Flight hours and cycles are two almost totally Independant contributors to structural damage. The Hawaii 737 is the poster child for the importance of cycles. If cycles were an issue for tour hellos, something would have popped up by now. There is another issue involved in this accident.

Utility
 

6 to 8 hours a day..

Yes….welcome to the world of utility flying and actually “working” a helicopter. It is certainly not for the faint at heart.

Shameless plug: I do have 2 positions open for “apprentice utility pilots” if anyone is US legal with 2,000 hours and wants to get into this type of work….fire & power-lines primarily…power work is all HEC in Bell 407’s or BK 117’s.

Juan Browne has recently also uploaded the video but now with the audio apparently synchronised with the video (presumably by matching the fuselage striking the water with the sound of such an impact):


The caption at the start suggests the frequency of the sound heard during the lead-up to the breakup matches the rotor RPM. Is that really the case? In any case, it certainly reduces in frequency over time suggesting what ever it is is slowing down. I am not sure if video or audio are at 'live' speed. Not even sure the audio is from same location as where this video was taken? To me the sound seems more like a jack hammer being used in the bowels of a ship. The regular sound of a 206L can't be heard beforehand either, why? Was sound of the breakup so loud that it dominated anything else picked up by the microphone in a busy city?
Once the source of audio is validated, should be straightforward for NTSB to analyse its dominant frequency and whether that matches main rotor RPM, tail rotor RPM or tail rotor drive shaft RPM (if different) or anything else, including harmonics.

With the sound synchronisation, the "banging" is already starting before the helicopter emerges from behind the building.

That is why most helicopters track "RIN's", which for those that do not know is "Retirement Index Number". So for example on the L4, lets say I flew 6 hours, 4 landings and lifted 37 buckets of water, the RIN count for the day would be 2(lifts + landings), therefore 2(37 +4) = 82. This number is then used as a multiplication factor on various life limited components.

I saw the original video, with the speed of sound delay. There's a sort of dog bark sound very early on, it might be nothing, it doesn't sound mechanical. I'm not sure why the microphone so clearly picks out the diabolical thwopping noise, but the processing on some security cameras does normalise sound, especially distant loud noises, and it can make them sound much closer.

Hi guys. Just clicked into this site.
we have operated 206 Tours in the past. The machines were rigged for duel pilot operation for recurrent training, et cetera
but when operating with passengers, the copilot pedals were enabled ,has anyone asked the question about the copilot pedals position at the time of the catastrophic failure?

It would be expected that dual controls would be removed for operations of this kind. Had pedals remained fitted, their position would match the position of the pilot pedals. In any case, it appears that the front seat passenger was a child who would not have been able to cause any issue with pedals.

Yes.
It helps to scroll back and read the discussion before offering repeats.

in any case, I have had a copilot apply full pedal at 100 kts (well, maybe 97! ), in a B212, and my tail didn’t come off. He decided to adjust his seat fore and aft, after I gave him control so I could eat my bacon roll. The floor was wet, and didn’t offer any friction, so his foot slipped with full force. Never did get to finish the roll as it ended up in the chin bubble……

I hate it when my in-flight meal is cut short. :-(

212Man,

Wasn't there a similar kind of incident experienced by that Operator that wound up with the 212 in the water?

I had one bite, and might have spat that out too!

I don’t think so. Our 212s in the water were CFIT at night (North Sea), disorientation and loss of airspeed (North Sea), blade delaminating (Nigeria), swashplate failure (Nigeria) and another Nigerian ditching that was never established. Maybe others I’m not aware of

I know you guys dont like it when people theorize about these crashes before an official report, but look, its what we do so may I?
Everything ive seen, and in particular the NTSB footage of the guy poking around the tail, suggests the tail rotor drive shaft bonds failed and cut the top of the tail boom open leading to loss of anti torque control, and an immediate yaw leading to loss of lift and low G resulting in the rotor being unloaded and the head hitting the mast and bending the mast at the transmission, ripping the entire lot out of the roof as a seperate event after the severing of the tail boom,
The pics of the inside of the tail boom show about 3-4 scratches where, after peeling that 20cm section open, the vibrating spinning driveshaft started whacking the split open piece of steel on its white side and only had a fraction of a second to work 3-4 lines of the white paint off.
Someone posted the video of the sound enhanced thing a few posts back, I think thats the sound of the TR driveshaft smacking around in its little cover.

It was going fine until you said this:

But, I’m not opposed to the idea that the transmission detaching could have been caused by a combination of dynamic, and aerodynamic forces, resulting from the loss of the tail boom just aft of the mounting point. Why it detached, I have no idea, but I very much doubt it had anything to do with a flailing TR drive shaft. Because of the speed they run at, they experience low torque and so are very lightweight. My earlier remarks were connected to the suggestion of the pax applying pedal.

No no, im saying, the TRDS failed and caused the body to yaw. The yaw caused the blades to be rotating at a slower rate, which means, less lift. This a bit like dropping the collective, when it comes to disc loading.
So im not saying the TRDS vibration jolted the main transmission mounts off, im saying the helicopter ended up in a disaster because of the failure of the entire tail rotor and boom, and then that led to the loss of loading on the disc.

When the tail rotor fails, the helicopter spins. That sudden uncontrolled spin throws off the balance of the main rotor, which then can’t keep lifting properly, so it becomes ‘unloaded’ and stops holding the aircraft up. Mast bumping did then occur, but it happened after the main event. It itself was not the main event.
In other words, the tail rotor stops working, and the whole helicopter starts spinning. Because there's nothing for the engine to push against anymore, the main rotor slows down in relaion to the air. And when it slows down, it cant make lift anymore and the helicopter falls.
That falling, is so quick and is effectively immediate, and would have resulted in the pilot pulling back on the cyclic, almost certainly sealing the fate of the rotor mast assembly.

EDIT: i should add, im quite focused on the images that helispotter also refferenced earlier on, where he showed the angle of the mast coming out on an angle from the transmission. Theres no goood foootage or photos yet close up, but it looks like a pretty good indicator of engine induced damage, not from hitting the water. Mast bumping usually bends or snaps the mast but theres no rules about what that must look like. typically with robbies its a completel crack and separation. The 206 mast is prety hefty.

Jeremy, I have no idea what your background is, but I suggest you re-read your post carefully and do some research. Then delete it!

I try to keep out of discussions as a Mod but I wholeheartedly agree with 212man here!

JeremyThompson you have a severe lack of knowledge about mast bumping which affects the head of the mast, not the base. Your post history indicates a fascination with accidents along with an overall lack of understanding of the backgrounds.

Any more of such contributions to this thread will result in an Access Mask being applied to you for this Forum.

The speaker of the house has speaked.