Posting Comment for "Helicopter Rescue at Queenscliff Headland"

*Author Name
Email Address
Website URL

About Posting a Comment

Comments are moderated before they will appear on the website, this is a manual process and may take some time. Please be patient.

Author Name is a required field.

Email Address is optional, but without one I won't be able to contact you back. It is never shown or linked on the website. You can always just email me if you'd rather not post a public comment. I generally reply in-line with a comment rather than email you back, unless I want to discuss something in private or off topic. Please check back to see when I reply.

Website URL is optional, if supplied the Author Name will be hyperlinked to this URL.

You may use wikitext in the body, preview may be handy here. Don't worry if you can't figure them out, just give me a hint what you want linked to what and I'll do it during moderation. Wikitext is not BBcode!

Spammers: Please don't bother wasting your time scripting up posts to this form. Everything is moderated, your post will never be seen on the web even transiently, there is no way to even view it by its internal ID, it will never be indexed. I will simply delete your post in the moderation interface. If I'm your target audience you're really on the wrong track; I'll never click on a URL in your garbage. The post content is not emailed to me (and I don't use a Win32 mail client anyway), I view the posts in plain text in the moderation interface so no clever tricks of any kind will make anything you type be interpreted by anything other than me, a human. Just give up and go elsewhere please!

1st June 2010 09:43

Critical Alpha wrote...

G'day Alan,

nice video. It's interesting that you put the noise down to turbine noise. There's been a fair amount of research on this and I think it's reliable to say that the majority of the noise doesn't come from the turbine, instead coming from the rotors and the gearbox. The latter source is a major source of noise - and of crew hearing loss, a subject near to my own ageing ears! during those evolutions the main rotor would have been at high collective pitch/high angle of attack therefore adding to its contribution to the noise.

Here's a quote from the UK CAA, which doesn't however point to the gearbox:

"The noise “signature” of helicopters differs significantly from that of fixed wing aircraft. The noise comes more from the main and tail rotors - particularly from their tips - and proportionately less from the engines."

It would be interesting to calculate the angular velocity of the blade tips, using your estimate of 250RPM for the rotors. Tip speed is a major limitation of helicopter performance. The advancing blade tip speed is a combination of it's angular velocity and the speed of advance of the helicopter...

Nice post, thanks.


26th May 2010 22:44

Alan Yates wrote...


No sorry mate, I only took video.

Checking the raw video quality, it isn't that great... The resolution is only 640x480. No frames where you can recognise anyone. Here are a few of the better ones.

Video Frame 1
Video Frame 2
Video Frame 3

Did all turn out well for the patient?



26th May 2010 20:02

Steve Flanagan wrote...

Hi Mate,

I was the winch operator on the helicopter, would you happen to have any still photo's of the job?



24th May 2010 13:34

Alan Yates wrote...

LOL Alan, you know me too well... I didn't use the video footage, rather the audio. I was looking at the spectrogram in baudline last night. Can't remember the figure, about 250 RPM IIRC. I'll post a spectrogram later.

24th May 2010 13:14

Alan wrote...

Cool. I'm surprised you haven't done a calculation of the heli's rotor speed given the frequency of the cameras frame rate. :)