Ground Resonance

[Sospan]

I don't think this has been done before, they show it on ATM multi-skilling and probably on the chinny Q course.

But for all that haven't seen it, this it what happens if some serious ground resonance kicks in ! oh and you just happened to be chained to the deck !DT_Xtremez_17:

http://uk.youtube.com/watch?v=a4EvVR10AF0 youtube.com/watch?v=D2tHA7KmRME&feature=related

 

[Scaley brat]

It has, a couple of times mate ! DT_Xtremez_31: C+ can do better !! DT_Xtremez_31:

 

[Sospan]

It has, a couple of times mate ! DT_Xtremez_31: C+ can do better !! DT_Xtremez_31:

ohhhhhhhh arse ! I done a damm good search too, trust me to repost something. Oh well I will leave it here in case some folk haven't seen it. ::/:

 

[metimmee]

spfelling

spfelling

The resonance looks bad enough but appears to cause structural failure when the rotor-brake is engaged....I assume thats what the puff of smoke is just prior to the aft pylon failing.

 

[Mohammed The Bear]

Now I'm no techie and know fukc all about nuts and bolts but by my reckoning that Wokka's fukcedDT_Xtremez_42: Can anyone enlighten me as to how and why this happens?

 

[Sospan]

Now I'm no techie and know fukc all about nuts and bolts but by my reckoning that Wokka's fukcedDT_Xtremez_42: Can anyone enlighten me as to how and why this happens?

Have a read here!

Or here
DT_Xtremez_27:

 

[Mohammed The Bear]

Have a read here!

Or here
DT_Xtremez_27:

FOOK

Ta for that Sospan, every day is a learning opportunity DT_Xtremez_30:

 

[Harry B'Stard]

Ground resonance

Ground resonance

Quality clip sospan,

never witnessed it before, but from my time on the mighty flying death Banana I remember the aircrew were very paranoid about oleo extensions and tyre pressures.

They even refused to land with a punctured tyre, prefering to land on a strategically positioned sandbag wall to support the rear frame!

As regards to the amount of damage, I remember an incident where similar damage to the rear pylon was caused when the pilot flared too much on landing.

Last I heard it had been repaired and was once again battering its way through the air!

HTB

 

[enginesuck]

is it me or does that chinny look like a scale model??

 

[sumps]

ER... then there is water resonance...

 

[metimmee]

ER... then there is water resonance...

That thing just wont die!

 

[Hammer and stillson]

The resonance looks bad enough but appears to cause structural failure when the rotor-brake is engaged....I assume thats what the puff of smoke is just prior to the aft pylon failing.

Only if its a RAF one, none of the other fleets have a rotor-brake fittedDT_Xtremez_42:

 

[Rigga]

Errm... I seem to remember quite a few US Army 47D's with Rotor Brakes!

In fact I can't remember seeing any without Rotor Brakes!!

And I don't think its the rotor brake being applied - I think its the Combining transmission being Ripped Off/Failing just before the rotors eat each other.

I remember a Chinny being tested to ground resonance at Boscombe in the late 80's and "we" got a full set of wheels back with sideways scrapes taking about two-three inches neatly off the Wheel halves (no tyres came back)

An old Chinny Ferry tank (Ex Andover Ferry Tanks were used at that time) had the internal baffles removed to make the resonance happen.

 

[Hammer and stillson]

Only going from what we were told on our Q course and the dutch guys on the course with us confirmed their cabs don't have it either.

 

[Past Engineering]

On one of the 18 Sqd Chinooks that I was carrying out the first rotortune post blade change, the pilot started her up, as the speed buit up we started bouncing about a bit, as it approached ground speed the cab really started rocking and bouncing, which was scary in as much as we had aircraft either side of us on the pan. I started the box to take the readings when the pilot said 'you have about 5 secs more and I am shutting down' I told him I had a set of figures I could work with and I have never seen a shut down so quick, it included a smoking rotor brake as well. Walking back with the pilot he said if I could not convince him that we had made enough adjustments to stop it happening again he was not going to do it.