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-   -   Tennessee Crash of Bell 206B / Jet Ranger (https://www.pprune.org/rotorheads/648518-tennessee-crash-bell-206b-jet-ranger.html)

SASless 24th Aug 2022 11:28

Tennessee Crash of Bell 206B / Jet Ranger
 
Fatal Crash near Sevierville, Tennessee involving a State Trooper and a County Sheriff.

Original reports said it was a R-22 but later reports said it is a Bell 206

It appears to be a wire strike that resulted in the death of both occupants.

https://www.timesfreepress.com/news/...bBaKbndITyv9eQ

treadigraph 24th Aug 2022 11:36

Definitely a 206 apparently:

https://aviation-safety.net/wikibase/281925

[email protected] 24th Aug 2022 11:58

Another sad loss of guys just doing their jobs - helicopters and wires don't mix well. RIP

megan 24th Aug 2022 19:42

Does anyone have experience with the power line detectors that can be fitted to the aircraft, any good?

helispotter 25th Aug 2022 05:44

Megan: Your post got me curious. I found this video on YouTube: "Heli-Expo 2015: Safe Flight Powerline Detection System" [ link is at https: // www . youtube . com / watch?v = CxsR_aA5XN8 ...once you remove the spaces]. Is that what you had in mind? I wonder if this works mainly for high tension power lines, or also simple spur lines that might have just a single wire of modest voltage?

Then again, there is also always Wire Strike Protection System if that counts as a way of detecting wires!

ShyTorque 25th Aug 2022 06:14

In the RAF we flew a trial in 1980 using helicopters fitted with a cable detection system. The cockpit had a round gauge with a “daisy” type display. It was supposed to alarm and the appropriate “petal” would indicate the relative direction of the cable.

It didn’t work well and it never appeared as an aircraft modification.

OvertHawk 25th Aug 2022 08:35

The system I have recent experience of is at best unreliable and at worst downright useless and distracting.

Its ability to detect even the largest 275kv pylon lines is random. I'd say it alerts to less than 50% of what it's supposed to and there is no particular pattern to which ones it will and will not alert. It also regularly generates false warnings.

Plus the system itself spends more time unserviceable than serviceable.

This particular system is negligibly effective in terms of wire strike prevention and almost certainly counter productive to safety in the wider sense (especially when you consider that the antennae regularly fall off the machine!).

Other better systems may be available.

hargreaves99 25th Aug 2022 09:05


MechEngr 25th Aug 2022 14:48

Data storage is cheap and most power lines aren't going anywhere - they are thin enough that one could approximate them as points where the towers are and line segments between the points; for multiple parallel lines, use the middle and set a width value. Add in a GPS receiver and one could have an avoidance system for the electrical wires; also guy wires and radio/tv/water towers as well.

It's not typical that the locations of these wires or towers changes rapidly, but I would expect a subscription service could pay for keeping the map updated. This would work whether the lines were energized or not, lighted or not.

There appear to be about 700k miles of main transmission line, estimate roughly 10 towers per mile, that's 7 million points/line segments. say 24 bytes for lat, long, alt, and 4 for width - that's 200 MBytes and covers within a couple of meters for the entire continental US. Make that 10 times that for secondary lines and guy wires, et al, and it's 2 GBytes.

A 128GByte USB stick is $14, so there's room for other features/higher definition at that price.

Other sources say only 200K miles main but 5.5M miles secondary, which is lower than my estimate. So it's doable by a wide margin.

RatherBeFlying 25th Aug 2022 15:41

Flarm Obstacle Warning System

Flarm began as a traffic warning system.

Popular in EU GA and gliders in NA, OZ and NZ.

ShyTorque 25th Aug 2022 15:44


Originally Posted by OvertHawk (Post 11284825)
The system I have recent experience of is at best unreliable and at worst downright useless and distracting.

Its ability to detect even the largest 275kv pylon lines is random. I'd say it alerts to less than 50% of what it's supposed to and there is no particular pattern to which ones it will and will not alert. It also regularly generates false warnings.

Plus the system itself spends more time unserviceable than serviceable.

This particular system is negligibly effective in terms of wire strike prevention and almost certainly counter productive to safety in the wider sense (especially when you consider that the antennae regularly fall off the machine!).

Other better systems may be available.

Sounds like your experience was the same as ours!

Gordy 25th Aug 2022 17:11


Originally Posted by MechEngr (Post 11285070)
There appear to be about 700k miles of main transmission line, estimate roughly 10 towers per mile, that's 7 million points/line segments. say 24 bytes for lat, long, alt, and 4 for width - that's 200 MBytes and covers within a couple of meters for the entire continental US. Make that 10 times that for secondary lines and guy wires, et al, and it's 2 GBytes.

500kv lines have about 7 structures per mile, however, when you get to the lower voltage transmission circuits, 65kv lets say, there will be 20-30 poles per mile. And then there is distribution circuits, best estimate is about 5-6 million miles. Then add the service lines that go to buildings and you double that.

In reality, there are very few power-line structures above 300 ft AGL. A standard 500kv transmission tower structure is below 200'. Valleys are another matter---if there is a crossing over a valley, the structures on either side will be below 300' agl.

My advice, unless you need to be down there, stay above it.

[email protected] 25th Aug 2022 21:46

In the UK, the Ordnance Survey produces an overlay of power lines, large and small, on 1:250,000 and 1:50,000 maps - there is also a digital database showing all the wires and most masts and wind turbines.. Apps like sky demon and Runway HD will warn of wires.

EMS R22 26th Aug 2022 09:09


Originally Posted by megan (Post 11284549)
Does anyone have experience with the power line detectors that can be fitted to the aircraft, any good?

Yes, I have flown through wires with a H500 and the wire strike kit did it’s job. Hardly a scratch on the machine.

Saved my life.

212man 26th Aug 2022 12:04


Originally Posted by EMS R22 (Post 11285474)
Yes, I have flown through wires with a H500 and the wire strike kit did it’s job. Hardly a scratch on the machine.

Saved my life.

Megan asked about the power line detector kits, not wire strike kits.

SASless 26th Aug 2022 14:05

If you need the Wire Cutters.....that is a bit late on detecting the wires.:ugh:

Hot and Hi 26th Aug 2022 15:51

I am often surprised that see that a little bit of irony is missed by many of us.

charliegolf 26th Aug 2022 21:31


Originally Posted by [email protected] (Post 11285262)
In the UK, the Ordnance Survey produces an overlay of power lines, large and small, on 1:250,000 and 1:50,000 maps - there is also a digital database showing all the wires and most masts and wind turbines.. Apps like sky demon and Runway HD will warn of wires.

Back in the last C, we would spend ages over-marking the lines you mention Crab, 'cos they weren't too easy to see, especially at night.

Shy: did we have a master wires map in planning, for the ones that missed the print?

I remember the wire indicator- by your right knee?

CG

[email protected] 27th Aug 2022 06:37

CG

Back in the last C, we would spend ages over-marking the lines you mention Crab, 'cos they weren't too easy to see, especially at night.
Yes, I did rather a lot of that myself :ok:

ShyTorque 27th Aug 2022 07:21


Originally Posted by charliegolf (Post 11285818)
Back in the last C, we would spend ages over-marking the lines you mention Crab, 'cos they weren't too easy to see, especially at night.

Shy: did we have a master wires map in planning, for the ones that missed the print?

I remember the wire indicator- by your right knee?

CG

There was a master map in flight planning at Odiham; it also had “local avoids” on there. I can’t remember if there was one at Gutersloh.


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