Is this the new speed world record????

[Jamin_00]

Holy sheeeeeeet, looks awesome but ends BADLY

Optipower pilot Stefan Segerer.


I dont think there is a harder way to crash than this

[danch]

Ouch !

[madgooner99]

wooow. Hard crash...not nice to see

[pug907]

It's amazingly complete for the speed it went in at. I thought it was going to be shredded. Mine look worse than that, going in at 10th of the speed

[miskin]

BOOOOOOM

They should have used a MCPX BL ... They could have popped the links back on and gone again
Joking aside it looked impressive . Any idea what caused the impact ?

Anthony

[KevDavies]

JEESUS!! Go big or go home or what!!! Thats a rekit minimum!!

[BobJ]

Hi


Almost certainly just divergent (pitchy) above a certain speed, all heli's model and full size will get divergent due to the difference in airspeed on the advancing and retreating blades.

Cheers
Bob

BOOOOOOM

They should have used a MCPX BL ... They could have popped the links back on and gone again
Joking aside it looked impressive . Any idea what caused the impact ?

Anthony

[Rotorhead]

BOOOOOOM

They should have used a MCPX BL ... They could have popped the links back on and gone again
Joking aside it looked impressive . Any idea what caused the impact ?

Anthony

Probably a link giving up.

[Boggy]

We saw this happen a couple of times with Stu Smiths logo 600 during speed runs ! luckily his decided to go upwards both times. Its very disconcerting the heli flys straight and level then suddenly without any warning changes direction by 90 degree's!

[Jamin_00]

We saw this happen a couple of times with Stu Smiths logo 600 during speed runs ! luckily his decided to go upwards both times. Its very disconcerting the heli flys straight and level then suddenly without any warning changes direction by 90 degree's!

Going up is likely too light blades or too high rotor gain.

Going down like this is something else. Servo giving up or fbl unit getting confuzzled. Did look like it was a little up and down slightly which would be blades or gain but he runs heavy blades so likely the fbl unit??

I'm sure we will hear soon if its a servo or link IF they can tell as it went in HARD!

[hanson]

given the force that went in with, i didnt think it looked to badly shaped, just hope the kosmik was alright, poor thing. the pilot looks ****sssed.

[Jamin_00]

Apparently all the guys are running around 2600rpm!!!

That must be right on the limit of the blade tips going super sonic so this would be the limit of headspeed?

[pgkevet]

Assuming a 2metre disc diameter and speed sound at sea level of 340m/sec the rotor speed 3238/min for supersonic tips if heli is stationary.
If travelling at 250kph i.e 70m/sec then only got 270m/sec rotor tip speed to play with = 2592/min

So yeah, right on the limit and might be the reason.

Needs a new blade design to cope with the transition?

[tomatwalden]

We saw this happen a couple of times with Stu Smiths logo 600 during speed runs ! luckily his decided to go upwards both times. Its very disconcerting the heli flys straight and level then suddenly without any warning changes direction by 90 degree's!

I guess without doing the maths on blade (rotational) airspeed versus helicopter airspeed, you can't know for certain, but a retreating blade stall WILL always pitch the nose up due to phase lag (blade pitch takes effect 90 degrees later in the disk). The nose-down nature of this doesn't fit this scenario though, so mechanical failure would be my guess ...

[pgkevet]

I guess without doing the maths on blade (rotational) airspeed versus helicopter airspeed, you can't know for certain, but a retreating blade stall WILL always pitch the nose up due to phase lag (blade pitch takes effect 90 degrees later in the disk). The nose-down nature of this doesn't fit this scenario though, so mechanical failure would be my guess ...

If going supersonic on the rereating blade tip is that a stall? I understood that the centre of pressure moves as transitions to supersonic whihc would twist the blade ( but not sure which way)