ASRA new safety directive for TAG gyroplane.

[Steve_UK]

Who will cover the costs if some need new blades or other parts?

 

[Kolibri]

Yes, I believe the loss of the blade weights may be the cause of the crash at Forest Beach.

Vance, I agree that blade weight loss "may be the cause of the crash at Forest Beach" . . . but that was not my question.
Do you agree with Chris that it "appears to be" the cause? You earlier implied that it did with your "Glad they figured it out Chris."

The text of the SD reviews the new information & observations that provide more information on the likely cause of the tragic accident in Western Australia!

My point is that ASRA's "real possibility" is not equal to "likely" cause.
This has not yet been "figured out" and it is inaccurate to claim so.

___________

I believe Chris has already commented on the grounding and the latest ARSA directive

Jeff, yes, she wrote the below:

All our USA TAG owner's have received this information prior to the publication of the ASRA Safety Directive and are aware!

However, since ASRA has no jurisdiction here, I was wondering aloud if USA owners considered themselves grounded (i.e., on a prudent though voluntary basis).

Regards,
Kolibri

 

[Uncle Willie]

...When did "Possibility]" become a synonym of "Probability"? ...

They have been Synonyms for a very long time.
https://www.thesaurus.com/browse/possible

... My point is that ASRA's "Real Possibility" is not equal to "Likely" cause...
... Do you agree with Chris that it "appears to be" the cause? ...

Apparant = Possible =Probable = Likely

https://www.thesaurus.com/browse/apparent?s=t

Appears to be = Real Possibility = Probable Cause = Very Likely

English is a difficult language due to the variable meaning of words.
Add to the challenge that the ASRA investigators are speaking Australian English and Not British or American English.
Words in Australian English have different nuances from the same words in American English.

Quit Nit-Picking over the words.
It serves no purpose and just tends to annoy everyone.

https://www.thesaurus.com/browse/nit-pick?s=t

 

[j bird]

Actually my sentiments, Bill,!!!!!!!

 

[JEFF TIPTON]

True due diligence will probably be applicable in this case. From what I have read TAG has identified the serial number range of the effective rotors and they may expand that range as all parties continue to evaluate the data.

That the ARSA is allowing on case by case basis to flight status is encouraging.?

The machines here technically are not effected by ARSA, but I believe the owners here are working with the dealerships to clear up any confusion regarding there machines and there status.

If if I remember correctly Chris indicated the machines here are outside the serial number ranges effected. I would not be surprised to find that TAG will develope a procedure to positively identify the effective blades.

 

[Kolibri]

Flip a coin: while landing tails is possible, it is not probable.

If the words were true synonyms, they could be reversed without destroying the meaning.
But that's not the case here:

Flip a coin: while landing tails is probable, it is not possible.


Uncle Willie's "They have been Synonyms for a very long time." is not the case in ASRA's usage.








If ASRA meant "probable" or "likely" they'd have written it that way, even in Australia.
In fact, they pointedly used "possibility" in the sense of feasibility, not likelihood:

There is a real possibility, therefore, that if such a massive instantaneous rotor imbalance occurred with the Forrest Beach Titanium Explorer, then the failure of the folding-mast side-plates would have been a secondary, rather than primary cause of the double fatality.

Chris misinterpreted "real possibility" as if the two-piece mast plates were no longer suspect in either crash.

What if a folding mast TAG owner in the USA believes her, and also determines that his rotor blade balance weights are the "safe" ones?
Shall he then fly his machine?

_____

That the ARSA is allowing on case by case basis to flight status is encouraging.

Jeff, since this SD is self-referential:

ASRA may progressively lift this grounding order on a machine-by-machine
basis once the following steps in relation to each machine are undertaken:

. . . one should infer such solely for 1-piece masted machines which are not affected by
ASRA's 1 November 2018 (and still current) SD about 2-piece masted machines.

Those in doubt should confirm with the ASRA Training Manager Jeff Blunt <[email protected]>

AD_2018.01_TITANIUM_AUTOGYRO_TAG.pdf

 

[JEFF TIPTON]

That may or may not be the case. We know that another Titanium went down in Australia. We know it also has a folding mast.

Given that The ARSA apparently missed the balance weight on this machine, one would wonder if the other machine may also have slung a balance weight.

We do not have the answers to these questions, and there will no doubt be additional questions as the investigations progress.

I believe Chris mentioned that the TAG team have a separate entity doing stress analysis of the folding mast design. If the design survives scrutiny, other areas may need to be looked at or it could have been a one off accident. Assembly, fabrication, maintenance, or environment could all play into the picture.

It is still too early to tell.

 

[Kolibri]

Given that The ARSA apparently missed the balance weight on this machine, one would wonder if the other machine may also have slung a balance weight.

I wonder also; it's possible.

Also possible is that the Forrest Beach blade threw out its balance weight upon impact, and not in-flight.


________
Finally, assuming that a single rod was flung out in-flight:

Whilst cutting the rotor blades to facilitate easier disposal, he noticed that a leading edge balance rod was missing.
He finally discovered that the end cap of the same blade was also missing.
The whereabouts of the missing rod and end cap is unknown.

. . . I question the strength of a mast that would break from the imbalance.

Many gyros (even other than Sport Copters) have see full flight rrpm stoppages from rollovers and crashes without breaking their masts.
Which force would be greater: such a ground impact, or the imbalance from flinging out a single rod weight in cruise?

That thought experiment aired aloud, let's not ignore the original (and still remaining) elephant in the room:

improper bolt hole placement of the mast plates​

Jean-Claude and Doug Riley both commented on it. Are they "pedantic, argumentative SB's"?

Regards,
Kolibri

 

[JEFF TIPTON]

This observation raises a real possibility that the balance rod had departed the Forrest Beach Titanium Explorer rotor under centrifugal force during cruise, which – if this occurred – would have resulted in an instantaneous and massive rotor imbalance. Where massive in-flight rotor imbalances occur (in helicopters), it is usual for the rotor support structure to fail almost instantaneously as well because the imbalance forces are so extreme.

There is a real possibility, therefore, that if such a massive instantaneous rotor imbalance occurred with the Forrest Beach Titanium Explorer, then the failure of the folding-mast side-plates would have been a secondary, rather than primary cause of the double fatality.

i would think that the balance weight being slung by the blade striking something I would expect to see damage to the blades leading edge. I do see in the photo that the fiber matrix of the end of the blade is pushed out. Not knowing the weight of the balance, it’s size, or the diameter of the rotors, I would wonder how much inbalance say a one pound weight at at say eighteen feet would cause. Not only would the rotor be out of balance in the rotational plane, but also the blade would now be out of balance in the balance in the chord. Would this also cause a flutter condition in addition to the rotational inbalance? Three inches missing off of a fixed wing aircraft propeller can set up a severe enough vibration to damage the aircraft. Loose enough propeller blade and you might pull the engine off its mounts.

 

[Vance]

Vance, I agree that blade weight loss "may be the cause of the crash at Forest Beach" . . . but that was not my question.
Do you agree with Chris that it "appears to be" the cause? You earlier implied that it did with your "Glad they figured it out Chris."



My point is that ASRA's "real possibility" is not equal to "likely" cause.
This has not yet been "figured out" and it is inaccurate to claim so.

Regards,
Kolibri[/COLOR]

In my opinion no mast can survive a severely out of balance rotor at flight RPM for more than a few seconds so the missing rotor weight and end cap appear to me based on what little information I have to be the likely cause of the Forest Beach accident and the broken folding mast plates the result of the rotor imbalance.

Based on the pictures it seems unlikely to me that the weight loss happened because of or during the accident sequence.

I have not read enough preliminary ASRA accident reports to interpret the language used. It is safe to say they do not use the English language in precisely the same way the NTSB does and they are not likely to have come up with what the NTSB refers to as a "probable cause" at this point in the investigation.

I feel your focus on semantics is a not too subtle way to attack Christine's credibility.

I hold Christine Toves in high regard and she has earned my trust, respect and friendship.

 

[Kolibri]

I feel your focus on semantics is a not too subtle way to attack Christine’s credibility.

I think that she somewhat undermined her own credibility by overstating that ASRA's SD asserted probability (when it did not),
and also solved the Orange crash (which it did not).

I felt her initial post a rush to (false) judgment and a misplaced sense of vindication, especially considering that a new cause for structural alarm had been found,
and more TAG gyros thus grounded.

I've not met Chris, and none of my posts have been intentionally personal.
She is understandably upset and embarrassed by the TAG problems, and clearly doesn't like that I do not share in her over-optimistic reading of the SD.


_________

i would think that the balance weight being slung by the blade striking something I would expect to see damage to the blades leading edge.

Without higher-res photos, it's difficult to tell, but you make a good point, Jeff.
Since the entire rotor assembly detached, and (given its condition) apparently fell rather gently into the water,
I'm now more inclined to believe that the balance rod probably was slung out in flight.

ASRA will likely calculate the forces involved of losing ___ weight rod and end cap at ____ rrpm.
The resulting imbalance was no doubt strong, but I still question the assumption that any gyro mast would suffered detachment.

For example, on 26 March 2017 an ELA 07S in Poland (tail # A12DOB) threw an entire rotor blade in flight.
We had a 3-page thread about it. The Polish accident investigation report is here.
What's relevant here is that the ELA crashed with its mast and rotorhead (with blade straps) still attached.




I cannot imagine a greater imbalance than losing an entire blade from the root. Yet this ELA mast was not broken off mid-air.

Regarding the Forrest Beach TAG gyro crash, if the flung out blade parts caused a sufficiently strong imbalance to break off
the upper mast at the plates, then I believe that the event still points to the weakness of the plates themselves.

Their design remains faulty, and people here more technically knowledgeable than I have stated so.

This is what I hope ASRA will not lose sight of in their investigation.

Regards,
Kolibri

 

[JAL]

I think that ASRA are doing the right thing, they have found a discrepancy in their original investigation and reported it straight away. I think they are doing a great job, they put the facts first then try and come to a conclusion, not the the way around. This information is going to make it even harder for them as I don't know if there is a way of providing a definitive answer to this one.

The fact that this has only happened with the folding mast version suggests to me that the mast broke first and then the blade end caps came off. If it was blade problem then it might have happened to a none folding mast version as well. Not to say that it cant happen but it in my mind there seems to be much of coincidence, however, that not to say it couldn't happen but when in doubt the law of averages is all you have.

 

[loftus]

Hopefully this will get sorted out. Looking to the good that will come out of this, stronger safer rotors and mast. (The mast issue probably by simply eliminating the folding mast option.)

 

[Vance]

In my opinion if a gyroplane rotor blade pitches a nose weight in flight it is a non-recoverable event no matter how strong the mast is.

Something is going to break and in this case it appears to me the plates in the folding mast were the weak point.

 

[Kolibri]

In my opinion if a gyroplane rotor blade pitches a nose weight in flight it is a non-recoverable event no matter how strong the mast is.

Vance, it would seem that would depend on how much weight was lost, and the strength of the respective parts. Not all gyro masts are equal.

Regarding the TAG mast plate design, are you saying that it's at least adequate as is?


________

The fact that this has only happened with the folding mast version suggests to me that the mast broke first and then the blade end caps came off. If it was blade problem then it might have happened to a none folding mast version as well. Not to say that it cant happen but it in my mind there seems to be much of coincidence, however, that not to say it couldn't happen but when in doubt the law of averages is all you have.

JAL, that is some logical reasoning.
Yes, that no blade weights have been thrown from nonfolding masted TAGs is something to consider.

I'd be surprised, however, if the 2018 Orange crash had flung a balance rod.

Regards,
Kolibri

 

[Vance]

Regarding the TAG mast plate design, are you saying that it's at least adequate as is?

Regards,
Kolibri

I don't know enough about the Titanium Explorer folding mast to have an opinion about its serviceability.

 

[JAL]

In my opinion if a gyroplane rotor blade pitches a nose weight in flight it is a non-recoverable event no matter how strong the mast is.

Something is going to break and in this case it appears to me the plates in the folding mast were the weak point.

Vance,

ASRA have not said the loss of nose weights was the cause of the accident. They have simply stated that when the blades were being disposed it was noticed the end caps were missing and some of the nose weights were lost. They do not know when this occurred. I think it is an important distinction and is different to the vibe of this thread that seems to me as suggesting that the blades are the primary cause of the accident. ASRA have just done the right thing and quickly disseminated this information because if it did occur first in flight then the mast failure is probably secondary but that is not their conclusion as yet.

This has only happened to folding mast types and there have been no reports of blade problems with the non-folding types which would, IMHO, still lead to the conclusion that the likely primary cause was the mast failure and the end caps were removed later, either in the air, or hitting the ground or damaged during the recovery process.

Even if the blade inspections of all the grounded gyros does result in discovering a manufacturing defect I still cant see how ASRA will be able to determine this was the cause definitively and so what they have done is cover both possibilities, which is the most appropriate action.

 

[DavePA11]

Vance - You would be a good gyro accident inspector for the FAA. Wonder how you would go about getting such a job...

 

[WaspAir]

https://www.ntsb.gov/about/employment/Pages/Careers.aspx

 

[Vance]

Good evening Jordan,

In my opinion based on very limited information the loss of the blade weight is the cause of the Forest Beach accident.

I don't pretend to speak for the ASRA and they may reach a different conclusion.