birdy

too many long posts for me, i get a sor head tryn to read that. but i did skim, and im not sure theres anythn i could contribute.

Birdy,
You should read this: http://www.rotaryforum.com/forum/sho...5&postcount=68
Regards, Mirek

thank you Birdy.

The other sound is partial disc stall, caused from a cyclic input of too high a rate for the blade to keep up.
The area of the disc being commanded to move the most in the cycle is where the partial stall will occure, and where the sound will come from.

Mine happened through a very high rate emergency cyclic input, on heavy rotors with low rpm, and from memory, it came from between about 7 and 5 oclock, the area of disc that was commanded to move the most in a hard left.
The only 'damage' i noticed, many months later, was 'bruised' cheek plates on one of the rotors.

I wouldnt say you didnt experiance a stall, but id think it was more likely a serious wake slap.
BUT, either way, its usualy more than one crack you hear. Wake slaps can last for several seconds with many cracks, and the stall i had had roughtly 4-5 cracking sounds.

Chuck Beaty described the sound best as that of a boat paddle be'n slapped hard on to water, sideways.

Gday Phil,
your testn me memory now, but its good coz its a sound iv only heard once, so i remember it pretty well.

Theres 2 different sounds a rotor will make. The normal wop wop, which is simply each blade slapn the disturbed slip streem of the previouse blade. The intensity of this sound can be anythn from barely audible to crisp and deep noted, depending on blade profile, amount of rotor over speed and the degree of 'unloadedness'.

The other sound is partial disc stall, caused from a cyclic input of too high a rate for the blade to keep up.
The area of the disc being commanded to move the most in the cycle is where the partial stall will occure, and where the sound will come from.

Hi Birdy,
I have a question about an incident you posted about. I found a thread where you experienced a loud crack from the rotor upon a hard turn. My question is the sound and location. I experienced a drastic pitch change in a gyro with a fiberglass cabin...spit me right out the left side, against the belt, and torque rolled right in a bad thermal. It sounded like the cabin split in half. I got my ass back in the seat and leg back in the cabin, throttle back, established a glide, and went straight to the ground. There were no odd flight characteristics and I didn't find any broken fiberglass or any issues for that matter. Got back in and flew away, no issues. The crack I heard was up behind my head, loud.
Can you tell me if you remember the noise you heard was directional and close or did it just seem to be there?

Thanks, Phil.

... and last one...
If you want to answer, I would appreciate if you could use my mail roman@gyroflyg.se

...message 3...
The video has been thoroughly analized by meny pilots and conclusion was that this was not a mechanical failure, this was pilot's fault. Too much speed forward with low disk AOA. I have difficulties to explain how he could fly during a few seconds before the stick was torn off from his hand. I still believe that the Sheik Mohammed or what was his name could do a better job. I think that I have rather good feeling about how near flapping he got 50% of my flying experience is on MTO Sport. But it is only what I think, I don't know, never crashed gyro myself :-(

Regards

Roman

... part 2...
I didn't get permission from person that crashed the gyro on the video I mentioned in my latest post, so I don't want to make it public. Still I do feel need to discuss it with someone more experienced. You can download the video from www.gyroflyg.se/20090801_low_rrpm_visingso.wmv
If you want to save it, it's ok for me but please don't spread it further. I'm going to delete it soon from my server.
... proceed to message 3...

Hello David,
I'm answering to you only because you asked questions and I don't want to get pissed by other's adrenaline if I reply to all. I'have got enough answers. I got in touch with an security specialist that teach on university in Lund, Sweden just what I'm interested of: Human factors with focus on flight security. What's more interesting is that he did his first gyro lesson two days ago :-)

Thank you for your answers to my questions on the forum. I'm not trying to argue your or elses opinions, there is something true in every post. I don't try to change anyone, it's beyound my capacities. I just want to, as long as possible, be able to say that no one of my students have ever crashed. Still I, as yourself, admire people that continuosly develop themselvs.

...see next message...