Landing under HT cables

[Peter-RB]

Yesterday about lunchtime, I heard the sounds of a Helicopter obviously getting into a low and slow config,.. but when I finally saw it, to my horror it was set up in a landing slope that not only took it over many houses, but UNDER a set of 6 main HT cable with the Earth at the top of the pylons, at the point of landing the cables actually dipped lower due to the hill they were fixed to, as I was going out I deviated to go and look, by this time Heli had just departed after seemingly dropping off one pax, that must have been a very important delivery(to a building site) to take such a risk IMO.

I honestly was expecting to hear the bump followed by black smoke, I was very relieved to have seen the JHeli departing, .....but what about next time..:ugh::ugh:

[Flying Bull]

@Peter-RB -
the advantage of a helicopter is to go slow - or even hover.
Flying underneath powerlines is sometimes part of the buiseness - even so, avoided, if there is an suitable alternative.
But it´s not a big deal, if you are propperly trained.

wbr "Flying Bull"

[maddmatt]

lol reminds me when I worked in Hong Kong and we were sling loading HV Tower parts to the construction sites - these were mainly in very difficult to access areas. One issue was the pick up point for the loads - all steel components that bolt together that make up the complete tower.

At one site the flat bed truck parked very close to an existing set of HV Lines, it was the only place for it to park due to terrain limitations. We were using a Lama with a short sling to lift the steel out, with ground standing on the back of the truck to attach the stropes to the hook. Funny thing about HV lines is the rotor blades actually conduct electricity which travels all the way down to the hook!!

This is back in the days before mandatory health and safety etc, so when the first loader caught the hook and got zapped (which was funny at the time) all the ground staff refused to do the work! I was doing load mastering at the time and couldn't understand why they were all refusing to work, until I grabbed the hook on the next run!! :eek: christ almighty the jolt was fierce, so we quickly rigged a grounding rod and continued loading.

Not quite on topic but close...

[paco]

It may have been an electricity board helicopter. We did that quite often.

Phil

[WASALOADIE]

Military Helicopters practice a lot. If I remember correctly, 7 feet below, 12 feet above and 15 feet laterally is the minima. Sometimes we are forced to fly under them as flying over might expose us to enemy fire. I only ever did it once in anger in Germany so that we didn't go IMC as we climbed over the top.

[Fareastdriver]

Air traffic Control is absolutely mandatory in China. If you a cleared to somewhere below 100 metres you go under any tall power lines on the way.

[Peter-RB]

I can appreciate what you all say re the well trained Mil and poss PAS plus Ambulances will do such things along with the Elec Companies also, but the Heli was a R44, delivering some one to a private house building site, so IMO not an urgent type of thing re Pylon work or whatever or sufficient to take such a risk.... just seems crazy to moi!

[Rotor Kop]

And your point is????? Helicopters where designed to do just this and a lot more.....

[chopjock]

Drama Queen

[Bushfiva]

"Earth at the top of the pylons"

Yeah, that's not how that works. The risk is mechanical interaction with any catenary component, not "ooh plus it's electric".

[Thomas coupling]

Hi Peter,
Just to put it all in perspective:
It is illegal in the UK to fly under any wires if the flight path falls under ANO rule 5.(vehicles vessels structures persons).
There are exemptions and they are normally associated with life saving, electricity company helicopter aerial work and some mil outfits.
It is NOT the NORM and never should be.

If it was a GA helo - report him!

TC

[chopjock]

It is illegal in the UK to fly under any wires if the flight path falls under ANO rule 5.(vehicles vessels structures persons)

Unless in the process of landing or taking off of course.

[estepo]

Peter-RB, I take your point. I had an R44 pilot ask if he could land at my golf course around 10 years ago - at the time I didn't know the purpose of the flight.

I wasn't there when they departed, but a member of staff told me the owner of the helicopter and/or the private pilot who'd asked my permission, had hover taxied under high tension cables during their departure with a couple who had just got married. I immediately called the guy's mobile and it rang out. I left a message to tell him not to ask my permission to land here again.

The following morning, he returned my call from hospital. They'd subsequently clipped a tree with their tail rotor and crashed into a mountain around 10 miles from golf course. The newly married couple were both killed, along with the aircraft's owner.

He told me that he knew it was wrong to hover taxi underneath the cables, but the bride was terrified of flying, and he didn't want to argue with the owner in front of the passengers.........................

[maddmatt]

of course you don't want this to happen... zJSTyOPShOs

[SilsoeSid]

R44, wires …

Z-zI_VpTFp8

[Hot and Hi]

Nice videos! Although completely off topic ;-). The pilot who knows about the wires, and safely stays clear of them, has of course little in common with those two accident pilots who collided with a wire they didn't see.

Between the two, you tell me who is 'stupid'.

report him!

Come on, Thomas! Even if it is true that in your country some pilots are allowed, and others are not allowed to hover under a wire, what do you have to gain by reporting a fellow pilot? What is not allowed in the UK, may be (and is indeed) allowed in the next country. Arbitrary legislation here doesn't make it right, or God-given. Let's leave the reporting to the police.

[[email protected]]

Right up until someone takes the risk once too often and cocks it up, taking others with him.

Using the landing or take off excuse to get round the 500' rule in this case is just poor judgement - just pick a safer LS. The accident investigators have lots of records of people crashing in poor weather or into obstacles because they weren't prepared to walk or drive a few hundred yards.

Many people do what they think they can get away with in helicopters rather than what they should.

[nigelh]

Of course wires are dangerous if not seen ,but with proper training I don't see flying under wires as any more dangerous than landing 6 feet from a hangar . I have flown under lots of power and telephone lines doing my job and certainly never felt I was taking a risk . It's the wires you don't see that will get you . There is a very well known helicopter company that has had its bowser under wires for years !!

[HillerBee]

I don't see what the helicopter type has to do with it. We fly powerline and pipeline controls with 44's in Belgium, Germany and the Netherlands. All pilots are very experienced and well trained. The fact that R44's are used is not only the decision of the operators it is actually prescribed by the customers. So a 44 doesn't neccesarily mean it is a private helicopter with a PPL flying it.

[Peter-RB]

Well it seems most disagree with my comment , which was just that, based in the UK we are told wires Kill, and to stay well away from them, I understand all you chaps who for your living fly near ,alongside and through wires to fulfill your contracted work obligations, but taken in the context of the lie of the land in the area were I saw the R44 land, I went to look on foot, the HT cables ar at the very lowest I feel is legal for power transmission in the UK due to the terrain the R44 pilot landed in a downhill slope and took off towards trees to a height of 30/40ft within 50/75 yds of actual touchdown, ... however .750 yards away is a wide FLAT cable free field.
Some may say " And your point is" well I am only a PPL(H) but I know exactly which LZ I would have picked, if Pros feel that I am being too ultra safe in what I say and report ....then sorry but safe trumps risk( or balanced risk) anyday in my world..

Thank you TC for you comments, I was trained Never fly under or near cables, and I am still doing that..!:ok:

[maddmatt]

The point of my video was to show even well trained and skilled pilots who are aware of their surroundings make mistakes. In the EMS incident he got away with it but it just shows how quickly it can go wrong.

[[email protected]]

Peter - I do agree wholeheartedly with your comments.

There are 2 main problems with going under HT wires - the first is the risk of disorientation if you look up to check your clearances, this should have been established before you venture under them by comparing the height of the cables with the rad alt reading (if you have one, if not you are just cuffing it).

The second problem is that of arcing - when I told a relative who works for National Grid, he was horrified that we taught people to hover taxi under HT cables. The guys that work on them (not in helicopters) have to comply with stringent safety precautions - 400KVA is a sh*tload of power and, whilst you might hope that any arcing would be routed around the helicopter by the bonding of components, it wouldn't take much to get that wrong.

Pick another LS!

The thread running on 'Helicopter down near Tring' seems to indicate yet another unplanned coming together of HT cables and helicopter!

[normalbloke]

The safety clearance on a 275-400kv transmission line is 3.1 metres.

[[email protected]]

Hence wasaloadie's comments about 12 ft above. 7 ft below and 15 ft lateral clearances.

We used to use 50 ft on the radalt as a guide, if you could line up the bottom two strands and have 50 ft on the radalt, you should be able to hovertaxy under the wires at 10 ft with the appropriate safety clearance between the rotors and the cables.

[paco]

Skids on the ground for us.

Phil

[chopjock]

crab

The second problem is that of arcing

I don't think you will get any arcing with the heli in the air, it has to be grounded. A rotor blade would have to contact at least two wires at the same time in order to do that.
Birds land on them with no bother after all.

[SilsoeSid]

Chopjock;
I don't think you will get any arcing with the heli in the air, it has to be grounded. A rotor blade would have to contact at least two wires at the same time in order to do that.
Birds land on them with no bother after all.

_cx-eOUjNPE


As for them pesky birds;

mRQ2_0dgQB0

[M100S2]

Overhead line inspections at least in the UK never involve flying under the lines, alongside, at least a couple of rotor diameters away from the conductor is close enough to for the thermal imaging camera to identify hotspots.

[[email protected]]

Chopjock - back to basics school for you I think.

[chopjock]

back to basics school for you I think.

LOL. you know the difference between a static discharge and a full on KV short circuit right?

Also the first video shows a static discharge where the PD of the floating static on the heli is matched with the line, that is all. It is floating, only static, as in not earthed or connected to another phase. Notice no harmful effects to the helicopter.

[Bellrider]

Your post is totally bullsh......t

if you fly below an HT cable you'll reduce the distance between the cable and the ground. In case of an 400kv line the allowed distance is about 4 metres.
If the cables hanging quite low p.ex. In the middle of the field you really have an arcing problem, even when the heli don't touches the ground!
I'am line cowboy since 3years and belive me, never fly below HT when the distance between cable and ground is to low!

[aa777888]

What Bellrider says. And I believe the primary reason for bonding the helicopter and, more importantly, the crew's conductive suits onto the line is to eliminate the effects of the extremely high voltage gradient in the electric field strength that exists in very close proximity to the line. This gradient reaches thousands of volts/meter. It's not very survivable to have a thousand volt potential between your head and your feet. Birds get away with it because they are so small. The suit makes the voltage the same all over the body, thereby eliminating that problem. I have read that having a small "leak" or tear in a conductive suit leads to some rather unpleasant sensations ;)

And to Bellrider's original point, the guys who work on these things while they are energized have to VERY carefully respect stand-off distances to tower components. Closing the gap between a tower component and the line below that afforded by the insulators lead to Very Bad Things.

[AAKEE]

Flying underneath powerlines is sometimes part of the buiseness - even so, avoided, if there is an suitable alternative.
But it´s not a big deal, if you are propperly trained.

As Flying Bull said, it's normally not a problem and 'some' operators do this on a regular basis due to the need to stay low.


High voltage can jump 1 cm per 10.000 Volts, this is due to the conductivity of normal air. 400 KV therefore can jump 40 cm.
To add safety to this the risk area in sweden is a radius of 2.5m in air if I remember it right.


I've done a lot of flying underneath powerlines, both crossing and following under for some hundred meters. My total time underneath powerlines is measured in hours, not seconds. Never hade any problem, despite including rainy days, snowy/dusty conditions etc.

[fijdor]

There are 20,000 miles of powerline here in Quebec alone, not including the rest of Canada. That's just the 735 KV AC lines and one 450 KV DC line. Flying beside, on top or underneath a powerline is part of our everyday work. Most of the time being underneath the line (conductors) is the only place where you can land, work and park.
In my 36 years of flying and a lot of them working the lines I have never heard of a Helicopter being zapped by or electricity jumping from the conductors to a helicopter no matter what the weather was.

Bell 205 moving repair crews around the job.

JD


BSw_9bOdpOY

[albatross]

Some things never change.
Looking good!

[Bellrider]

Some things never change.
Looking good!

The stories from all guys writing here how many hours they have underneeth HT's are not interresting! I can altought tell you that i've flown 5t hours without having Vortex or Lte! But this is not the fact. Important is to know what is to do not to get into that situation.
The topic was :what is dangerous when flying in wire environment .....
Every professionell ht technican will tell you the things i told you before......
So good luck to all guys thinking today it works so it will altought works tomorrow.....

[Gomer Pylot]

You do not need to fly near high voltage lines to get electricity to the cargo hook. I've seen soldiers knocked completely off the back of 2.5T trucks when trying to hook them up to Chinooks. I've done many hours of slingloads in BH206 models, and they all create static electricity. The ground guys are taught how to dissipate the current before actually connecting the sling line to the hook.

Lots of old wives' tales on this thread, and apparently a lot of old wives, too.