Gyro fatal in Nowra

[alf jessup]

thank you Russ.thank you...awesome.. You fly Tecnam, right? dont want to appear ignorant...but Tecnam..thinking ..they had some dicey spam can a decade ago..always was scared of it of falling apart..just wasnt same as a decent built Ballina Lightwing 912..but times change... but flying a Technam...got nothing to do with a Gyro mate...we got some of them things next door... and the "new" Drifter 4 hangars up for 195,- @ Bill's seems a bargain :-)

Gyronimo,

 

Not quite making any sense out of you quote man, I am quite well aware flying a Tecnam has got nothing to do with flying a Gyro so where did that come from?.

 

Only comment I have made on the gyro recent accident other than say he could have put down in it if he wasn't comfortable flying in the conditions, other than that the other comment was that I have been in one myself and didn't like it.

 

As for being scared of my Tecnam falling apart, not as much as scared of a gyro shaking it's self apart.

 

Each to there own Gyronimo, that's what makes the world go around.

 

Yeah kind of finding it hard to understand what the hell you were writing about which referred to me.

 

Drifter 4 doors up? Bills seems a bargain? Thank you Russ, thank you, might pay in future to write whatever you wish to one person then gap a line or 2 and refer to the next.

 

I know I might only be a Victorian and this might be a Queensland thing but you lost me at the start.

 

Oh P.S the 1/4 to a 1/2 quote above was about member size hence the complaint to mum & dad.

 

Cheers

 

Alf

 

 

[Russ]

WTF ......has me bamboozled as well Alf.

 

Back on topic.....let,s now wait for the findings.

 

 

[104chocks]

Memorial service for the gyro pilot Mr Wilkinson - a good tribute and well covered by the local rag

 

http://www.southcoastregister.com.au/story/2180599/ken-wilkinson-farewelled-by-hundreds/?cs=12

 

 

[Bandit12]

The video may have already been viewed when I spoke to them, and they may have already discovered the reasons.

If that is true, they are running the risk of confirmation bias. You have to rule out the factors that didn't cause the accident just as much as rule in the ones that did.

 

 

[Bluey]

Spoke to the gyro instructor the other day who is pretty certain turbulence had nothing to do with the accident. Apparently the pilot flew from somewhere up on the escarpment to begin with. He also stated that the conditions on the day would have been fine for a gyro. I can confirm that I've seen gyros operating out of YWOL with westerlies gusting to more than 25kts on the ground.

 

 

[motzartmerv]

Apparently the pilot did not fly from up the escarpment. he has a small strip only a few miles from the accident site.

 

Several people that actually saw the aircraft, stated it seemed to be having difficulty with the winds.

 

 

[turboplanner]

Spoke to the gyro instructor the other day who is pretty certain turbulence had nothing to do with the accident. Apparently the pilot flew from somewhere up on the escarpment to begin with. He also stated that the conditions on the day would have been fine for a gyro. I can confirm that I've seen gyros operating out of YWOL with westerlies gusting to more than 25kts on the ground.

Motzart may have the more accurate version, but just looking at this for what it's worth:

 

Page 151 of the following link shows what I was taught was an adiabatic wind:

 

If the aircraft had come off the escarpment, in the beginning it would have had a very smooth flight travelling with a stable airflow. The danger in that phase would have been flying too low which was what the Stinson which crashed near O'Reillys was doing, trying to squeak through under the clouds. At that point the terrain starts to influence the wind hugging the downward slope, and it drove the Stinson down into the tress, overcoming its climb rate. As you get firther out from the mountain you get into more turbulence.

 

If you turn and fly along the downstream side this becomes much more of an issue, and the diagramme shows the rotors quite some distance from the hill profile, which I was referring to in a post above.

 

So forecast winds will tell you before the aircraft comes out of the hangar whether you can safety fly on the lee side of the hills or not - the degree of turbulence will directly relate to the wind speed.

 

The key point of whether the gyro instructor was correct or not is whether he had an accurate windspeed over the top of the ridges or not. He might well have been looking up at a clear sky, and the flying conditions in his location may have been perfect, but as we have just seen, the knots over the ridge will have the same precise effect as windspeed over a wing always lifting the airctaft off at the same speed on takeoff.

 

http://books.google.com.au/books?id=Mz_7qLK5hQcC&pg=PA151&lpg=PA151&dq=Meteorology + "Adiabatic wind"&source=bl&ots=6V9ittkN-b&sig=ZWf5Jo372_PK4ZAomplL5q8JXZg&hl=en&sa=X&ei=AKM4U5ZoqLOJB9SXgeAK&ved=0CC0Q6AEwAQ#v=onepage&q=Meteorology + "Adiabatic wind"&f=false

 

 

[Old Koreelah]

... flying too low which was what the Stinson which crashed near O'Reillys was doing, trying to squeak through under the clouds. At that point the terrain starts to influence the wind hugging the downward slope, and it drove the Stinson down into the tress, overcoming its climb rate...

Useful sources, Turbs, but I feel you are mistaken about the Stinson crash. The wreck is on the northern side of the range; they didn't make it over the top. See my Reply No. 7 below:

 

http://www.recreationalflying.com/threads/riddle-of-the-stinson.15439/#post-124034

 

 

[turboplanner]

That's interesting given you say you've been there. I read that the aircraft was simply forced down into the trees and the rescue was from the south side - pretty sure my information came from the riddle of the Stinson and what used to be up on the wall at O'Reillys (now a shadow of its former self with chinese souvenirs unrelated to the mountian), so I certainly stand to be corrected.

 

 

[motzartmerv]

True Tubz. Mostly.

 

This incident was no where near the escarpment, the entire flight took 10 minutes (as seen on the go pro video)

 

The crash site would be twice that distance from the escarpment.

 

One thing that seems to be lacking in most text ive seen on leeside rotor and mountain wave turbulence, is the key fact that the effects can be seen at many mutiples of the height of the hills, and at distances far further away from the foothills.

 

If you think logically. A strong rotor churns the air, in a vertical, downward rotor. That air, needs to be replaced by air above it. It doesnt just produce an area of vacuum, the air rushes in from above it to fill the space created by the rotor. That air, in turn is replaced by the air above it.. And son on. You can AND WILL get significant turbulence at heights far exceeding the height of the mountain range.

 

It is true however that by far the biggest danger area, is right up in the lee of the hills, below the hight of the peaks. This is where the roto=rs will be strongest, and the climb performance of the aeroplane may not be enough to get you out of the downdraft.

 

Not just our aeroplanes either, modern turboprops etc have issues as well.

 

 

[Old Koreelah]

The Stinson crash site is on Google Earth. They made it over a couple of spurs before coming to grief.

 

I assumed, Turbs, that you were saying they had been carried by a tailwind over the ridge, with insufficient power to escape the downdraft on the other side. On reflection, if the wind was from the south and had hugged the ground as it crested the range, they would have been battling a downdraught while trying to climb over that last ridge. You can never have too much power.

 

 

[Old Koreelah]

... You can AND WILL get significant turbulence at heights far exceeding the height of the mountain range...

True, Motz. Sailplanes routinely soar to 19,000 or more using the bounces downstream of Australia's worn-down mountain ranges. YQDI is miles from the Liverpool Range and yet we still get some turbulence from it.

 

 

[turboplanner]

The Stinson crash site is on Google Earth. They made it over a couple of spurs before coming to grief.I assumed, Turbs, that you were saying they had been carried by a tailwind over the ridge, with insufficient power to escape the downdraft on the other side. On reflection, if the wind was from the south and had hugged the ground as it crested the range, they would have been battling a downdraught while trying to climb over that last ridge. You can never have too much power.

Yes I was talking about them skimming the to with a tail wind.

 

I couldn't fin the book; found "Flight of the Phoenix" but not "The riddle"

 

 

[facthunter]

With the right conditions you will see this with lenticular clouds 50 miles or more from the originating geographical features, and may present as a series of waves. Local wind effects near steep rugged mountains can be severe. Very few of out craft climb much above 500 fpm, especially at height, and you can get sinkrates well above this, easily. The windshear and turbulence present control difficulties as well as being very unpleasant. Nev

 

 

[Guest ozzie]

classic accident was a Tri Islander in the Snowy's carrying chickens. Typical case of what you are trying to explain. Should be documented on the web somewhere. Was covered in the crash comics. Happened in the seventies I think.

 

 

[Jabiru Phil]

O'Reily statement to the coroner is well worth the read and should answer the question of location.

 

http://www.archives.qld.gov.au/Researchers/History/Interest/Pages/StinsonInquest.aspx

 

Phil