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Foxbat down near Naracoote SA Nov 1, 2020


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4 hours ago, Jerry_Atrick said:

Glad to hear pilot will be (or should be) OK...

 

Noted that the ATSB were informed.. Do they investigate such actions for RAAus aircraft?

They don't in most cases, but sometimes do the whole investigation if it's something we can learn from.

Plenty of SWR lines in this district.

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On 02/11/2020 at 1:56 AM, Jerry_Atrick said:

Glad to hear pilot will be (or should be) OK...

 

Noted that the ATSB were informed.. Do they investigate such actions for RAAus aircraft?

No, tax paying Australian citizens are a low priority.

They are only interested in showboating to foreign countries.

$90 mill spent on MH370. More millions spent on ILLEGAL immigrant drownings.....

Seems like Australians mean nothing to Australia...... 

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On 01/11/2020 at 5:56 PM, Jerry_Atrick said:

Glad to hear pilot will be (or should be) OK...

 

Noted that the ATSB were informed.. Do they investigate such actions for RAAus aircraft?

I believe that they investigate if fatalities are involved Jerry.  ( Though I COULD be wrong here. . . .

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4 hours ago, Phil Perry said:

I believe that they investigate if fatalities are involved Jerry.  ( Though I COULD be wrong here. . . .

Not usually, the normal procedure for RAA accidents is they are investigated by local Police if injuries or fatalities occur, and Police call in RAA where they need expert advice. in preparing a Brief for the Coroner. The Coroner investigates the cause of death (not usually the cause of the accident.

 

The best was to describe ATSB's involvement with RAA is that they step in and take over if they decide it's necessary.

 

The reasons for this are best found by cruising through the Accidents and Incidents section on this site because most fatal RAA accidents are covered and you get to see the ATSB reasons.

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In searching for information on this crash, I found the locals seem to know all about it but none of them are saying anything so nothing to be gained there.

I also found an R44 spraying drainage channels at Bool Lagoon had also hit powerlines, and another crash of a Sportstar which had hit powerlines 21 km south of Naracoorte, making Naracoorte a kind of electrical Bermuda Triangle.

 

The Sportstar event shows how innocently you can become involved with power lines.

 

The pilot was flying from Naracoorte to Mount Gambier (a 30 minute flight), cruising at 600 feet agl.

Noticing a mob of cattle in his flightpath, he thoughtfully banked to avoid them.

His flight back jammed in the controls making the aircraft pitch down.

The aircraft struck a powerline and crashed into the ground.

As he was getting out he stepped on the powerline, burning his foot.

 

 

 

https://www.atsb.gov.au/publications/occurrence-briefs/2018/aviation/ab-2018-031/

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Are you saying it was a mechanical failure turbs, because that is how I read it. At 600' I would not think you need to avoid cattle, even emus can stand a two stroke at that height.

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7 minutes ago, Yenn said:

Are you saying it was a mechanical failure turbs, because that is how I read it. At 600' I would not think you need to avoid cattle, even emus can stand a two stroke at that height.

The Sportstar crash 21 km south of Naracoorte in 2018: No I'm not suggesting a mechanical failure, ATSB made a full report.

I also would have thought it wasn't necessary avoiding cattle at 600 feet.

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SplitS - "official story is not quite right" ... I nearly coughed a mouthfull of coffee all over the PC with that one

... that 'official story' issue is nearly always the case as the 'real story' gets fixed before anyone official gets informed in SO many cases.

 

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1 hour ago, Jabiru7252 said:

Avoiding cattle at 600 feet is a fair call. At that height the animals can get spooked, like horses do.

Not in my experience. I've done a lot of precautionary landings over cattle and sheep and they haven't moved.

I was going to say before that where this happened coincides with the Mosquito Plains, which is sheep country, so other than milk cows it would be very unusual to encounter cattle.

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Turboplanner is correct

Livestock especially these southern ones don't care about aircraft at 500' they generally do not even look up. Same with sheep.

50' and its a bit different.

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  • 3 weeks later...

I have some info on this crash.

He was landing and did not see the SWR line until it was to late.

Was ejected from the plane during the crash thru the windscreen very lucky to be alive.

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I wonder what static tension they run at. IE likelihood of breaking it versus it breaking the airplane.

 

low  droop catenarys have LOTS of tension. I would expect the cable to be good for a couple of tons.

Often  aluminium outer  with steel cable core.

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I really don't know. I doubt they are anything exotic. I've only ever been involved with them in Victoria. There's no doubt a spec. somewhere. Very basic insulator on each pole.. Poles about 25 ft (if that) from memory.  Nev

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SWER lines vary considerably in Calculated Breaking Load (CBL) according to the number of wire strands, and the thickness of the wire. 

 

Todays SWER lines are produced utilising specially-made, aluminium-clad, carbon steel wires. They can have 3, 7, or 19 wires, and the wire thickness can be 2.00mm, 2.75mm, or 3.25mm in thickness.

 

The CBL of a 3 strand wire of 2.00mm wire thickness is only 11.7kN - but a 19-strand wire of 3.25mm thickness has a CBL of 186kN. So you'd better make sure you pick a 3-strand wire to hit.

 

The 3 strand wire of 2.00mm thickness weighs just 74kg/km - but a 19-strand wire of 3.25mm thickness weighs 1,250kg/km.

 

A farmer mate in the W.A. wheatbelt was carrying out tillage on one of his paddocks, with an SWER powerline running almost parallel to his scarifier track. In W.A., many SWER powerlines are 2-wire, to supply 2-phase, 480V current for rural welders.

 

This was a 2-wire SWER line. As he swerved around one pole, he misjudged the scarifier-to-pole clearance, and "just nudged" the pole.

 

To his mortification, that pole promptly fell over - and as it went down, it took six other poles with it! The reason being, the holes for the poles are only loosely backfilled, the replaced soil is not compacted.

 

The wires did not break, but the line circuit breakers kicked out as the poles went down. So, a surprising amount of wire strength in that line.

 

If you hit an SWER, you're hitting a solid object that has to be moved from rest, before it either snaps, or tears through your aircraft frame. So that's a fair bit of inertia to overcome to start with, let alone the force required to break the wire.

 

The average span between poles on flat country is 400M. So the smallest single-wire cable you hit, contains nearly 30kgs of aluminium-clad steel - the largest cable you hit, will contain 500kg of aluminium-clad steel!

 

You could try fitting cable cutters to your undercarriage legs, but I'll wager few ultralights have enough inherent undercarriage strength to cut even a small SWER line.

 

The bottom line is - be very aware of lines of big poles, running across the countryside. You simply need to look for them, all the time.

 

The problem is, they don't necessarily follow any roads, fencelines or other visual cues - they just cut across country. The advantage is, they are always clear of vegetation, so they aren't hidden by it.

 

https://www.aflglobal.com/Products/Aluminum-Clad-Steel.aspx

Edited by onetrack
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