Tennessee Crash of Bell 206B / Jet Ranger
Thread Starter
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
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
Last edited by SASless; 24th Aug 2022 at 11:39.
Gnome de PPRuNe
Join Date: Jan 2002
Location: Too close to Croydon for comfort
Age: 60
Posts: 12,664
Received 321 Likes
on
178 Posts
Another sad loss of guys just doing their jobs - helicopters and wires don't mix well. RIP
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!
Then again, there is also always Wire Strike Protection System if that counts as a way of detecting wires!
Avoid imitations
Join Date: Nov 2000
Location: Wandering the FIR and cyberspace often at highly unsociable times
Posts: 14,580
Received 435 Likes
on
229 Posts
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.
It didn’t work well and it never appeared as an aircraft modification.
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.
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.
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.
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.
Flarm Obstacle Warning System
Flarm began as a traffic warning system.
Popular in EU GA and gliders in NA, OZ and NZ.
Flarm began as a traffic warning system.
Popular in EU GA and gliders in NA, OZ and NZ.
Avoid imitations
Join Date: Nov 2000
Location: Wandering the FIR and cyberspace often at highly unsociable times
Posts: 14,580
Received 435 Likes
on
229 Posts
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.
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.
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.
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.
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.
Thread Starter
If you need the Wire Cutters.....that is a bit late on detecting the wires.
Originally Posted by [email protected]
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.
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
CG
Yes, I did rather a lot of that myself 
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.
Avoid imitations
Join Date: Nov 2000
Location: Wandering the FIR and cyberspace often at highly unsociable times
Posts: 14,580
Received 435 Likes
on
229 Posts
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
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
