Thursday, Oct 17, 2013 at 13:03
You blokes were very lucky to have been given the "in-gorge" ride - but you probably weren't aware of just how much that chopper pilot was "pushing the envelope" by operating the chopper within
the gorge.
Choppers are the trickiest flying devices ever invented, and the smaller they are, the less margin there is between them being able to fly, and falling out of the sky with little warning.
There are dozens of critical parameters that a chopper pilot has to be on top of - and these include such things as main rotor RPM, tail rotor RPM, engine RPM, ground effect, the local weather conditions (temperature, humidity, wind gusts such as willy-willies can degrade chopper performance quickly), and operating weight.
Since the Robinson R44 crash at the Bungles in 2008, CASA have fallen on the chopper operators around the Bungles like a ton of bricks. The 2008 crash was a result of a heavily loaded chopper operating at its margins, encountering hotter conditions close to the ground - and a pilot who let his main rotor RPM decay, without realising it, and being unable to recover enough main rotor RPM in time to prevent a crash.
When a chopper flies outside its relatively narrow operating envelope in hot conditions with a full load, it's frightening to see how quickly they fall out of the sky like a stone.
Operating within a
gorge increases the chance of a rotor strike substantially (on un-noticed obstructions such as trees and projecting
rock formations) - as
well as encountering air conditions that can be drastically different to the plateau area outside
the gorge.
In addition, if tail rotor RPM decay is allowed to happen within the confines of a
gorge (leading to loss of rotational control), then there's little manouvering room within a
gorge to attempt recovery from tail rotor RPM decay.
The ATSB report on the 2008 Bungles crash makes fascinating reading, and makes you aware of how much a chopper pilot has to be "on the ball" and watching for the slightest deviations in engine RPM, main and tail rotor RPM, ground effect, local weather indications, and operating weight - as
well as un-noticed obstructions that will wipe out a chopper in milliseconds.
CASA have imposed a range of conditions on chopper tours at the Bungles to ensure that a repeat of the 2008 crash is unlikely to happen again - and one thing is for sure - flying down gorges below plateau level is most certainly no longer approved for paying members of the public.
http://www.atsb.gov.au/publications/investigation_reports/2008/aair/ao-2008-062.aspx (the PDF file contains the full report)
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Follow Up By: Coenen N & G (WA) - Thursday, Oct 17, 2013 at 22:57
Thursday, Oct 17, 2013 at 22:57
We were in the Bungles in May this year and did the chopper flight while there. It was just great. yes, maybe we didn't get the thrills you people enjoyed but even at the altitude we had to fly at, it was still a thrill and a trip we will never forget. We did a 30 minute flight at $325 each, so not cheap but it was money
well spent as there is no other way to experience the place as a whole.
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Follow Up By: Brett H - Friday, Oct 18, 2013 at 11:34
Friday, Oct 18, 2013 at 11:34
Hi Ron,
I totally understand the need for the change and deep down support it. I do feel lucky though to have experienced what I did. The funny thing was the guy who owned the video camera was too scared to go up so he fortunately gave the camera to me and another friend. 25 years later I still watch it and enjoy what we did.
And I've loved every other chopper ride I have done since without going through gorges. My other thrill memory is when flying high over
Katherine Gorge a couple of years after this trip and taking photos with my SLR (a film one). Same scenario, no door, lap belt and me leaning out taking a shot looking back towards the back rotor through the viewfinder. It was another moment of putting faith in a little piece of belt across my waist :-)
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Follow Up By: Ron N - Friday, Oct 18, 2013 at 12:35
Friday, Oct 18, 2013 at 12:35
G'day Brett - Yes, the smaller choppers sure give you the ultimate adrenaline rush, particularly when they're operating with doors removed, as most scenic flights do.
My wife and I did the chopper flight over the Bungles in July last year. I sat in the front and she sat in the back. I don't think she was aware before we took off, of the amount of wind buffeting you get in the back of the (doorless) cabin. She'd never taken a chopper ride before - I had my first ride in 1970, courtesy of the Green Machine. [;-)
At 120kts (222kmh), the wind buffetting is pretty solid in the rear seats, and you need to make sure every single item, including every item of clothing, is
well secured. In addition, it can get quite cold, so you definitely need a jacket!
The chopper flights today take a set scenic route with no deviations allowed (to assist with searches and to reduce flight risks), and no low level flying is allowed, the minimum standard height of 500' AGL whilst in flight must be adhered to. If you want to operate below 500' you need to undergo additional training and endorsement.
Here's a report on a smaller Robinson (R22) that crashed inside a
gorge on Louisa Downs in Oct 2012 with fatal results.
This flight was a "scenic tour" by a station pilot and he got caught out by a projecting
rock formation inside
the gorge, and possibly some disorientation in fading light. The tail rotor hit the
rock formation and the result was pretty predictable from there on in.
http://www.atsb.gov.au/media/4103767/ao-2012-133_final.pdf
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