Originally Posted by Same again
(Post 10529235)
Thank you for inserting bold type John - very kind of you to point out my dopey error.
I read it again and as far as I can see FH is asserting that there are people here insinuating that the accident was caused by inept pilots screwing up. I am one who suggested that a possible cause of the accident due to the circumstances is one of loss of control due to loss of situational awareness and that can happen to anyone. The only person who has used those terms in FH himself. Paco - note above. That while no human is perfect (hence the repeated mention of "it can happen to all of us", it actually mustn't happen to none of us. |
Originally Posted by JohnDixson
(Post 10529332)
One obvious hypothesis arises from the report along these lines; loss of one tail rotor blade, a huge resultant one per tail vibration which in turn results in the tail rotor, tail rotor head and associated structure separating from the aircraft. CG shifts forward, perhaps beyond the capability of the available at cyclic range to correct etc etc.
That is indeed the first picture that comes to ones mind when reading the prelim. All four blades detached, one completely missing and the TRGB torn off matches all too well a situation where one blade departs. When considering that the tail was found 500ft away and the wreckage was in only 16ft of water plus the Eye witness report of spinning lights (basically ruling out extreme forward velocity which could otherwise explain the tail ending up 500ft away) it is very hard to conceive that all this would be the mere result of the impact. Can't be completely ruled out, but Occam's razor would have a pretty clear verdict here... |
I think I will also send my jury away to gather more evidence. If there is a mechanical failure which cannot be isolated to that particular aircraft or a run of MSNs, it could be a large exercise to potentially inspect the whole 139 fleet.
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At some point if it is reasonably suspected that a Tail Rotor Blade did depart the aircraft and cause the accident....there will in all likelihood be an AD issued to inspect the Tail Rotor for certain defects or evidence of a pending failure.
If I owned some 139's I would consider getting a head start on that possibility and undertake a one time fleet-wide inspection as a purely precautionary action. Not knowing what exactly to look for....just some added emphasis to the existing maintenance actions in place could not hurt. Just Saying! |
Right about the inspection SAS. Be nice to know the TR head and blades hours too. If there was a separation, and they have the TR head hardware, determining if there was a separation and the cause etc will hopefully be straightforward metal fatigue analysis etc, but one never knows. If it goes down this road the NTSB should be out with inspection guidance and/or other related instructions before too long.....you’d expect. To be honest, I’m still very interested in the mechanism resulting in the main blade stubs and their attaching hardware not still being attached to the hub ( yes, I saw the dampers hanging there ). GB: good input and thanks for that data point. Would appear to contradict the hypothesis I postulated. In the case you cited, was any of the tail fin and cone structure separated, as has been reported in this case? |
I know most anything is possible when rotor blades, main or tail, depart the aircraft.
We seem to isolate the events when there is a chance a Main Rotor blade departing could lead to the other Main Rotor blade leaving too....and perhaps one of them taking out a Tail Rotor blade in the process thus kicking off the loss of the other Tail Rotor blades. Hopefully, the missing TR blade will be found and the NTSB can determine what components failed or were catastrophically damaged should all this be caused from a mechanical failure. |
Originally Posted by JohnDixson
(Post 10530618)
..In the case you cited, was any of the tail fin and cone structure separated, as has been reported in this case? There were 13 POB so that is a lot of forward CofG with all those bits missing off the back end. As I mentioned, the aircraft was controllable and a successful landing on the water was carried out with no injuries to any passengers. |
Thanks. Just had a look at that machine on floats in the harbor right after the landing. Whoever was flying did all of the right things-fantastic effort. The question of the controllability/CG would, in the Bahamas case, then rest on whether the separate pieces of that tail cone came off in the air or at water impact. Associated with that question is the physical evidence of the ripped metal edges shown in the rear of the main fuselage in the pictures taken at the recovery of wreckage. The structure in that area has to be quite substantial and strong due to the flight loads and hard landing loads design requirements. Never say never in aviation, but I’m having difficulty convincing myself that the water impact alone did all that. Well, we’ll see, one of these days. |
Originally Posted by FH1100 Pilot
(Post 10528193)
Wait...what? The t/r gearbox separated from the fin? And one of the four t/r blades has not been found? Hmm. I know that a lot of you had leapt to the conclusion that two inept pilots screwed up. And I know it's tempting to use our vast knowledge of helicopters to pontificate on meaningless internet forums so we can prove to others how smart we are... But maybe we shouldn't be so quick to judge? My personal jury is still out on this one.
FH1100, where are you reading that the TGB separated? I can't find that anywhere. |
Originally Posted by noooby
(Post 10530884)
FH1100, where are you reading that the TGB separated? I can't find that anywhere.
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Originally Posted by FH1100 Pilot
(Post 10530998)
Ohhhhh, I dunno. Maybe because the NTSB preliminary report said: "The tail rotor assembly, which was also separated was subsequently recovered." I guess I assumed that to mean the t/r gearbox came off, but now that I think about it, maybe just the tail rotor itself came off and not the whole gearbox? Beats me.
Yeah. To me, Tail Rotor Assy means just that. The Tail Rotor. And their definition of that may also be a bit hazy. How much of the tail rotor? Was the hub left on the output shaft or was the output shaft broken off and still attached to the tail rotor? I've not seen any photos of the tailboom to see what is still attached. And as for the boom being 500ft away from the wreckage..... It weighs practically nothing for the size of it. It should float for quite a while, drifting away from the main wreckage and of course the fuselage doesn't come to rest at the point of impact. It too is travelling at speed. And seeing as I'm here :) I'll address all the posts about the "new" tailbooms that came out after the Qatar incident. They aren't new. The AIN news bulletin is wrong. It says "The new boom will employ a different composite technique and use an aluminum skin bonded to honeycomb, according to one U.S.-based AW139 customer who spoke to AIN." That is not correct. The tailboom always had an external Alloy skin. What changed was the honeycomb. They went from nomex honeycomb to alloy honeycomb. There is an Optional bulletin to change your tailboom over from nomex to alloy honeycomb but boy oh boy is it expensive. The other relevant bulletin is the one that has the external longerons put on (which this aircraft has). That removes all the repetitive inspections and AD's for the boom. There is now a new boom on the 7000kg machines. They wanted to reduce weight and complexity so went with the same honeycomb fin but a conventional boom of sheet metal, frames and stringers, with no honeycomb. Looks exactly the same on the outside. The boom failing in flight is an extremely remote possibility. Same with a TR Blade failing in flight. The new blades have had no issues since coming into service many years ago. Need more info from NTSB to rule out possible scenarios. |
Surely, if a MR blade was shed in flight, the resulting out of balance forces would dislodge the main rotor gearbox attachments.
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In the two 225/332 events....did the gearbox depart either or both aircraft prior to final impact?
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Originally Posted by SASless
(Post 10531415)
In the two 225/332 events....did the gearbox depart either or both aircraft prior to final impact?
If you mean the tragic accident where the top of the main gearbox departed, complete with the rotor head and all four blades still attached, there wouldn't be the same out of balance forces as if a single blade came off. |
Whoever was flying did all of the right things-fantastic effort. That would be Richard Moffat, exceptional pilot that I’ve had the pleasure to crew with. And he did that ditching directing a low time national copilot to correctly manage the throttles. |
You are quite right Shy....but there would have been some very unusual forces for sure....and the question was actually about the stress damage to the gearbox mounts.
My question was not clear enough upon re-thinking it. There was the third crash where a main blade did let go....and I cannot recall if that gear box departed following the one blade. I am looking for that video....but am having trouble remembering where that occurred. Found it......it appears the gearbox stayed with the aircraft but the video is very short and the aircraft falls behind a building immediately after the blade separates and the rest of the rotor head departs. |
Noooby, the report reads: ”The helicopter was found inverted and the tailboom was separated from the aft fuselage and was recovered in multiple pieces.” This begs an explanation for the “multiple pieces “. |
Watch this video.....and count the pieces!
I wonder where the tail rotor blades wound up after this tragedy? |
Does anyone have the certificate details of David Jude (the CPL pilot)? I've been trying to find his cert number but it isn't in the prelim.
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Latest letter issued from Leonardo, does not appear they think there was any mechanical failure !!
Following AW139 accident that occurred near Big Grand Cay Island, Bahamas on July 4th, 2019, Leonardo Helicopters immediately dispatched a team to offer support to the recovery and investigation and continues to work closely with the Investigating Authorities. At this point, Leonardo Helicopters do not envisage the need to take any airworthiness actions as a result of present investigation outcomes |
At "faa.gov", you can search the data base for his license details.
I just did so and exactly one entry using "David Jude" is returned. |
Originally Posted by SASless
(Post 10532009)
At "faa.gov", you can search the data base for his license details.
I just did so and exactly one entry using "David Jude" is returned. |
Excuse my ignorance, but what does the C/ mean in the FAA C/AW-139 type rating, and what does the A/ mean in the A/AW-139 type rating?
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We have seen another Helicopter Manufacturer issue such public statements in the past.....and it later turn out they. had a major problem in the design of their aircraft.
How much credence can we put into Leonardo's Statement? If it is credible and based upon the results of the examination of the wreckage.....then that would point a finger directly at the Crew as the weather was benign. Has any more information surfaced about their backgrounds, training, medical history of the crew, and their 139 experience been made public? Anything that would put into question their fitness for that particular flight or climatic conditions (dark, over water, lack of horizon....etc). |
Originally Posted by twisted wrench
(Post 10532005)
Latest letter issued from Leonardo, does not appear they think there was any mechanical failure !!
Following AW139 accident that occurred near Big Grand Cay Island, Bahamas on July 4th, 2019, Leonardo Helicopters immediately dispatched a team to offer support to the recovery and investigation and continues to work closely with the Investigating Authorities. At this point, Leonardo Helicopters do not. envisage the need to take any airworthiness actions as a result of present investigation outcomes |
Originally Posted by gulliBell
(Post 10532026)
Excuse my ignorance, but what does the C/ mean in the FAA C/AW-139 type rating, and what does the A/ mean in the A/AW-139 type rating?
C/ = CPL P/ = PPL (source FAA.) |
There is another very hypothetical possible cause factor which fits the little pictorial and other public media and preliminary report evidence available. Background: the AW139 rotorhead incorporates leading edge pitch control horns i.e., the push rods are attached on the blade leading edge side. Same as the CH-53E. The 1996 CH-53E fatal accident on the first hover of a standard production machine was traced to a bearing failure ( caused by a manufacturing defect in the supplied bearing ) in the rotating swashplate. One can easily imagine the rotating swashplate slowing down and the effect on rotor control. Those words imply it happened gradually, but the final bearing failure happened quickly and part of the result was that the blades chopped the tail off, while the remainder of the machine descended vertically from the 150-200 ft where they had been hovering. I had been walking toward the rear of the pilot office ( which has a somewhat cut-off view of the field ) and heard three distinct thumps, turned around and caught a glimpse of the machine before it disappeared behind a storage shack. The rear tail section was separated. I’d imagine the NTSB will as a matter of course look at the swashplate bearing and ensure it still moves freely. PS: the reason I used thee term “very hypothetical” is because the difficulties involved in design/manufacture and QA on a huge swashplate bearing as on the 53E are quite different than on much smaller vehicles. |
So if you have a CPL with C/AW-139 type rating, and then you get an ATPL, the type rating will be changed to A/AW-139? Even if you didn't do the ATPL practical test in a AW-139?
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Could it be that the reason for the CPL Type rating is the applicant had insufficient hours to qualify for the ATPL or had not passed the Written Exam for the ATPL, but passed the same Practical Test (Check Ride) as he would have had he the ATPL?
Perhaps someone currently conducting FAA Type Rating practical tests can explain how the procedure works so we can all understand the nuances of Type Ratings under the FAA system. Ask and you shall receive.......from a friend still active in the business out in the wilds of Louisiana....still doing this stuff. \Training under part 142 follows specified standards. The Training Curriculum is listed in the Training Center Manual approved by the FAA assigned TCPM All type-ratings are issued to ATPL Standards and follow the relative Practical Test Standards. The PTS are to become amended to ACSs and follow new standards in accordance with 61.58 Proficiency Check requirements and applies to ALL type ratings. |
Originally Posted by twisted wrench
(Post 10532005)
Latest letter issued from Leonardo, does not appear they think there was any mechanical failure !!
Following AW139 accident that occurred near Big Grand Cay Island, Bahamas on July 4th, 2019, Leonardo Helicopters immediately dispatched a team to offer support to the recovery and investigation and continues to work closely with the Investigating Authorities. At this point, Leonardo Helicopters do not envisage the need to take any airworthiness actions as a result of present investigation outcomes |
I think this ones just going to be as simple as the flew it into the water.
Hard to take it for some but **** happens. |
Originally Posted by MS29513-017
(Post 10533218)
I think this ones just going to be as simple as the flew it into the water.
Hard to take it for some but **** happens. |
Without going into why I ask this question.....but is there reliable/credible information to describe the reputation/record/quality/complaint record of Cloud Nine LLC's operation and business standards?
I have found one FAA Action taken on "2014WP230061" dated 01/18/13 which resulted in the Suspension of Cloud Nine LLC's Operator Certificate (no Fine/Penalty shown) with a closing date of 08/01/14. |
Nothing further? Was expecting to have heard a bit more by now... |
Well, the 139 hasn’t been grounded and there haven’t been any ADs or SDs issued. Read into that what you want... |
Exactly. All this BS about the tailboom being found 500 ft from fuselage (according to whom? Not NTSB), and a t/r blade separating in flight, and an eyewitness 1.6 miles away (at night) counting the fuselage making THREE ROTATIONS TO THE LEFT. I think after almost 2 months of NTSB and Leonardo poring over dynamic components and no emergency AD, we know what happened.
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Originally Posted by UKExpat
(Post 10553949)
Nothing further? Was expecting to have heard a bit more by now...
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Spray, The lights wet from right to left, not the fuselage. If tail lights that is consistent with loss of tail rotor thrust. After the early problems with the t/r blades the new blades are probably so over designed that a repeat is not even being considered. If the data/wreckage shows no drivetrain issue you are down to t/r bird strike or FOD as the likely cause. |
Just throwing this out there. Has there ben confirmation of who was occupying the pilot and co-pilot seats?
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Originally Posted by garsr1
(Post 10554156)
Just throwing this out there. Has there ben confirmation of who was occupying the pilot and co-pilot seats?
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