Calidus crash video?

ckurz7000

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Looks like your regular blade flapping accident on takeoff.

-- Chris
 

Mike G

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It's genuine, it happened in France, the pilot/owner is recovering and posted that video on the French forum.
Mike G
 

JAL

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What is inducing the roll?

Is it asymmetrical lift created by the rotor not being able to teeter as far as it needs to or is it that when blades flap they stall and as result the gyro enters a propeller induced torque roll?
 

Vance

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Not correct in my opinion.

Not correct in my opinion.

So blade flapping, just reduce power to correct?
In my opinion gyroplane blade flap is caused by stalling a rotor blade.

I feel if the rotor is turning too slowly and the cyclic is brought back at too high an indicated air speed a rotor blade may stall leading to a divergent blade path.

In my experience the best response at the onset of flapping is to flatten the disk as soon as I feel the stick shake from the flapping.

I don’t know why this gyroplane pilot didn’t know that an airfoil will stall at too high an angle of attack.

I feel this is something that should be taught before the first flight lesson in any aircraft, not just gyroplanes.

Regards, Vance
 

JAL

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In this video it seems that he was in the air when the flap occurred? The only instances of blade flap that I am aware of occur while the gyro is on the ground.

What I don't understand how does one get the blades to flap if you are flying. I have only been aware of blade flap occurring on the ground, mostly in the transition from pre-rotation to take-off when the pilot accelerates to fast and doesn't allow the rotor rpm to match the airspeed, but once the rrpm is over a critical amount then blade flap can't occur.

So if the gyro has lifted off doesn't that mean that the rotors are spinning fast enough that blade flap cannot occur? Would you not have to do unload the rotor somehow first reduce the rrpm below the critical rrpm first then load it back up abruptly to induce flap while flying? Like a rapid forward stick movement to induce low Gs on top of a zoom climb then rapid pull back on the stick after the rotors slowed down below the critical rrpm.

As far as critical angle of attack is concerned I would think one of the challenges with a rotor that the angle attack of the rotor does not necessary give any visual cues to the pilot. In other words unlike a fixed wing the pitch of the fuselage is not necessarily a direct correlation thats reflects the angle of attack of the wing, its variable. In a fixed wing the fuselage will always pitch up exactly the same amount each time according to the angle of attack of the wing and therefore the pilot gets both a visual cue and instrument cue (airspeed indicator) about how much angle of attack is being applied by the position of the stick, what is seen out of the windscreen, and what the ASI is showing, in a gyro the pilot only has the position of the stick to determine how much angle of attack they are applying.

So rather than focus on angle of attack (after all gyro cant stall) the pilot should focus on rotor rrpm in relation to the stick position.
 
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Vance

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In this video it seems that he was in the air when the flap occurred? The only instances of blade flap that I am aware of occur while the gyro is on the ground.

What I don't understand how does one get the blades to flap if you are flying. I have only been aware of blade flap occurring on the ground, mostly in the transition from pre-rotation to take-off when the pilot accelerates to fast and doesn't allow the rotor rpm to match the airspeed, but once the rrpm is over a critical amount then blade flap can't occur.

So if the gyro has lifted off doesn't that mean that the rotors are spinning fast enough that blade flap cannot occur? Would you not have to do unload the rotor somehow first reduce the rrpm below the critical rrpm first then load it back up abruptly to induce flap while flying? Like a rapid forward stick movement to induce low Gs on top of a zoom climb then rapid pull back on the stick after the rotors slowed down below the critical rrpm.

As far as critical angle of attack is concerned I would think one of the challenges with a rotor that the angle attack of the rotor does not necessary give any visual cues to the pilot. In other words unlike a fixed wing the pitch of the fuselage is not necessarily a direct correlation thats reflects the angle of attack of the wing, its variable. In a fixed wing the fuselage will always pitch up exactly the same amount each time according to the angle of attack of the wing and therefore the pilot gets both a visual cue and instrument cue (airspeed indicator) about how much angle of attack is being applied by the position of the stick, what is seen out of the windscreen, and what the ASI is showing, in a gyro the pilot only has the position of the stick to determine how much angle of attack they are applying.

So rather than focus on angle of attack (after all gyro cant stall) the pilot should focus on rotor rrpm in relation to the stick position.
In my opinion an airfoil produces lift until it stalls beyond some critical angle of attack.

I suspect too high an angle of attack from a lift off with too much airspeed and not enough rotor rpm.

It is hard to tell from the video.

Given enough indicated air speed I suspect a gyroplane could lift off at very low rotor rpm. I don’t know because I haven’t tried it.

I have felt the onset of blade flap and corrected it with forward cyclic to reduce the angle of attack of the rotor blades.

I feel it is important to understand what makes an airfoil stall.

Regards, Vance
 
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JAL

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.

Looks like the first video was this RC crash from a different angle

https://www.youtube.com/watch?v=Jx13srJx8bU

Make note of the similar green color on the rotor blades

The real Calidus owners should tell the modelers to stop using their name
I agree that the first video looks odd but the rotors hit dirt, in the one you posted the rotors hit the tarmac so I don think they are same.

The first video does look strange in that the gyro looks to be to small for a full size gyro but looks to big for a model.
 

Steve_UK

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If you look at my Gyro Accident Blog listing you will find it listed for

24th October 2014 - French Registration 83-AMW

This very same machine had just finished being repaired from a previous accident.

see news photo here

http://www.ledauphine.com/ain/2014/10/24/un-avion-se-crashe-au-decollage

There is a suggestion ( maybe incorrect ) that the canopy may have opened during the take off run - if so imagine the distraction and the change of weight balance/air flow at that critical moment.


Steve
 

Arnie Madsen

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I dont doubt there was an accident in France

But I am not sure that the first 4 second video was it .... I could be wrong .... hard to see but there is a flash of reflector green on the rotorblades in the 4 second video .... that looks much the same as in the one I posted of the RC Calidus crash.


Here is yet another Remote Control "Calidus Crash" ... I say again those RC guys should be told to stop ruining a copyrighted brand name.
https://www.youtube.com/watch?v=bkFV6O_yC3o
 

Resasi

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With regard to blade flap in the air. My Instructor in the UK. Tony Melody who has around 3,000hrs of instructing in gyros stated that he had experienced blade flap in the air with DW rotors. It did not progress, but the rotor would not accelerate, I believe he landed from this incident.

I and others during training at Little Rissington a few years ago witnessed one of our experienced members taking off in his Cricket to depart the field. He lifted off then levelled off and flew parallel to the runway. We thought he was building speed before climbing away.

At the end of the runway he passed over the hedge and disappeared from sight into the valley beyond. On his return he reported that all had seemed to go normally until he had lifted off. While still in ground effect the rotor did not accelerate. At some point he having committed himself to the take off just made it over the hedge and only with falling ground was he then able to put the stick forward and seemingly ‘unstick’ the blades which then seemed to accelerate normally. This again was with DW’s.
 

Steve_UK

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I'm not a pilot but have been lucky enough to fly in Mi-24 Hind, Mi-2, Mi-17, Lynx HAS3, Gliders, GA
"But I am not sure that the first 4 second video was it .... I could be wrong ...."


Yes I think you are.
 

Fly Army

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If it is legitimate it appears to be the case of becoming airborne too early. The roll occurs as soon as he try's to leave ground effect.
 

Jazzenjohn

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It looks like an overrotation with the blades at minimum flying speed, but it is difficult to tell. The model crash appears to me to climb higher before rolling left, while in the French accident the gyro appears to roll right almost immediately after it leaves the ground. They don't seem like the same accident to me.
 
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