PPRuNe Forums - Fatal Crash Broome 4th July 2020

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Excellent post Winfield83, thank you!

Excellent observation, but remind me, wasn't this an almost brand new helicopter with a couple of hundred hours total time? In which case most unlikely anything on it was worn out.

This was a fairly new machine with less than 300 hours
I am sure the factory would have assembled it properly

If it turns out some component in the TR drive was not assembled properly
or tightened properly it most likely happened during disassembly & reassembly
when it was shipped overseas.
That is my guess anyway.

The tubes and sometimes bush asembly can wear quite a bit and should be inspected closely during routine maintenance, particularly when operating in dusty environments. Add in to that some young hopper (or old...... some just never grow out of it) going from one control stop to the next in their own dust and using a multitude more inputs than necassary, than an already prone bearing surface will have an even rougher ride.
I would think though, that excessive wear to the point a failure of a tube or guide would occur, would more likely lead to jammed pedals rather than a complete control failure/disconnect. Very unlikely also in such a low houred aircraft.
Also, a complete control disconnect should have no affect on the teetering of the tail rotor and should not lead to a blade striking the tail. Definitely lead to a few other problems but I wouldn't think that would be one of them.
Anyway, I'm teetering on the edge of speculation and that's something I try not to do before the ATSB has done their thing. A sad tragedy whatever the cause.

ATSB Final Report

Have a look at the standard of aircraft operation in the Wild North West of Western Australia.

Contributing factors

Following a period of pedal vibration over at least 2 flights, overstress fracture of the attachment lugs of the tail rotor gearbox input cartridge occurred. The source of the loading that led to the overstress fracture was not conclusively determined.
Two pilots experienced vibration through the helicopter’s tail rotor pedals on separate flights and did not endorse the problem on VH-NBY’s maintenance release. Additionally, following tail rotor inspection and vibration analysis on the ground, the engineers did not endorse the requirement for a maintenance check flight on the maintenance release. As a result, the value of the maintenance release as a tool for communication and management of airworthiness was lost.
A recommendation in the R44 pilot's operating handbook was not followed. It advised pilots that following detection and inspection of an unusual vibration, they should hover the helicopter then have it reinspected before resuming free flight.
The pilot conducted a towering high-power take-off in VH-NBY from a confined area with 3 passengers on board. The unnecessary carriage of passengers resulted in a significantly more severe outcome following the inflight breakup.
Shortly after take-off, following the overstress fracture of the attachment lugs, the tail rotor gearbox separated from the helicopter. This led to fracture of the aft tail cone bulkhead and separation of all components attached to it, including the horizontal and vertical stabilisers.
With limited time and the stress associated with the emergency event, the pilot did not apply the pilot’s operating handbook procedure for responding to a tail rotor emergency. Prompt application of the procedure would have reduced the likelihood of loss of control, and therefore improved the potential for survivability.

Other factors that increased risk

The pilot did not have a valid flight review for the R44 helicopter type or a current medical certificate. The former increased the risk of an inappropriate response to the tail rotor emergency and the pilot was not legally authorised to operate an R44 helicopter at the time of the accident.
The owner of VH-NBY demonstrated acts of non-compliance with multiple aviation safety regulations. Additionally, VH-NBY was operated in a manner that increased the risk of damage or stress to the helicopter on multiple occasions. These actions had an adverse influence on safety and imposed unnecessary risk on passengers and third parties.
Although the registered operator of VH-NBY was responsible for the continued airworthiness of its helicopter fleet, they did not employ a conservative defect resolution process that would have supported further trouble shooting.

Other findings

The attending engineers found that visual inspection of the tail rotor system and associated components, running the helicopter on the ground, and dynamic tail rotor balancing, could not replicate the stated problem. It is likely that the vibration only presented in powered flight.
There was a history of unreported accidents and incidents with the registered operator of VH‑NBY's aircraft, in both commercial and private operations. These occurrences included 2 tail rotor strikes in different R44 helicopters, and a total hull loss of another R44 helicopter (VH‑ZGY) that resulted in serious injuries to a passenger.
Although a fuel bladder was punctured during the accident sequence, and fuel was lost from the tanks, the fuel bladders reduced the flow rate of escaping fuel, which reduced the risk of a post-crash fire.

So just a freak accident, that no-one could have anticipated! :ugh:

Obviously surveillance must be improved, with more of these types of operators removed from the airspace ASAP.

Before innocent casualties become involved as they were in this case. Very sad.

The trust betrayal of the passengers and the young girls parents is disturbing, and potentially speaks volumes regarding the pilots personality.

I got to thinking...

1) Low-time machine and the tail rotor comes off? ATSB cannot find a definitive cause?

2) You know how we always caution pilots to operate the helicopter within limits so something doesn't break on the next pilot? Maybe this guy was a victim of...well..himself. Maybe he was his own "next pilot." The ATSB cast aspersions on him, noting all the other incidents and accidents his helicopters have been involved in. Add to that the fact that he was technically not legal to fly, which demonstrates a certain casualness with rule-following. We might infer that this casualness carried over into how he operated the ship. Perhaps he was not diligent about observing power limits while at the same time being more rough on the pedals than is necessary? We don't know what he did with that R-44 in the 280 hours he flew it, but I'll bet it was used and abused. Maybe this guy did it to himself? Maybe he was used to horsing those things around? His history certainly hints at this.

3) Here's one amazing tidbit from the investigation:

Quote:

While there was a large shift forward in centre of gravity it is highly likely that VH‑NBY’s centre of gravity remained within limits following the in-flight break-up.

Are you kidding me?? This implies rather strongly that the ship could have remained controllable and *perhaps* landed safely after the "event" (as has evidently happened before). How many other helicopters can do that? The ATSB does go on to say that once the rotation began, proper control inputs (e.g. closing the throttle and getting rid of the torque) would've had to have been done within one rotation as the lateral g-forces become too high to manipulate the controls. As someone who had an actual t/r d/s failure in a 206 in a hover which went 'round a couple of times, I can attest that the lateral forces quickly become high and disorienting. And remember, the 206 has the mast above the back seat, not behind the cab like the R-44. So the 206 pilot is closer to the center of rotation, in other words.

I've never been an outright Robbie-hater, and my respect for the R-44 has grown with this accident.

I've been an R22 hater but have no gripe with the R44 apart from that rotor design.

Have a look at the standard of aircraft operation in the Wild North West of Western Australia. Contributing factors

Other factors that increased risk

Other findings

Have a look at the standard of aircraft operation in the Wild North West of Western Australia.

Contributing factors