of these powerline companies do modify their helicopters for this mission. Of the few I have looked at the companies rotate the torque gauge 90 degrees for easier viewing. Also they usually put a set of warning lights, that are bootstrapped from the annunciator panel, either where the front left door frame meets the floor, just inside the door frame on the floor or just outside the door. Allowing the pilot to really concentrate on the job at hand. Too bad they are not offered by MD as options.

[desertsnake1991]

I ran across this old thread doing some research, thought I'd toss a few nuggets out there. I just did a short tour doing this nutty job with AIR2 and we used an extremely, sparsely (dangerously so) equipped 80's model MD 500. NO gyro, a 13 yr old mickey mouse gps, an ancient radio, no AI, and just a wobbly standby compass to navigate with . It was a trip flying this stripped old 500 after just having done a combat tour in HH-60L model Blackhawks! I'm headed back to DurkaDurkastan soon IP'ING Mi-17's , but will prolly. ome back to doing aerial line maintenance work (although with a safer/better outfit) as it pays WAY better than EMS work . MD's are simply the preferred bird for this kind of work, stable and safer in a crash scenario. All the way !

[Heli_Fella]

In the UK the Grid network is done using twins. I believe company owned AS 355 N & NP as seen at Sherburn.

As for Live line work they have adopted the french method (except the Chinooks) as per video link ;-)

Live line the English way - YouTube

[500guy]

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.

[Hughes500]

Couple of years ago UK National Grid asked me to look at live line and patrol stuff with 500's. basically was told by their flight department the 500 was crap. 355N was better and safer hanging a basket with 2 guys 100 to 150 ft under the helicopter ! Now forgive me here as I have never done live wire work ( would have had to buy in expertise ) but certainly have done long line work, how is it safer using a 355 with no floor window hanging a basket 150 ft below? Personally I think that would blow a risk assessment out the window !!! I have heard that there were not many volunteers for the basket and the 355 could only carry 20 mins of fuel to stay cat a - what a waste of money, mind you if you see what happens at Nat Grid it is par for the course