R-22 ROTOR SEPARATION? Florida Photo

[fly911]

http://i135.photobucket.com/albums/q140/fly911/helo3.jpg

Man killed in helicopter crash was experienced pilot | TBO.com (http://www2.tbo.com/news/news/2012/dec/01/5/missing-helicopter-pilot-identified-rescuers-resum-ar-578735/)

The pilot whose helicopter crashed into Tampa Bay on Friday afternoon near Apollo Beach was an experienced pilot who was certified on multiple aircraft, including large commercial passenger jets, according to a statement released by his family.

John Lawrence Ward, whose friends called him Larry, held both U.S. and International airline transport licenses and was a licensed helicopter instructor, according to the statement.

“He had just celebrated his 60th birthday on Thanksgiving,” according to the statement. “Larry loved flying.”

The statement said Ward’s wife, Karen and friends were shocked by the tragedy as Larry was known as a meticulous pilot.

“Information available suggests that this may have resulted from mechanical failure,” according to the statement.

The Wards have been residents of Davis Islands in Tampa for more than 20 years. “Karen appreciates the concern expressed by family, friends and neighbors regarding Larry's death,” according to the family’s statement.

Ward took off Friday afternoon from Tampa Bay Aviation for a flight in an R-22 helicopter. The weather was good and Ward, a 1974 graduate of the U.S. Naval Academy with more than 20 years experience as a pilot with American Airlines, was flying about 75 yards above Tampa Bay.

Around 3 p.m., the helicopter crashed into the bay when a rotor apparently malfunctioned and separated from the helicopter, according to witnesses.

The helicopter sank into the shallow waters of the bay a few hundred yards offshore and quickly sank.

Crews immediately started searching for Ward. They found the helicopter using underwater sensors but were not able to find Ward’s body or salvage the helicopter by nightfall. The search resumed this morning and divers with the Hillsborough County Sheriff’s Office soon found Ward’s body at the site of the crash.

The National Transportation Safety Board and the Federal Aviation Administration will conduct the investigation into the cause of the accident.

[P6 Driver]

Clicking on that link gives me a BIG anti-virus warning about not going to that site...

Good luck if you fancy trying it yourself!
:)

[g0lfer]

Worked ok on my iPad.

[Aesir]

No problem on my PC.

That accident really sucks :uhoh:

[Anthony Supplebottom]

How on earth can the main rotor simply separate from the rotorhead?

This is incredible.

[topendtorque]

site opened for me OK too. but sure as hell gives ones the heebees straight up.

"a licensed helicopter instructor"

AS, Usually the only way they can separate and not at the same time damage tail boom is by mast bumping, from low G flight such as a pushover from the top of a cyclic climb.
Hard to imagine that from a flight instructor, very hard.
Unless there was a preexisting damage, the investigation would quickly establish that though.

The only other way is that the mast became separated in the xmon (nut comes off bottom of mast) and that has happened a couple of times but mods should have fixed that on all aircraft by now I would guess. That could happen and leave the mast fairing in place.

I saved image and blew it up to reveal what looks like mast fairing still in place. I don't see any flocks of birds in the photo.

Sympathies to all concerned.

[Heliboy68]

This is not an uncommon scenario with the R22. NTSB report SIR-96/03 makes very interesting reading into the "phenomena" of R22 accidents in apparent straight and level flight.

[Vertical Freedom]

Rest In Peace my sincere condolences......

Welcome to the Crapinson Flimsicopter no surprises here very sadly a regular & common event.:yuk::yuk::yuk::{:{:{

Happy Landings

VF

[Nigel Osborn]

Looking at videos of the R22 cattle mustering in Oz, I'm amazed there are not more of these types of accidents. I know some years back that not all the flight hours were recorded to "save money". The good old tough Bell 47 could get away with that but it appears the R22 can't. So sad for all involved.

[Sir HC]

Nigel, surely you're not so naïve as to think that those days are gone?

As for this accident, I'd be very interested to hear what happened if it's not a result of a low g maneuver, very sad for everyone involved.

[fly911]

I believe that there is a minimum solo weight on the R-44 that could effect stability. I'm not sure about the R-22. A very experienced pilot. Sad to see this happen.

[anti-talk]

Doesnt look characteristic of low G / Mast Bumping as the tail looks completely intact.
I wonder if it threw a blade - I saw a 22 roll over from the hover a few years ago inverting the aircraft with one blade completely intact about 600 ft from the wreckage.

[flight beyond sight]

VF

I am truly saddened by such a crass remark coming from somebody who until now I respected for their skill and knowledge.

[Shawn Coyle]

Evidently if the flapping hinges start to act up, things can get out of hand pretty quickly.
Anyone have more info on flapping hinge failures such as sticking / jamming?

[Gemini Twin]

I'm with you VF, these things are a disaster. Sorry FBS if this offends you.

[Dennis Kenyon]

Until recently I would have been surprised that an experienced FI could make the mistake of a swift cyclic reversal following rapid flap-back in turbulence. That was until I found myself co-piloting with an experienced SH 300C owner. Following a good general handling session, I sat back as my pilot lifted off with excessive aft cyclic. As the T/R approached the surface, without thinking I reacted immediately by ramming the cyclic forward. The day was saved but thinking back I could see that had I been R22 airborne, such action would probably have resulted in a severe 'mast bump' to say the least and more likely caused a M/R - mast separation. Sobering thinking time! DRK

[Vertical Freedom]

Namaste flight beyond sight

Sadly that was no crass remark. As I have known well 2 Pilot's killed by the Robi & 1 almost. A close friend who is very senior Engineer & Pilot refuses to fly them point blank, reason he gave is; I have Family, a Daughter & I am not going to fly such a known widow maker as he had rebuilt too many & is disappointed in the flimsy construction & too many blade delaminations. :ugh::suspect::{

Happy Landings always :D:D:D

VF

[hillberg]

:rolleyes:In late 1987 I was flying an R-22 600 agl 80 kts when it rolled to the right 90 deg uncommanded.:eek: It was a shocker I added a little aft cyclic and the almost low G became a banking turn to the right, I thought it was a mountan rotor from the hills near by, After reading the special report I turned white. WTF over,:=never will I think twice of what it might of been:O

[mhale71]

I would vote against a single-blade-throwing scenario, as the aircraft is peculiarly intact in the photo. With the massive imbalance and rotation from one blade departing , i would expect to see a buckled or fractured tail boom, as well as the whole upper portion of the fuselage being ripped open from the transmission ripping itself out.. (think back to that squirrel crash in nz last xmas)

While i cant speak from experience myself i also would have thought mast bumping would come with tail and fuselage damage... as well as it being less likely from a more experienced pilot. Although only speculation; it might be a worthwhile guess that the aircraft had a previous mast bumping incident that went unreported, and may have damaged the mast internally.. for it to later fail in the cruise on this flight.. (in a positive G state.. pulling the rotor section away from the fuselage without impacting it)..

Very sad indeed.

[blakmax]

I'm almost with you Mhale71. I have been directly involved in one crash of an R44 and in that case when one blade failed catastrophically the other blade suddenly carries all the load and rises. In the case I dealt with, the failed blade did not separate entirely so the spar which was still attached flailed the tail boom and the boom failed. There was significant evidence of disbonding (delamination?) within the blade structure (confirmed by the NTSB) and the IIC concluded that this was the most probable cause of the crash.

I do not see any evidence of any remnants of either blade in the photo and I do not see any distortion of the boom. So, unless there was a simultaneous separation of both blades, I think the failure is further down the mast or in the attachment of the rotor head to the mast. Anecdotal reports indicate that cockpit strikes may also occur after failure of one blade. I do not see that in the picture.

Regards

Blakmax

[gulliBell]

...the eye witness in the video said "the white rotor popped off and flew up..."

[blakmax]

Thanks gB. I missed that. It does change my perception and increase my level of concern. I'm still not sure that loss of one rotor blade would lead to no fuselage damage and separation of the other rotor blade.

I just hope this is not yet another case of disbonding leading to blade failure and another loss of life. I'll wait for the initial report before further comments, but I have been waiting for three years for one airworthiness authority to release the report on the investigation I was involved in. It is so frustrating to sit aside and know of a significant issue but not being able to openly discuss it without the legal cover provided by the final report.I stress that my concerns may not be applicable in this case, and I certainly hope that is the case.

Regards

Blakmax

[ShyTorque]

A truly tragic and horrific accident. It looks like a classic case of the "Jesus nut", or Robbo equivalent, failure.

[topendtorque]

I'm pretty much with you too M'hale as you would have seen. I'd be thoroughly cross examining historical flights pilots.

I checked the local WX but from here can't seem to go back further than the 1st but the photograph of the foliage and WX trends show nothing our of the ordinary at all, 5 to 10 knots fair etc.

I don't believe that a mast bump has to take out the tail boom and I agree with Blakmax that a bad flight condition on one blade could have imparted strong enough forces to cause the mast bump. Against that the eyewitness should have also said something like this, "even though we were seeing it what really got my attention was a really increasing swishing sound before the thing flew off"

The witness also said it "flew up" indicating an aerodynamic stability of some sort of the rotors, which wouldn't be the case with a major debond I don't think.

We had a '47 once with a mast cracked severely. It exhibited a very strong vibration and was cracked a third of the way around and nearly 1/8 inches wide at center of it.We put that down to constant over controlling, little or no corrosion evident from memory. The A/C was fitted with a no bar kit and the crack was just under the mast rod end clamps.

So I guess I am getting around to saying that if there was a pre-existing crack that it should have exhibited some form of vibe, but then again it could well have been very early stages. Another issue is the proximity of the ocean and whether there may have been advanced corrosion.

Certainly one blade off I think would take out either or both cab and tail boom in collateral damage.

The Aussie air force 205's from memory with their mast bumps years ago didn't have collateral damage, I could be wrong there.I used to know one of the eye witnesses to the second one and he didn't mention it.

Dennis, believe me you will need weightlessness to do damage; any sort of violent control inputs whilst you have positive pendular weight will just force the A/C to just follow the cyclic. A mate of mine and I were chewing this last night, his words were, 'You would have to think that after all the hundreds of thousands of hours of mug pilots and good mustering drivers that a simple problem like over controlling would have shown up yonks ago.'

Finally I will devoutly say that these things are not flimsy. Some of the components over the years have had their faults, the flimsy stainless steel skin on those blades being one, but they were only flimsy when idiots ran into things, quite solid enough to fly with and do all sorts of hard maneuvers with. Perhaps your engineer mate VF is talking about A/C that are flown over hours, if so it's non valid argument. Very many are over flown for sure.

These R22 A/C have had many beef up mods, 90% of which I am reliably informed emanate from North Queensland where they were consistently overflown.

So, Frank now has an aircraft design far superior than is needed should people fly according the 100 hour and AFM book.Lots of the blades failures have been shown to have just simply been so overweight so often that it is bleeding obvious someone will get hurt.

I've tried to hurt them often and toughest ride I have had for a long while was today, 42 degrees outside the moo cows being particularly not fond of such heat and some bloody cane toad had crawled into the machine some days ago while it sat outside with doors on, stink that bastard.

cheers tet

[henra]

While i cant speak from experience myself i also would have thought mast bumping would come with tail and fuselage damage...


Hmmm, I'm not 100% sure but when I look at the picture closely I have the feeling that the cab might be missing at least partially.
Even if it was a doors off flight I seem unable to see the solid part of the cab that is normally underneath and a bit in front of the pylon.

Therfore I wouldn't rule out a classic mast bumping with severing the cab. In that case the tail boom might stay on unscathed. I'm pretty sure I remember cases before where that happened.
In that case we could only pretty much rule out LRRPM induced Mast Bumping because that usually blows the Rotor disc backwards leading to the Robbie- Cut.

[Matari]

Additional information here: Robinson R22 BETA II, N2626N: Accident occurred November 30, 2012 in Apollo Beach, Florida - Aviation News & Events (http://kathrynaviationnews.com/?p=118133)

The helicopter was recovered from the bay 2 days later. The engine and rotor mast remained attached to the airframe. The rotor hub remained attached to the rotor mast; however, both spindle assemblies and their respective main rotor blades had separated from the hub and were not recovered. The tailboom separated about 6 feet from the transmission and the tailrotor remained with the tailboom. The rotor hub was retained for further examination and a further search for the main rotor blades was planned.

(bold mine)

[topendtorque]

Boy oh boy oh boy.

So much for witness statements.

We still don't know whether the spindles themselves or the hub failed, which I think I am right in saying would be first time ever for either and in either which way case I would say watch this space very closely or;
whether the spindle bearings failed in which case - I become mute.

[Gordy]

I am right in saying would be first time ever for either and in either which way case I would say watch this space very closely or; whether the spindle bearings failed in which case - I become mute.

Hmmm... I think you would be interested to read some of the initial comments to the request from the NTSB to ground the R-22 back in 1993..... They are all still there. I will leave it at that... Google is your friend.

[500e]

The tail appears to be complete in the photo was it damaged by blade & broke on impact or did the water impact cause the break.

[topendtorque]

both spindle assemblies and their respective main rotor blades had separated from the hub This what has got me? It seems quite clear and presumably written by a helicopter experienced person. It may be of course that it was the blades, outboard of the blade spindle housing which failed, which is where all other blade inboard failures have occurred. If it was a -2 blade and one failed, I guess it not unreasonable for the other to fail immediately given the massive torque spike. That is, if it already had a progressing fatigue crack.

I note in this link (http://www.atsb.gov.au/publications/investigation_reports/2003/AAIR/pdf/aair200302820_002.pdf) where there is an analysis of similar failures done by OZ ATSB that on none of the Aircraft mentioned did they carry out an inspection of the second blade to see whether there was evidence of fatigue crack commencement.

Except for the first, which was a -1, the rest are -2.

Thanks Gordy for this one (http://http://www.rotorshop.com/sir9603.pdf)which I think is the one you refer to, with 31 accidents. All appear to relate to being either mast bumping or low RRPM causing blade stall, or unexplained M/R divergence.

I still cannot find evidence of either hub, spindle or spindle bearing failure.

Cheers tet

[anti-talk]

This is very interesting, we had a 22 Roll over in the hover about 3 years ago that appeared to throw a blade - it was thrown well clear of the wreckage with no bending or discernable damage, the mast sheared at the gearbox and then the mast wrapped under the machine causing a pre impact fire due to ruptured fuel tank (as the mast cut through it)
Fortunately both occupants escaped the wreckage , the pilot stated he didnt grab a skid (dynamic roll over) and the machine literally inverted itself very violently (both occupants lost their shoes)
We were convinced this was a blade separation (query bolt failure??) we recovered the blade with hardly and damage, the Hub broke in two and the bolt was no where to be found.
As a result everytime the blades come off the machine we now replace with new bolts (never did like the 'stretching' idea.)
The local FSDO felt there was some mileage in the blade seperation idea but the NTSB had no appetite to investigate further due to there being no injuries. We retained the hub and I still have it to this day.

[topendtorque]

Thanks, anti-talk, you have answered one query we all used to have that being, was there ever a chance of pilot survival in the neck area if one of a two blade system departed. Probably depend on a lot of factors though, actual cabin weight to help cancel reaction or whatever.

But regarding your hub, any chance of posting some photos of it?

NTSB had no appetite to investigate further due to there being no injuries.Yes that is a galling issue, not just NTSB but it seems most all agencies have the same retardence of mind. It would be very wise to use their investigative resources in many areas. Too easy to cut back claiming their own financial resources limits, which of course means to fix it we need to go to the Ministers responsible, a tough task most places.
cheers tet..

[fdr]

Anti talk: can you pass on any photos of that head to Shawn, blacmax or me please?
AUS mustering: loads in the outback mustering are generally quite low, more concerned with the cycle records, given the value of S-N curves out at 10^7...

Photo of the descent show apparently that there has been a blade fuselage strike, the upper canopy area is missing, which is consistent with a loss of one blade and the track of the remaining blade. Following fuselage impact, that remaining blade is not going to be hanging around, so may not have hit the tail boom before departing fix.

Coning hinge... the tension on the coning hinge balance to the teetering hinge is important. If the blade starts flapping at the coning hinge instead of the teeter, it imposes very high strains on the blade, and a failure of the blade itself has been recorded in the UK (failed 3/4 through from TE in 20 minutes). Vibration is very high with such failures, no doubt that you are having a fun day. I have had a coning bearing eat itself in 5 minutes, and it was a rapidly decaying condition. I think the mfr would expect this to last longer in general, my event was a 44, and it was 5 minutes. On preflights, look for aluminium oxide (gray dust) around the teeter and coning bold spacer/washers.

Personally, have a query around the +ve delta3 configuration that occurs if the blade flaps at the coning hinge, but some very well respected aerodynamicists consider that not so unusual, gets my attention nonetheless.

RHC is a "finely" designed machine, much stronger than you would expect, and still a great machine to fly. It does get attention with the question of divergence from time to time. :ooh: The concord event is probably the most perplexing case out there still on divergence.

Mast bumping is mainly a low g event; at low advance ratios, or hover, you may get a tail boom strike.. but I would be surprised if you get a mast bump straight off with rapid reversal of controls. (don't try this at home... :| :=). The mast stops are very good indicators of contact from the inner land of the hub, the preflight of a RHC is worth every second. The rotor system is intolerant of abuse, but is able to still be flown within an impressive envelope with due care to the basic dynamics of a teetering head.

FDR

PS: the report will be very interesting to look at. The general modes of failure are pretty well established and the physical evidence will speak to the specific failure.

[anti-talk]

Next question for operators, how many Rotor Hubs are you getting back from RHC at 2200 hrs and how many are they are condemning.
Lets take a straw poll?

[HeliHenri]

The two main rotor blades from this fatal R22 accident still missing. Robinson offers reward for blades :

Robinson $2,000 reward (http://robinsonheli.com/bladereward/)

[Anthony Supplebottom]

Far be it for me to be cynical about this but does this equate to an equivalent value of $1000 per aircraft seat/passenger?

Does this value express Robinson's motivation to stimulate search incentive?

Does it also express their value of accident investigation?

Just asking.

[topendtorque]

Dear oh dear.
Well this is what the preliminary report says

The rotor hub remained attached to the rotor mast; however, both spindle assemblies and their respective main rotor blades had separated from the hub and were not recoveredand, they are showing pictures of the bolt hardware.

Do we assume because of that the bolts intoto are missing? what is remaining? Any evidence of bolt breakage and twisting off of the hub? I don't have any idea how malleable the hub is and whether it could bend to accommodate such movement.

My gut feeling is that it would be extraordinary for the spindle hub-end to break before the retaining bolt, but I'll happily bow to wiser metallurgical heads.

A seaside residence and unchecked corrosion on steel bolts may have an answer, but gee whiz, surely not that bad and on both bolts????????.

[Matari]

Here is a photo of one of the blades (can't find if this has been confirmed by NTSB). Note the big chunk out of the trailing edge near the trim tab. Spindle looks attached but hard to tell from this pic what part on that end might have failed.

From this site:TreasureWorks - Helicopter Blade Recovery - TreasureWorks Forum (http://treasureworks.com/forums/32-shipwreck-hunting/10548-helicopter-blade-recovery#10587)

http://i529.photobucket.com/albums/dd332/bulamatari/R22BladeTampaBay_zpse80c48d0.jpg

[lelebebbel]

Looks to me like there is a rather large part of the rotor hub still attached to that blade, including the blade bolt, or at least part of the bolt (to the left of the blade in the photo).

Edit: This is what I mean

http://i.imgur.com/rHstG.jpg

[blakmax]

Matari, I note the segment of blade held by the person in the picture. From initial observations I do not see any adhesive on the LE foaming adhesive bond surface. This means one of two things: 1. the adhesive was never bonded along that face or 2.(more probable) the failure was through the core. Closer investigation would tell the actual location of the failure.

Is that TE separation related to the crash? My initial thoughts are that it is not. The spar appears straight so that suggests that this blade has not impacted the cockpit or boom, which I would expect if a segment of blade had failed at the start of the crash. It is possible that the other blade has different damage patterns.

My suspicions fall on the close up discussed by leleb(etc.). If you look at the very left of the blurred image at the very end of the remaining structure, you will note that the left side appears bright, but the rest of the surface appears dull. Rapid fracture surfaces are usually brighter than regions where fatigue cracking has occurred. I stress that this is only a suspicion. Closer inspection would be required.

I'd love to make comments about the look on the guy's face but in respect to the deceased, it may not be appropriate to make light fun under the circumstances. RIP.

Regards

Blakmax

[Matari]

Blakmax, agree with your assessment.

Here's what we know so far:

1. One blade impacted the cabin, but probably not the blade shown here.
2. The clean 'cut' of the honeycomb on this blade looks more like structural failure vs. impact damage.
3. The spindle remained attached to the blade root.
4. There appears to be mechanical failure of the coning hinge attach point to the M/R blade, but that could be due to water impact (just guessing here of course).
5. So, possible failure of M/R blade honeycomb resulting in impact of second blade with cabin and possibly tailboom, liberation of the blade due to imbalance and structural failure, loss of aircraft control and impact with water.

The second blade will be interesting to see. The treasure hunter shown has probably already found it.

RIP, sad story.

[hillberg]

Coning bolt failure,piece of hub trailing side,tusk on spindle bent inboard, No leadind edge damage, outer bits of honeycome & skin ? cleaved out by the other blade before it also launched from the mast?,need to see the whole batch of pieces to the cause,Spindle crack AD with the fiddling of the suspected parts contribute for the bolt failure?

[topendtorque]

I don't agree with Matari's depth of knowledge.

To me the cabin and bubble did still look in one piece and the tail boom if broken prior to water entry can easily be explained by immediate engine over speed causing whirl mode in the T/R drive shaft and breaking the tail boom right where they said it was broken. That is easy to see, have a look inside the tail boom, there will be evidence of the out of balance shaft. hitting it, bearing hangers torn off etc.

I don't agree that one blade hit the other, a) there is no pictorial evidence so far and b) that would also have meant at least half a turn after one departed with the consequent out of balance effects, not yet visible in the cabin photograph..

The thing that is really striking to me at the moment is that the threaded end of the blade bolt appears to be visible (under the rope).
If that is the case why did the nut detach and leave the rest of the hub behind - or elsewhere?

I cannot see the thread sufficiently to gauge its integrity.

Were both bolts over stretched at some assembly in the past causing damage to the threads, does or can the procedure of stretching leave the threads, hanging on the edge?

That may be a plausible explanation of both bolts at once?? It may explain why when the blade in the picture departed it did so rearwards until the nut less bolt cleared the other side of the hub, then it simply broke off the hub portion - still attached - because of rearwards leverage.

See that sort of thing in machinery all the time.

I sincerely hope they can find the other blade it should be easier now, but they might need a few more dollars to help.

Is anyone close by that can report on that?

tet.

Someone should have given me a tune up, if it is the bolt that I refer to of course it would have to be the nut in the left hand side of the photograph and presumably the trailing edge as the bolt is supposed to be installed with head on the leading edge and which looks totally different from the other end in view.

Meaning if it is the bolt the head of it is missing??.

[hillberg]

Nut ,piece of hub,pitch link,mostly intact blade,a wipe mark next to the drain plug,chunk of blade gone, tip at the very end looks like a good dent, How deep was the water? did blade drop in the water & hit the bottom of the sea?
strange. over streched bolt? head scraching continues.

[Matari]

topendtorque,

My depth of knowledge on the R22 is very limited, and my knowledge of this puzzling accident even more so. I'm just speculating, not knowing any more than anybody else here. I really hope they find the second blade and some answers, pronto. Every R22 driver out there deserves a fast and thorough investigation.

[helichoppers]

Just to throw something else in to the pot..

We had an R44 Raven II that fortunately whilst sat in the hangar and not flying suffered a Blade Bolt Failure!

We returned to the machine after it had sat for a weekend to find a thrust washer sitting on the hangar floor! The full horror then dawned as you looked up to see one of the main Blade bolts sticking out from the Hub. If this had failed in flight and not whilst sat with the full weight of the blade on the droop stop I am sure the bolt would have totally departed from the aircraft along with the blade etc and you can imagine the rest....

The bolt was sent to our local CAA for inspection who then sent it to the FAA via Robinson, the opinion in the end was that it was a one off caused by Hydrogen enbritellment of the bolt and was not considered to warrant further investigation. The bolt had a total time of 80 hours from new.

I appreciate this was on an R44 not an R22 but the bolts must go through a similar manufacturing process??

I can email pictures if you PM with an email address me as I cannot seem to get them to insert to this post.

[Thomas coupling]

Helichoppers: this is so freaking scarey! What is more scarey is that neither the FAA or the CAA mandated for a supplier check on QA or a mandatory change to another supplier. Do you mean to tell me, you simply replaced the suspect bolt with another from stores and went flying!!!!!!:mad:

[Hughes500]

TC
Best post i have seen from you;) It is at this point one wonders what is the point of The CAA. 3 years ago whilst engineers doing an exhaust valve guide check discovered 1 collet missing and only half the other one, ie valve about to drop into engine. On futher investigation engine overhaul shop had put wrong valve into engine. Spoke to CAA who were not interested, at that point I gave up with the system:ugh:

[Gemini Twin]

The bolts are usually made in batches if one failed due to hydrgen embrittelment I would check the whole batch. The post treament bake process may have been missed.

[anti-talk]

Would be very interested in further info re the embrittled bolt (pictures), Im convinced our accident was bolt failure but no one seems to want to investigate it!
Fortunately the machine was in the hover when it 'appeared' to throw a blade and no one was killed.
We now as company policy regularly replace the blade bolts and NEVER re use them.
As an operator with 14 RHC aircraft I really would like to know the bolts are good!!!

[500e]

We have maintenance schedules, manuals to tell us exactly how to do things, every item has to be made, tested, approved, with a paper trail, APs are certified & the FAA CAA say not a problem regarding a bolt that fell to pieces, makes me feel really safe in the knowledge that the regulators are on top of problems, surely at least the batch should be recalled at no cost to owners then an in depth examination made of both the batch & the manufacturing process\ facility.

[helichoppers]

TC

The aircraft was grounded pending investigation, once all the relevant authorities were satisfied we changed all the bolts and nuts for new ones, and the aircraft has flown without a problem since. We suggested that a recall was carried out on the bolts of that batch and that as a matter of safety the ones in service were replaced or inspected, that fell on deaf ears! what more can you do if the authorities and manufacturer wont do anything?

We were told there had never been any reported incidents of bolt failure but it appear there is more coming out in to the open.

HC

[500e]

Sorry for my last post I forgot the rules, it is all ways the owners problem never the regulators or manufacturers, perish the thought, I wonder what the response would have been if it had happened in flight, another low G accident I suspect.
anti-talk
Was your bolt broken or damage to great to access initial failure glad it turned out not to bad.
Any official report done?

[anti-talk]

Yep NTSB investigated by 'telephone' as no one was hurt :ugh:
Bolt was never recovered but the hub was scored on the inside and subsequently fractured, have the hub (well not the part that would have had the bolt attached). Whats left of it that is!
The guys were incredibly lucky as they were in the hover, the rotation was so violent they both lost thier shoes in the impact.

[John R81]

I had understood that once these bolts had been subjected to appropriate torque they should not be re-used. Was I wrong in that belief?

[anti-talk]

Yes John you are, however we DO NOT re use them as a matter of internal policy

[Hughes500]

Just had a conversation with a friend who works part time in our industry and as a quality auditor for a large utility company. They have had a major issue with hydrogen embritlement in bolts holding gas pipes together !
They are having to withdraw bolts as some fail on torque up, some at a few days some at a few months. When i told him the story of bolt failure and it being a one off the response was initially stunned silence followed by " the quality control of the bolt manufacture has failed in which case the whole batch of bolts that that bolt came from will be affected, at the very least someone needs to get into the manufacturer to check on the process "
Best of luck if you fly one of frank's products :uhoh: At this point I dont know why I bother to have a Safety management system for my company when the manufacturer/ competent authority ( perhaps that shold be incompetent authority) obviously isnt interested in safety:eek:or shold that be :ugh:

[topendtorque]

When installing the procedure is to "stretch" the bolts to between .015" and .017". The manual carries a warning that overstretched bolts can lead to a catastrophic failure.

Indeed. Especially IF the bolts were more brittle and thus less malleable than usual.

" the quality control of the bolt manufacture has failed in which case the whole batch of bolts that that bolt came from will be affected, at the very least someone needs to get into the manufacturer to check on the process "Either checking or withdrawing a batch would be far cheaper than a game of chance.

[Helinut]

That is just scary, beyond words.

Russian Roulette anyone? :ugh:

[Good Vibs]

Russian Roulette with one round in a pistol I guess.
Not a Revolver!

[lelebebbel]

Lets keep to the known facts for now, shall we?
Has it been confirmed that this was a bolt failure? No.
Has it been confirmed that this hypothetical bolt failure was caused by a faulty bolt, not an installation error? No.

By the way, there is nothing scary as such about "stretching" a bolt. This is how bolts work. In fact, measuring the stretching is one of the most accurate way to ensure the proper pre-load on a bolt. When you are tightening a bolt with a torque wrench (or any other wrench), you are also stretching it. Basically, every bolt holding anything together on any helicopter is stretched.
Measuring the bolt length rather than the torque is just a more direct, more accurate way to ensure the correct preload has been applied.

[topendtorque]

Hi Lebl

Can you see the head on the bolt in the photograph?

cheers tet

[Matari]

Another bit recovered from Tampa Bay. Anybody recognize this part?

http://www.treasurenet.com/forums/attachments/shipwrecks/727036d1358473394t-mag-needed-asap-helo-crash-tampa-bay-img_0314.jpg

[RJC]

If the code A028-7 is a part number then, I think, is the frame to the rear of the main fuel tank.

[topendtorque]

Not in parts book, so I guess it cannot be bought and also guessing that it attaches to the seat hinge which is A928 - 5. part of the seat mount structure. Perhaps easy to imagine it being torn out in a fast nose first water entry.

[lelebebbel]

Can you see the head on the bolt in the photograph?

No, the photo is pretty poor quality, and there is stuff in the way. So I can't tell for sure if it is there or not. Even if the bolt is broken, that doesn't automatically mean it was faulty from new. Maybe a mistake was made during installation. Maybe it was mistreated somehow earlier in its life. Bit early to call it "Russian Roulette" I think.

There are real accident investigators looking at the actual evidence right now, if they come to the conclusion that a faulty bolt might have caused this I bet we'll hear about it pretty soon.

[topendtorque]

Hey Lebl,

Would you agree that if you can see any portion of the bolt on the side opposite the nut, without that side of the hub attached that regardless of whether that part of the hub is still attached to the helicopter or not that for the bolt to escape it it means the end must have come off. or the hub split at the bolt hole.

Unless Houdini was up there with a hacksaw unbeknown to anyone.

I agree, we would all like to hear some positive answers and pronto, they have had the bolt and hub now for more than long enough to crank up an electron microscope and peer at it.

Totally unfair to be sitting on that sort of evidence.

[500e]

Bit if thread drift LELE I an others were commenting on Helichoppers bolt on floor & wondering :uhoh: + ATs comment regarding their accident, If it had happened in flight would the mast damage have suggested low G.one blade escaped other flapping.
Bolt stretch V torque both have their place & their draw backs, I still think the bolts from that batch & the manufacturing process\ facility should be checked.

[topendtorque]

A paucity if information still exists on this one, but for Lebl sake i just want to say that an open mind is required that I am not being one eyed about a "failure" because of manufacturing. It may be a failure as a result of a massive over speed - what would break first - Ive no idea.

But let's say the gentleman was overcome with a muscle seizure type of physical dilemma where he pushed down and on with the throttle.

Its quite conceivable, however if that were the case there should be evidence in the M/R attach points, engine and cylinders and especially the tail boom (whirl mode)

Just looking at a head assy yesterday and contemplating something that I haven't before, which is the rotational forces on the hub caused by - full power in one side -- massive drag back the other side on the Hub M/R hinge joints, which are rigid in plane.

Before i only thought of an RRPM over speed in terms of "stretching" the components.

Combine the two forces, a breakage critical point may soon be reached.

[Comewhirlwithme]

Interesting theory, do we know when we might see an official report?
Regardless, it's an horrendous end to a very skilled pilot, my thoughts, prayers and sympathies are with his family.

[Peter-RB]

Reading and looking at the pictures dose two things to me, it reminds me of just how close amagedon came to me, and that I am still here to say I have not flown any Robinsons since a bucket full of Wupass very nearly did me in when some jerk who had Hired a Robinson just before me created any overspeed situation of (told to me later) 110% +, once I had hit 60Knts the R22 became unable to be controlled and would not turn to port only starboard ( over dense population) I was accompanied by a very calm ATC man who cleared eveything around EGNH and kept telling me he was watching, after a giant cirlce that was the tightest I dared to do I got back, by this time I needed two hands to hold the pole, all the time wondering what those tiny little 6/7 and 8 mm dia bolts were doing, I needed all my 220lbs of strength to stop the stick from just going mad so decided to fly in rather than come to the hover, just as I hit 40knts and about 40ft agl the shaking stopped and eveything was serene, I executed a very careful flare and came to rest, totally wiped out by the adrenalin rush and starting to realise I was down with the atc man saying welldone, ......

I parked and walked.......never to sit in any Robinson again.. this thread really has brought a lot back to me, and it still concerns me that the outfit I hired from did nothing.

Sorry for the thread creep.

Peter R-B Lancsahire UK

[Thomas coupling]

Blimey - PB. Kept that quiet. Enough to put my beer down and re-read it again!
Glad you're still in one piece old boy!
What do you fly now then?

[Peter-RB]

Good evening TC,
How nice to see your post,...Nice to see you care, I have some time on more exotics a pal has a Gazelle so a little of that and a Squirrel plus a nice 109, plus a Jet R, I just like flying it seems to create a mind set of its own away from earth bound folk who dont understand the total thrill of all direction movement.

However never again in anything Robo.:=

Peter R-B Lancashire

[Thomas coupling]

Good to see you are still enjoying the experience even after that debacle.
Life must be good - take care.

TC

[nigelh]

Peter RB ...... Now come on ....you are a hunting , shooting countryman with a taste for fine wines . You even almost live in Yorkshire !!!! I really think that people like you and I should be very careful fraternising with the likes of TC :=. I can tell you no good will come of it .....you will wake up one morning and find he's drunk all your '63 Port and cocked his leg on your sofa :eek:
Don't say I didn't warn you . Now enough of this cosy cosy with the other ranks and get your kit ready for the last day of the season !!!,.

[Peter-RB]

Nige
had a final blast with the old Purdy, good to say I had a left and a right, which has set me up as a hero to some, bastard to others, but who cares, Life in Lancashire the Red Rose County is as sweet as ever and TC is now my bessy, but in the past we did cross swords so to speak.

However I must remind you that when we Lancastrians last crossed swords with you Yorkists WE WON..:p

Peter R-B
Lancashire

[nigelh]

You will have to bring the old Purdy to Yorkshire one day .... I'll guarantee you won't get a right and left at one of my 70 yard high birds off the moor edge :ok:
You are welcome to land here anytime passing !! ( I also have cheap fuel ..)
You can even bring your new best friend with you !!!!!

[Dick Sanford]

Peter R-B. what was the result of the investigation?

[BlairS]

Hello Dick,

In your capacity as an accident investigator, have you seen this type of accident before? Speculation in such circumstances is not often helpful, but do you have any views as to the likely cause?

Best wishes

[Matari]

Not sure if this is the same blade or the second blade.

http://i529.photobucket.com/albums/dd332/bulamatari/Ike%2008/R22%20Blades/R22Blade1_zpsdc973f41.jpg

http://i529.photobucket.com/albums/dd332/bulamatari/Ike%2008/R22%20Blades/R22Blade2_zps1a7b8262.jpg

http://i529.photobucket.com/albums/dd332/bulamatari/Ike%2008/R22%20Blades/R22Blade3_zps88877147.jpg

http://i529.photobucket.com/albums/dd332/bulamatari/Ike%2008/R22%20Blades/R22Blade4_zps054e4cb7.jpg

http://i529.photobucket.com/albums/dd332/bulamatari/Ike%2008/R22%20Blades/R22Blade5_zps559e696e.jpg

http://i529.photobucket.com/albums/dd332/bulamatari/Ike%2008/R22%20Blades/R22Blade7_zps888a89c7.jpg

http://i529.photobucket.com/albums/dd332/bulamatari/Ike%2008/R22%20Blades/R22Blade8_zps564e4cbe.jpg

http://i529.photobucket.com/albums/dd332/bulamatari/Ike%2008/R22%20Blades/R22Blade9_zpse68dc215.jpg

http://i529.photobucket.com/albums/dd332/bulamatari/Ike%2008/R22%20Blades/R22Blade10_zps3ae65ab2.jpg

http://i529.photobucket.com/albums/dd332/bulamatari/Ike%2008/R22%20Blades/R22Blade11_zps48c2fef2.jpg

http://i529.photobucket.com/albums/dd332/bulamatari/Ike%2008/R22%20Blades/R22Blade12_zps3c58b77c.jpg

http://i529.photobucket.com/albums/dd332/bulamatari/Ike%2008/R22%20Blades/R22Blade13_zps9e672987.jpg

http://i529.photobucket.com/albums/dd332/bulamatari/Ike%2008/R22%20Blades/R22Blade14_zpsf9ecc7a8.jpg

http://i529.photobucket.com/albums/dd332/bulamatari/Ike%2008/R22%20Blades/R22Blade17_zpsb0b6b18a.jpg

[Dick Sanford]

Hi BlarS. I am not sure what type of accident it is so it is not possible for me to comment, which would not be helpful anyway.
However I have seen this sort of failure of the rotor system before. As with all accidents I advise waiting for the investigators to complete their work.

[topendtorque]

Thanks Matari, something for us to chew on, looks like the same one.

[gulliBell]

Me, being more familiar with the Bell 204/205/212 rotor system, can only iterate my amazement at the frugalness of metal quantity in that R22 rotor head. And of what metal there is, most of it is either torn/ripped/fractured/bent in that sorry looking set of photos in the above post.

Those clever technical boffins in the NTSB metallurgical department with their electron microscopes and xray machines and other fancy gadgets will no doubt quickly sort out what happened and why.

[herman the crab]

That's a lot of growth quickly... how long were they underwater?

HTC

[topendtorque]

We sure hope so. I have a couple of photos somewhere of a set of blades with chord wise ripples clearly seen on the underside at about station - the inboard end of the torn sample.

We never figured it or got back a report but AFAIK the blades were sent somewhere for examination. I'll see if I can find the photos at least. They came off a helicopter R22 with the same blade dash number I think that the late pilot of which had a reputation for being - allow me to suggest - a tad aggressive at times.

As I chew I start with two fresh ideas the close ups has given me.
1. The steep nose down attitude of the helicopter as it was photographed on descent, which with 1 POB should have had C of G reasonably aft of fwd limit,
and,
2. I wonder -- where / if -- there is a nodal point for periodics when these blades approach compressibility?

well dammit there they are first go. see the crease marks underside of blades.
http://i1274.photobucket.com/albums/y421/topendtorque/helicopter%20blades/bth_THPBlade011_zpsdbdb37bf.jpg

[blakmax]

Matari

The separated blade segment intrigues me. I can see several photos which show the adhesive on the front of the core, but there are no shots of the matching surface on the spar. Any chance?

Regards

Blakmax

[gulliBell]

So can we say your hunch is: blade segment fails, resulting in severe in-flight main rotor system imbalance, resulting in failure of main rotor hub, resulting in separation of main rotors?

[blakmax]

gB, I am just trying to look at possibilities. I am not advocating any position yet. The fracture of the skin along the spar line makes me suspicious of one type of failure I have seen on an entirely different (F-111) aircraft, where an ineffective bond between a rudder mast and the core led to fatigue cracking of the skin and subsequent in-flight failure of the rudder.

Now almost every designer does not even consider this failure as possible, because the shear strength of core is an order of magnitude lower than the shear strength of the adhesive, so in many designs, this failure is not even analysed. In cases where the core-to-spar bond is ineffective (or fails) the out of plane shear loads must be carried by only the skins, and given that the R44 stainless steel skins are only about 0.006 inches thick, this failure mode is a possibility.

The photos of the rear of the spar will be of importance because if there is no adhesive on the spar (or minimal amounts of adhesive on the spar) then it is of fundamental importance to carefully check the skin failure using SEM or even just optical microscopy to see if there is any evidence of fatigue in the skin fracture. A further complication is that if they need SEM to find traces of adhesive, then there is another failure mode which can be significant and may lead to a different cause of failure.

If there is a significant amount of adhesive on the spar, then this failure mode is excluded.

If there is minimal or no adhesive and if there is evidence of fatigue in the skins then this approach must be further investigated. Again, I would expect that failure of the blade in this manner would result in blade impact on the fuselage as one blade looses lift, and apart from some indirect observations, I have not seen any evidence of such impact.

Another reason to consider this aspect is that it is unusual to have a segement of blade snapped off like that. If the segment was dislodged by impact, it must be out of plane to cause the skin to fracture at the back of the spar. The bond to the spar is only of the order of 0.5 inches long in the direction of rotation so impact with the water would be expected to cause peel failure of the skin-to-spar bond, rather than fracture of the skin.

These are my thoughts. I am NOT at this stage suggesting that this was the cause of the crash. All I am saying is that a simple investigation would exclude any further consideration of that factor.

Let's see what the photos look like. And in anticipation of the "leave it to the crash investigation experts" responses, I would bet the family jewels on the fact that adhesive bond failures constitute less than 2% of an average investigator's range of experiences, let alone expertise. This has been my bread and butter for forty years.

At 65 years old, the family jewels are not worth much these days.

Regards

Blakmax

[Matari]

Blakmax,

Here is the matching surface on the spar side. Those barnacles do work quickly. One of the treasure divers mentioned that he was down for an hour or so and already had barnacles on his tank.

http://treasureworks.com/images/fbfiles/images/P1000017.jpg

[Peter-RB]

BM,

Isn't the R44 leading edge only Stainless, with the rest being ultra thin rolled Aluminium Alloy covering the honeycomb, with machined end caps?

Peter R-B
Lancashire

[topendtorque]

No the -4's were very thin, 8 thou stainless steel over the honeycomb.

An over zealous and careless tap test is about all it takes to put a limiting dent in them.

Earlier -2 was alli - 25 thou..and now the later dash number I believe to be the same.

Poor old Dick musta got the poos and pinged off, measurements clarified if that is all he is on about as below I don't know.

[Dick Sanford]

It really scares me to see such misinformation on these sort of subjects!

[topendtorque]

It really scares me to see such misinformation on these sort of subjects!

Which devil are you advocating about Dick Old boy? If something is wrong, well hop in and correct it, most of us are easily corrected. That is what the whole forum is about I thought, information flow.

cheers tet

[blakmax]

Thanks Matari but apart from a very small amount of the foaming adhesive which appears to be in an appropriate condition, I can not see sufficient to make any further comment.

Regards

Blakmax

[Morane]

Accident in UK with similar damage.

Air Accidents Investigation: Robinson R22 Beta, G-CHZN (http://www.aaib.gov.uk/publications/bulletins/february_2013/robinson_r22_beta__g_chzn.cfm)

[topendtorque]

Thanks Morane and great to see the report out in the 12 months as predicted.

I will certainly need to read it several times, but so far the Florida case seems dissimalar to all mentioned by virtue of the visible blade damage / failure. Whether that failure occured prior to or after blade separation will need to be ascertained.

The only common denominator being the critical breakage point under extreme load - those pesky coning bolts.

once again Thanks
tet.

[[email protected]]

The pictures of the main blade at the root end with the pitch change arm look very similar to those in the UK accident that Morane links to - definitely worth a read!

In the UK case, the conclusion is that mast bumping leading to hub failure and blade separation was the cause but the reason for the mast bumping seems to be focused on a harsh cyclic input since there is no evidence of a pushover or turbulence.

What is interesting is that one of the blades flapped so much that it hit the left skid! If that wouldn't damage a blade badly, what would?

Ref the pictures of the Florida blade - was the detached section found with the main blade or not? If it was found with it then it is very unlikely that the separation occurred in the air.

Peter - like you I won't ever get in a R22 again - my last experience of one led to a write-off (dynamic rollover).

[susieqfish]

Standing on the shore.....heard a helicopter coming.....looked up and was just to about 1 o'clock position at about 500 feet, approximately 350 yards offshore.

I thought he was a bit low, but was flying level with no deviations, parallel to the coastline. Aircraft was operating as normal, engine sounded normal, was no evidence of any problems.

Looked back to the ground and at that same instant K-BLAM.....very loud metallic separation sound, looked back up and was already inverted and heading straight in.

Aircraft hit the water at a 12 o'clock position from where located on the bank. Did not see the blades splash, as was watching it hit the water. Was pretty shaken up, but watched as a person in a kayak paddled out to the site and recovered some body parts, put them on the bow of the kayak and paddled to position on the bank. Was not a pretty site, lungs and attached esophagus, had enough of that and left the scene.

Returned almost a month to the day after seeing the reward offered on the internet. Using side scan sonar, located blade one quite quickly, about thirty minutes searching from where aircraft was observed going in. Dropped a buoy on the site, 11.5 feet of water, my buddy hopped over, visibility very limited, no more than 1.5 - two feet..... tied a rope and buoy to the blade and recovered it. The blade as in the picture had the chunk broken out of the tip, but the chunk was still just barley attached by a bit of aluminum, and remained that way when turned over to the FAA.

Unfortunately did not have any more air on board and was forced to abort recovering blade two. Returned the next day with adequate air and searched...and searched....found some more anomalies on the bottom at site of blade one, got a grapple hook on them but was unable to lift them, looks like part of the air frame and one of the skids. Did not dive them as was more interested in the other rotor. Took many pictures of the bottom, don't know how I missed seeing blade two on the monitor but I did.

Returned home and downloaded the images. Looks to be part of the skid, and more airframe from what I can tell. Then upon review of the remaining images, there it was...blade two lying all by itself, not far from blade ones position. Close inspection you can clearly see the rotor hub, and complete blade lying on the bottom.

Blade ones hub was still full of oil, although the seal was compromised by the twisting of the metal. I do not believe it was mast bumping, as the aircraft was flying straight and level, with no apparent issues until it went K-BLAM, in an instant and went in.

The chunk that failed out of the blade looked as though it was cut with a scalpel on the spar side, a very clean cut, not something that would have happened on impact I believe. The two sides of the chunk are ragged separations, not perfectly straight and clean as the spar side failure. From a layman's view, looked like the chunk came out of the blade, causing the rotors to be out of balance, shearing them off the mast.

this is blade two....
notice the scale 51 feet.....blade is about 20 feet
http://treasureworks.com/images/fbfiles/images/Capture.JPG

http://http://treasureworks.com/images/fbfiles/images/Capture.JPG

and this is the airframe parts, I believe part of the skid...and cabin...


http://treasureworks.com/images/fbfiles/images/Capture1.PNG



http://http://treasureworks.com/images/fbfiles/images/Capture1.PNG

[Matari]

I was browsing the other threads and I noticed this pic posted by a fellow PPruNer, showing a totally unrelated accident (T/R strike), different aircraft (206L), but with a very similar M/R blade honeycomb separation.

Funny how the failure is just aft of the leading edge, with what appears to be a similar sized chunk of honeycomb missing. Does it mean anything? I don't know, but just interesting in its similarity.

http://www.helicopterservice.com.au/photos/pprune/Wire%20strike%2010a.jpg

[susieqfish]

Rotor was on the bottom almost exactly 30 days when we recovered it...and funny thing is the chunk that was hanging by a small piece of aluminum, was almost totally covered in barnacles, while the rest of the blade was sparsly populated. I think it is because the piece was slightly elevated off the bottom by the buoyancy from the air in the honeycomb. This would allow for better water circulation and faster growth of the barnacles due to increased feeding ability in the water column.

q

[Thomas coupling]

Susiegfish - thanks for your post a very interesting and illuminating description of events. Appreciate your time.

[gulliBell]

You'd think if that segment had come out of the blade in flight the aerodynamic loads would have torn it out completely, so maybe that damage ocurred when the blade hit the water?

By the description given of human body parts the blade has obviously gone through the cabin inflight and hit the pilot....or at least the roof/canopy. Thankful for small mercy the deceased pilot was probably killed instantly without knowing anything, unlike the UK pilot mentioned in the AAIB report who was still alive when the R22 hit the ground inverted after falling from 1500'. Just awful.

I have been contemplating doing my CFI....these in-flight breakups of R helicopters mean I will choose to do it in something not built by R.

[susieqfish]

No problem, not everyday you see something like this....I will get back out and recover the other blade as soon as the weather cooperates!

ENGLEWOOD TO TARPON SPRINGS OUT 20 NM- BONITA BEACH TO ENGLEWOOD OUT 20 NM- 430 PM EST SAT FEB 16 2013 SMALL CRAFT ADVISORY IN EFFECT THROUGH SUNDAY MORNING TONIGHT NORTHWEST WINDS 20 TO 25 KNOTS THEN BECOMING NORTH AROUND 20 KNOTS AFTER MIDNIGHT. SEAS 6 TO 8 FEET. BAY AND INLAND WATERS ROUGH. A SLIGHT CHANCE OF SPRINKLES. SUNDAY NORTH WINDS AROUND 20 KNOTS DIMINISHING TO 10 TO 15 KNOTS IN THE AFTERNOON. SEAS 4 TO 6 FEET. BAY AND INLAND WATERS CHOPPY.

q

[susieqfish]

I am pretty sure the blade did not go through the aircraft...they separated and were thrown clear of the airframe, the pilot suffered massive injuries on impact with the water.....the blades , blade, was in perfect condition, no evidence of collision...we shall see what blade two looks like....from the side scan, appears to be untouched and in same condition as blade one, minus the chunk out of it...

q

[topendtorque]

Susiegfish You deserve the highest praise and thanks for you efforts and astute observations. Has or can someone pick up remaining blade, although it may be academic only.?

regards tet

[Matari]

susieqfish,

Thanks again for posting the pics and description of events. As you can imagine from scanning this thread, many here would be very interested in seeing pics of the second blade, if / when you can recover it.

[[email protected]]

Gullibell - the forces involved in such a crash mean it is very unlikely that a human body will remain in one piece (or even large pieces) - sorry to be gruesome but that's the way it is.

[dmark1]

Robinson widow maker
Rest In Peace my sincere condolences......

Welcome to the Crapinson Flimsicopter no surprises here very sadly a regular & common event.

Happy Landings

VF


What an incredibly insipid statement. Wonder why so many are flying around safely?

I think the Robbie is a great little helicopter, but like anything mechanical it CAN fail.

[SARWannabe]

like anything mechanical it CAN fail.

.... like the engine in Vertical Freedoms bird :E

[Soave_Pilot]

.... like the engine in Vertical Freedoms bird

Touchéé... :}:}

[Vertical Freedom]

But, when I had 2 engine failures; 1 in a B47 20years ago & the other in a AS350 everyone walked away with no injuries. :ooh: machines left up right & intact :uhoh:

Please read this forum; it IS the Robinson that kills the MOST Pilot's of any machine made on this planet :(

Happy landings always :ok:

[gulliBell]

...Please read this forum; it IS the Robinson that kills the MOST Pilot's of any machine made on this planet..

I think I read in an AAIB report that the occurrence/flight hour of in-flight breakups of Robinson helicopters is 3 times higher than any other helicopter...

I vote with my feet and leave the R flying to those brave R fliers, not for me I'm afraid...

[[email protected]]

Dmark1 - I suggest you read the UK AAIB report as it highlights that even very serviceable Robinsons are just a harsh cyclic movement away from an in-flight break up.

[SARWannabe]

VF - I know, I know. Just playing with you :ok:

[topendtorque]

VF
VF - I know, I know. Just playing with youBut I am not, it's most tiresome I am pretty much right over your continual cynicism. If you wish to be critical for god's sake quantify it. It is well known that AS 350's have been biting the dust and killing people with regular monotony of late. This could be assumed as not of pilot error mostly as they are crewed by either professional or high time pilots. By contrast R22's by and large are exposed to ab initio pilots of the highest number of any type.
Many of their other statistics have been because of overload, over flying of hours and also because of many of my brethren (Pilots who have got into flying them mustering without any degree of respect, knowledge or finesse of flight control and general aviation machine tolerances, I.E. they aint a pilots backside mate) who take liberties with the controls any flying machines is clearly not designed for.
VF you would know that from your background in OZ. If you don't then you are exceedingly unobservant. I suggest your attitude is not making it easier at all for those who have to fly these machines day in day out, so Pull your bloody head in please and do some research. Your two incidents don't come within a bull's roar of comparing with 39 times onto the ground without scratching any of those of which only three were in R22's of mine, if you want some real experience come see me.

Crab.

are just a harsh cyclic movement away from an in-flight break up. I hear what you are saying but as per the above, these gadgets have probably amassed well more than 3 million flight hours under the mustering regime. It would be absolutely extraordinary for the, shall I say those with less finesse to have not proven that conclusively by now. However having said that if one were to say, be flying along without the cyclic bias (lateral trim) not engaged and let the cyclic go then maybe it is possible to do just that. The untrimmed cyclic will sure flick quickly if let go.

As in both cases recently highlighted, it would be very hard to imagine an experienced F/W pilot to fly along in an untrimmed state once established in cruise, say they then get a fright with the indication of the Carby air temp - let go the wheel - and be in that predicament.

Despite the numerous attempts by my brethren and others to over control to the point of break up - perhaps it is possible. I would be interested to hear what the house of Robinson did with the test flying regimes in that area.
But, as we all know it is certainly not a good idea to be too preconceived with ideas about any matters in aviation I think you will agree.
I have no problems admitting to over controlling to the point of machine shudder in the past, but I don't jerk controls unlike one of my colleagues who came home one day with a mast on a '47 broken one third the way around under the clamps of the no bar kit.. So you could well be right.

all the best tet

[Ag-Rotor]

The upper end of the Rotary Pilot world seem to constantly slag off at the Robinson brand of Helicopters as being some inferior product best left to the lower class of Sky Dwellers. Well while they all spend more time with their dicks in their hand than a cyclic....Robinson helicopters are out there in masses going to work or play every day and bringing their pilot home safely each and every day?

[Vertical Freedom]

Good morning topendtorque

Opinions are like a...*oles everyone has one! Some people like Holden's others Ford - so what, it's just an opinion & not fighting words. :hmm: This Forum is an open Forum; non racist & non discriminatory hence we are all free to give opinions. :ok:

My opinion of the Crapinson is that only - 'an opinion' & as we don't yet live in a Police state, I am free to think & voice those opinions, as we all are. Sadly those opinions are based on 23 years in this game having had friends killed & nearly killed from blade delaminations & other in-flight break ups. Not caused from inexperienced Pilot's but from under built sub standard machines. I have a number of Engineering Friends that hate them with a passion & do not trust them, from their perspective. I have seen a a Robo blade with signs of delamination brand new, still in the box :mad:

Maybe Your offended by my words, maybe it's because deep down You also know some of these things to be true :{

You are right; all machines have some draw backs, some limitations. But not to the extreme, obscene extent as with Robo's. I don't buy the argument that it's mostly caused by a lack of skills, that may be true in the odd case but not the majority. :yuk: Just like on this thread the Pilot who died in Florida from an in-flight break up, he was a highly experienced Fixed & Rotory Pilot/Instructor??? Yes, I have had an engine failure twice, in a Bell & a Aerospatiale product, & yes all my PAX & I walked away without a scratch, no post crash fire, all safe & well. :ooh:

39 engine failures followed by successful landings, oh my God, that has to go into the Guinness book of records, that is frightening. You truly are Blessed by the God's to be still gracing the Earth with Your presence, well done :ok:

As for helping, not help Pilot's in Oz????? I think the more information spread out there will help people be more informed about their choice of training machine etc. If the majority of students/Pilot's boycott this machine, then more growth would be seen in more worthy machines, or maybe the Robo factory would sharpen their pencils :suspect:

I am humbled by Your offer to give me some real training experience...I'm always keen to learn something new & look forward to developing new skills that would make me safer & more efficient, thank You :)

Om Shanti Shanti Shanti (Aum Peace Peace Peace) :cool:

Happy Landings :D

VF

[Brian Abraham]

Your two incidents don't come within a bull's roar of comparing with 39 times onto the ground without scratching any of those of which only three were in R22's of mine, if you want some real experience come see me.39? That's so absolutely incredible as to be unbelievable. Would love to see a listing of the causes of all 39. Lousy maintenance?

[gulliBell]

But Brian, you got shot down about that many times in the war, particularly on a Sunday. I find that absolutely incredible :ok:

[Thomas coupling]

The R22 issue has been beaten to death on this forum. Lee Zuckerman (RIP) did much to bring the inadequacies of the R22 to everyone's attention causing mayhem amongst contributors:eek:

http://www.pprune.org/rotorheads/20616-certification-robinson-helicopters-incl-post-frank-robinson.html

Topend Tq: I think you'll find that at your end of the globe, especially in the mustering world, it has been a red rag to a bull when mentioning R22 safety. That industry has done nothing to uphold the virtues of the toy helicopter - unfortunately. And you have to accept that you are unique individual anyway - it seems no matter what helicopters throw at you - you escape unscathed :D
However, for the rest of the world, these damning statistics are still trickling through. The problem without a shadow of doubt is that Frank built a fragile sensitive CHEAP helicopter available to the masses. Flying schools bought them in their dozens and taught wannabees how 'easy' and affordable it was to fly them.

It was the coming together of an unforgiving and fragile helicopter with very very low time inexperienced pilots that cases all the problems.
[There are exceptions like the latest stoof in the US].

I think the tide is turning slowly and more and more pilots are, shall we say...shying away from them and sticking with sturdier more forgiving die hards like the Schweizer..et al.
I might even see an R22 free world in my time.:eek::suspect::ouch:

[nigelh]

YIPEEE:) TC and i agree on something :ok:
I was tasked to take up a student way back in 1980 ( approx ) in one of these new fangled Robbos . I was only about 21 and had a couple of hundred hrs . To cut a long story short ....the student and i got back on the ground within 20 mins , got out and went and had a beer and a fag ( cigarette in US .....) . It was the most afraid i have ever been in a helicopter , incl the time a blade came through the cockpit !!!! I wrote a report to say that for an experienced pilot it may be fine but for someone of my ability and hrs it was a deathtrap:ugh:
and it was totally unsuitable for low hr pilots and training .
That was my view then and i havent changed it in over 30 yrs .
I would train on a 300 or if you have to a 44 but NOT a 22.

[Thomas coupling]

Couldn't have scared you that much NigeH, you don't have any grey hairs on your bonce;)

[bhawkh60]

Pardon my ignorance, but as an A&P with 18 years working on Sikorsky and some Bell stuff I've never heard of "stretching" a bolt. How exactly does that work?

[FSXPilot]

Instead of using a torque wrench you measure the bolt before you tighten the nut and then measure the length of it afterwards until you reach the required stretch figure. There is a jig that fits over the area that allows you to do this.

[Thomas coupling]

You're joking right?
I rebuild cars and come across steel bolts that have stretched. Every time a wrought iron or steel panel or bolt bends it stretches. I can easily imagine a MRH bolt stretching after 1000's of hours of centripetal force.

http://www.tracystruesoaps.com/tutorials/850hg/stretched_bolt.jpg

:confused:

[FSXPilot]

Go look at the AMM if you don't believe me, It's on Robinson's website. I happen to think the R22 is a deathtrap.

[bhawkh60]

TC

I wasn't saying I don't get the idea of a bolt having some give, but I've sure as hell never seen it as a procedure.:sad: Having spent most of my life in Sikorsky Hawks and 92's I'm not used to seeing sraight steel hdwr anyway. Most all of our stuff is Cad or Titanium. Think I'll stick with the 10,000 lbs+ class helicopters.

[FSXPilot]

Also you have to realise that every time you tighten a bolt you are stretching it. That is how it becomes tight. It's not stretched beyond it's elastic limit.

[FSXPilot]

I'll take a photo of an new R44 blade bolt tomorrow. The bolts are Cd plated steel alloy.

[500e]

TOOL REVIEW: TORQUE PLUS ANGLE IN ONE TOOL Precision Engine (http://www.precisionenginetech.com/tech-explained/2011/05/20/tool-review-torque-plus-angle-in-one-tool/)

Hope this helps bh60

[topendtorque]

Would love to see a listing of the causes of all 39. Lousy maintenance? will do soon as I can get back, bit busy at mo.

my brother used to be in the fastening of bolts, big bolts using hrydanuts. I'll see if I can dig a couple of old photos one day soon. Installed many in most of the hot ends on nuclear powerhouses right round the world. One amusing story about how when trying to describe to his kids why he couldn't be called on cell phone one day, "these joints are designed so no radio waves get out, so nothing sure as hell can get in."

Those bolts sure seem to be this issue. Yesterday peddling around chasing bulls, big storm blew up lot of gusts, just absolutely nothing to give one the feeling that there was any shock loading to be had out of it. Seems to me there has got to be a shock loading on one side that must happen to cause the knee to break in the middle and understandable that each of the two joints being the weakest links or section would break simultaneously.

Thanks TC, yes I only read some of the late gentleman Zu's posts, but in reality I think if VF's friends are so damn clever they should all head over to FAA land and take over the certification processes and examinations processes of A&P people.

Despite all criticisms these gadgets have been approved by sound and well tested basic engineering and flight testing principles.

VF does an excellent job where he is all credit to him, but he can step away from common slander I think quite easy - all a bit different from personal preferences which are easy to respect. Slander earns the biffo response and I make no apologies in that respect

If we were all to get grounded tomorrow it should not be surprising, after all that sort of thing has happened before despite intense engineering effort, have a look at the B787 for example, the M/R grips on the B47's another.

cheers tet..

[ShyTorque]

http://www.tracystruesoaps.com/tutorials/850hg/stretched_bolt.jpg

Not only has the bolt got longer, the head has changed shape, too!

[oleary]

bhawkh60 wrote:

Pardon my ignorance, but as an A&P with 18 years working on Sikorsky and some Bell stuff I've never heard of "stretching" a bolt. How exactly does that work?

... and, ...

I wasn't saying I don't get the idea of a bolt having some give, but I've sure as hell never seen it as a procedure.http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/puppy_dog_eyes.gif Having spent most of my life in Sikorsky Hawks and 92's I'm not used to seeing sraight steel hdwr anyway. Most all of our stuff is Cad or Titanium. Think I'll stick with the 10,000 lbs+ class helicopters.

-------------------------------------

Yikes, I sure hope you are not licenced to actually sign off on anything :=

[[email protected]]

I think obsessing about the bolts is a red herring - even if they were made of titanium they would break because the design of the rotor head allows such high stresses to be placed on them.

If you haven't already read the latest UK AAIB report on the R22 fatal referred to earlier, it highlights that the extreme flapping that can be achieved by the R22 head creates an off-angle pull on the pitch change arm which can either tear the top end of the arm from the head or stress the bolt so much that it fails.

The 'clever' (and cheap) design of a teetering hinge flanked by two flapping or coning hinges allows too much flapping resulting in mast-bumping and mechanical stress on the head.

[Peter3127]

I was helping a LAME rebuild a Schweizer rotorhead passing tools etc. (incidentally a great way to learn how they work) and I can vouch for the fact that the procedure called for the blade bolts to be measured, and then torqued until they had stretched "X" thousand of an inch, where X is a number I cannot recall exactly but think was 9 thou, or about 0.23 mm. :ok:

[Thomas coupling]

For the benefit of SHY: the picture is not of the same bolt. The 'NEW' bolt is a new bolt. The 'OLD' bolt is another bolt but older. Because the bolts are not mandated to be identical or same batch, the bolt heads can be different, so too the collar. As long as the thread is the same in terms of diameter and length, that is all that matters. Sometimes, Shy, the bolts are different colours too:D But this example (because it is just an example) shows them to be the same colour for simplicity (and because I didn't have different coloured bolts).

However, you missed a trick: I could have raised the old bolt a little higher and that would have shown the phenomena to be even more prevalent. But that would be cheating and people like you would have commented.

Would you like me to show you the other end of the bolts?

:rolleyes:

[Dick Sanford]

Nigelh. In 1980 the R22 was Certified in the Private Cat. Therefore your student must of been an owner. There was only one company training at that time and the training was for the owner on the owners helicopter. I might be mistaken but I knew all the customers (not many at that time) and do not remember such a situation.

[fly911]

Oleary: Yikes, I sure hope you are not licenced to actually sign off on anything.

Not a very admirable thing to say. Have you been bullying very long?

[nigelh]

Dont you worry ...were all bullys here :D
Dick ....I may be a year out and it could have been 81. It came to Simpson Helicopters in Houston to be evaluated as a trainer . Very low inertia blades ....0.1 sec to get lever down ....scary :eek:

[bhawkh60]

oleary

You've got to be kidding me. You can read Sikorsky tech pubs or FAA hardware study guides all day long and will never find reference one to "stretching" a bolt. It's all TQ values.

As far as "Yikes, I sure hope you are not licenced to actually sign off on anything := ":

What part of A&P confused you?

[brett s]

I understand the concept behind measuring bolt stretch to determine preload (and why it's better than using torque in some applications), but I've also never seen it called for on the particular helicopter & airplane types I've maintained in the past.

So, no, I wouldn't consider it to be unusual for an A&P to never have done it - I fall into that category myself.

[Brian Abraham]

I've never heard of "stretching" a boltMeasuring bolt stretch is actually the most precise way of pre loading a bolt. Of course the method has its limitations in that you need access to both sides of the bolt to be able to measure with the tool/gauge (micrometer). Robinson apparently teach the procedure in their factory maintenance school.

Maintenance Training The Robinson Way - AviationPros.com (http://www.aviationpros.com/article/10841312/maintenance-training-the-robinson-way)

[cockney steve]

"Stretch- bolts" have been common in the UK motor-trade for~20 years!

When the first engines appeared with them, we assumed it was a racket to sell more parts :O

Up until their introduction, it had been normal to torque in stages and sometimes time-lapses between stages.....sometimes run to working -temp amd retorque hot, others cool and retorque .still others nail them down and send 'em out.
then came stretch bolts.... low initial torque , then mark all heads with a paint-stripe, then wind each one so many degrees in diffferent stages.....you'd feel them "twang!"..It needed a bit of research , (easy, nowadays with the internet.) A much more accurate way to tighten, as it virtually eliminates the problems caused by burred/damaged/dirty threads.

[bhawkh60]

That is some intersting stuff. I'd doubt I'll see it on any of Sikorsky's stuff anytime soon since most all of our flight critical hardware is inaccessible and uses externally installed bolts threaded into inserts or barrel nuts, but I manage GSE across the H-60/ S-70i fleet so I always have my eyes open for new stuff.

[Chopper Doc]

What you're describing Steve is very different. On the head of a Robinson you can get to both ends of the bolt and measure the bolt before it is tightened and afterwards. The correct tool just fits over the bolt and allows you to use a dial gauge DTi to measure the increase in thousands of an inch.

[oleary]

bhawkh60 wrote:

You've got to be kidding me. You can read Sikorsky tech pubs or FAA hardware study guides all day long and will never find reference one to "stretching" a bolt. It's all TQ values.

As far as "Yikes, I sure hope you are not licenced to actually sign off on anything := ":

What part of A&P confused you?
__________________________________________

Two points:

(1) But that's all TQ IS! You are simply stretching a bolt to a prescribed a value! And on really critical applications it is taken one step further to include special grease and a rotational limit in which you must get the prescribed TQ.

(2) Re your A&P - my point exactly. Where did you get it - out of a popcorn box?

[500e]

Here is a cheap one, cockney s more like 40 years Peaugot among the first
http://ecx.images-amazon.com/images/I/41%2BCxSrV0LL._SL500_AA300_.jpg

[Matari]

oleary,

You've hijacked the thread. bhawkh60 simply said that on the aircraft he has worked on, he has not applied the specific procedure of measuring bolt stretch as a function of measuring proper torque. Nor had I, after years as an AMT.

Had he been assigned to work on a Robinson, he would have seen the written procedure, and followed it in accordance with the manufacturer's specifications. That's what a good A&P does. Get off the tiny soapbox, please.

[Efirmovich]

Just as an aside,,,,,There was no torque figure for any pre-war Rolls Royce engines. RR mechanics were trained to "know" how tight and "feel the bolts down".... proper engineers, how times have changed... :ok:

Don't worry I'le get me coat......... !

E.

[Matari]

As said earlier, bolt stretch is a simple concept, easily understood and applied.

However, these are not tractors. These are aircraft. If the procedure is not called for in the OEM maintenance manual, then you do not perform the procedure. If it is, then the AMT performs the procedure. In many cases, an AMT can work on a variety of aircraft in his/her career where bolt stretch is not an approved procedure according to the OEM. That is the point you seem to be missing.

'Nuf said.

edited for Efirmovich: Don't forget the old German torque applied to the Bolkows..."Gutentite"

[Brian Abraham]

There was no torque figure for any pre-war Rolls Royce enginesRecall a story written by a chap who as a youth on an apprenticeship was given the task of tightening bolts in the construction of spars for Spitfire wings. Kept snapping the bolts. In those days the length of the spanner was stipulated, and in that way the average man wouldn't over TQ.

[Deaf]

Seen it done that way with vibrofeeders - 3,000 ftlb so fitters on the scales and some calculations.

[Arnie Madsen]

Overtorquing bolts also distorts and stretches the threads ..... whether in automotive , industrial , or aviation.

Do a little test on your next coffee break in the shop ..... and do it in front of all the musclemen who figure tight as hell is good enough.

Use common grade hardware store bolt , 3/8" by 2" long. ...... place a nice stack of washers on the bolt until there are only enough threads showing for the nut to be installed ...... use two wrenches and tighten normally ..... then as hard as you can .... tighten it a lot more.

Spin the nut off , remove the washers , and try to spin the nut all the way down the threaded area .... you will only get partway because the threads have been stretched and the nut will bind. You should even be able to visually see where the threaded area has stretched.

Next time you are having trouble changing the tire on your car because the wheel nuts are hard to turn ..... some muscleman at some gas station has stretched the wheel studs with a 250# impact wrench.

[Saint Jack]

If I remember correctly - and I often don't - the installation of the power turbine rotor in the LTS101 engine requires a combination of torque on the retainining nut (applied with a torque wrench) and stretch of the shaft (measured with a DTI). Both must be within prescribed limits to achieve an acceptable installation.

[topendtorque]

If I remember correctly - and I often don't

And, the Jesus nut on the '47 with a 24" shifter, was two and a half white knuckles and a reasonable resonance. Yarpis might refer to that as a - ffwawt

[68fish]

I also work hardens the bolt.
Robinson helicopter rotor head hardware is stretched, not torqued.
Not only that, the nut head is drilled and cotter pinned after the proper stretch is achieved. Since the bolt work hardens it can only be stretched 2 or 3 times before the drilled holes will no longer match up on the nut.
Then you have to use new hardware.
Bolt stretching is nothing new, the main crank assembly on radial engines required stretch back in the day. :ok:

[topendtorque]

Has the second blade been recovered yet

cheers tet

[susieqfish]

Not yet, water is still cold and I have been busy with other issues....but soon as it warms up a bit more I will go get it.

[fdr]

If a coning bolt has failed to maintain tension due to fatigue/embrittlement/over-torquing, or for any other reason, then the immediate outcome is that the disk is not teetering about the teeter hinge, it becomes some point offset in the direction of the coning bolt that has lost tension. That is annoying in the hover.. in forward flight it would impose some pretty dramatic loads.

[topendtorque]

in forward flight it would impose some pretty dramatic loads. fdr.
To explore; perhaps a major vibration with nodular points along the blades until it whips badly enough to cause the opposite blade to fail and begin tearing - the one with the good bolt - that causes a sudden rotational shock load - which causes its coning bolt and the first failing coning bolt to fail simultaneously?

The damaged blade stays in one piece because at the time of failure it still had not lost the torn piece and immediately had a different flight vector towards the blade tip thus allowing the torn bit which was attached at outer end - to stay still attached.
tet.

[Arnie Madsen]

If a coning bolt has failed to maintain tension due to fatigue/embrittlement/over-torquing, or for any other reason, then the immediate outcome is that the disk is not teetering about the teeter hinge, it becomes some point offset in the direction of the coning bolt that has lost tension. That is annoying in the hover.. in forward flight it would impose some pretty dramatic loads. I think you nailed it .... CF plus the right tension on the coning hinge (frictional pre-load) helps keeps each blade in place so that any flap movement is at the teeter hinge only .... and everything works perfect.

But if one cone hinge has more (or less) freedom of movement than the other .... all of a sudden you have two or three hinge points trying to figure out which one should provide the momentary flap in some situations.

CF should be the main contender in keeping the cone angles the same on both blades ..... but a split second out-of-phase situation could occur if one cone hinge is sticky or one is too loose .... without a drag hinge an out-of-phase blade will begin to self destruct within two rotations.

[susieqfish]

$3,000 reward offered in recovery of missing helicopter blade | wtsp.com (http://www.wtsp.com/news/local/article/327119/8/3000-reward-offered-in-recovery-of-missing-helicopter-blade)

water is warm....time to go!

[blakmax]

Susiegfish

I can tell you from personal experience that much of the meaningful crash information would be well and truly obscured by now. I have seen one of these blades which exhibited evidence of widespread disbonding in the honeycomb section of the blade well away from the edges of the bonds after about one month's submersion and the OEM's response was that the immersion in the water caused the disbonds. Now as an expert in adhesive bond failure forensics I can tell you that disbonds due to water exposure occur from the edges of the bond and propagate inwards. They do not initiate in the middle of a bond.

I'll bet they give the same response this time.

Regards

Blakmax

[HeliHenri]

.
Hello blakmax,
Susiegfish has recovered the first one. :ok:
He's going to try to recover the second one.
too late or not, that's doesn't concern him.
Robinson or NTSB will say if it was worth it.
but I think you're right.
.

[susieqfish]

This is a view of the second blade, you can clearly see the shaft side of the rotor, and appears to be in one piece unlike blade on that had a chunk out of it, but was still hanging on by a thread...I am going to get it this week as the water has been unusually clear in Tampa Bay.


blade 2 is in post# 98...

q

[Kiwi500]

I'm surprised this has gone quiet. Can anyone update on this....one of the most concerning seemingly unexplained failures for anyone ever needing to drive a 22, including myself. I might have missed it, apologies if I have.

[susieqfish]

Well.....I tried..again....spent 5 hours on the water with the side scan sonar....expanded my search area for the blade...no joy.....I did find some of the cabin and a skid......but the blade eluded me. It may be in too small pieces for me to discern, or it was flung more then 1000 feet from the original blade site.....

The water is getting cold again, and I am done looking this year.:ugh:

[9Aplus]

For sure all here really appreciate your efforts.
While looking again on your post #98
http://www.pprune.org/7698544-post98.html
blade was there...
Most of us with some underwater experience know well that bottom
of the sea is living beast. Sea can spit out that blade next year, or even
after some more time. Take another attempt while passing by next year,
your luck may be there (like mine, more than once).
The other way now, or after future miss with side-scan, is to go with
parametric sub bottom profiler, but that toy cost bit more than side-scan,
and cover of area is much slower.

[Kiwi500]

Your efforts are definitely appreciated. I'm still staggered that official efforts weren't made at the time to recover all the debris which is surely critical evidence. Were the company/investigators that satisfied that they have covered all the bases regarding cause, so early in the piece, that they were happy to leave the rest behind? I sincerely hope they have it right and we get some answers.:suspect:

[blakmax]

Thanks for reminding us of the sonar images 9A+. Looking at the first image it appears that there is a complete blade and the second shows what appear to be several separate segments of the blade arranged in a neat pattern with some segments missing. Critically the missing segments are from the middle of the blade, not the ends. If this had been a blade failure as for DQ-IHE the blade segments would not be co-located as shown in the second sonar scan.The segments would have been thrown well apart.

I suspect that the failure is not related to the blade itself but may be within the root/hub region. In which case even if the blade segments were found they would exhibit consequential evidence, not causal.

However, I agree with Kiwi500 that there should have been a bit more official effort than just offering a paltry reward that would barely cover the costs for S-q-fish.

Regards

Blakmax

[susieqfish]

The area where I found blade one is only ten feet deep with a smooth hard sand bottom. The ocean is very dynamic, but that is not the case for this area of Tampa bay as it is only a couple hundred yards from shore and in an area where there is no wave/wind activity. The pieces of the cabin and the skid are exactly where they were when I found them last year.

There was much activity after the first blade was recovered, literally dozens of boats out there looking and dragging the bottom for days, so the blade may have been snagged and dragged away by somebody, but that seems unlikely.
I went to the exact area of blade two, and searched extensively but found nothing but the wreck debris previously mentioned.

A sub bottom profiler would not be of much help here, as the bottom is hard sand and I am sure the blade is on top....somewhere. As an example, not far from this crash site there is a huge 6000# anchor and about 1000 feet of monster chain on the bottom that was lost there by a phosphate cargo ship, also in 12 feet of water and the anchor and chain are still right on the surface as if they were lost yesterday, not 20 years ago. So the dynamics of the area there are few and would not cause something to sink, especially a carbon blade being as lite as it is.

So it is a mystery.....if I get bored enough I may give it one more shot as it has to be somewhere......as I hate to loose:{ LOL......

[susieqfish]

NTSB Identification: ERA13FA070
14 CFR Part 91: General Aviation
Accident occurred Friday, November 30, 2012 in Apollo Beach, FL
Probable Cause Approval Date: 02/04/2014
Aircraft: ROBINSON HELICOPTER R22 BETA II, registration: N2626N
Injuries: 1 Fatal.
NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.The helicopter was in cruise flight about 500 feet above ground level, over a bay beach, when both of its main rotor blades separated. The helicopter subsequently descended into the bay, and the wreckage with the exception of the main rotor blades was recovered 2 days later. One main rotor blade was subsequently recovered about 1 month later, and the other main rotor blade was not recovered. With the exception of the separation of the main rotor blades, examination of the airframe and engine did not reveal any evidence of preimpact mechanical malfunctions or anomalies. Metallurgical examination of the rotor hub and the recovered main rotor blade revealed features consistent with overstress, and no preexisting cracking or fatigue was noted. Additionally, damage to the teetering stops on the rotor hub was consistent with mast bumping. The observed mast bumping could have resulted from large, abrupt flight control inputs or from a mechanical failure of the unrecovered main rotor blade.


Toxicological testing and review of the pilot's medical records revealed a history of near nightly use of zolpidem (Ambien) as a sleep aid and frequent use of rizatripan (Maxalt) to treat migraine headaches. Neither condition or its respective prescription medication for treatment was reported to the Federal Aviation Administration and if it had been, would have most likely disqualified the pilot for a medical certificate based on the frequency of use/symptoms; however, the investigation could not determine the effects, if any, that the recurrent migraine, chronic zolpidem use, and underlying sleep problems might have had on the pilot at the time of the accident.
The National Transportation Safety Board determines the probable cause(s) of this accident to be:
Mast bumping for reasons that could not be determined because one main rotor blade was not recovered.


ERA13FA070HISTORY OF FLIGHT

On November 30, 2012, about 1512 eastern standard time, a Robinson R22 BETA II, N2626N, operated by Fly N Choppers, was substantially damaged when it impacted water, following a main rotor blade separation in flight near Apollo Beach, Florida. The airline transport pilot was fatally injured. The personal flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the local flight that departed Peter O Knight Airport (TPF), Tampa, Florida, about 1502.

According to radar data provided by the Federal Aviation Administration (FAA), the helicopter departed its home base at Clearwater Airpark (CLW), Clearwater, Florida, about 1405. It flew over the local area and landed briefly at TPF, before performing another local flight. Witnesses reported that the helicopter was flying along the beach, from north to south, about 500 feet above ground level. The witnesses heard a bang, followed by a main rotor blade separation. The helicopter then immediately rolled right and descended nose down in to a bay, about 200 yards from shore. The last radar target was recorded at 1511:51, indicating an altitude of 200 feet, about 400 yards from shore. Review of the previous five radar targets revealed that the helicopter had climbed from approximately 500 feet, to 800 feet, before descending into the water.

PILOT INFORMATION

The pilot, age 60, held an airline transport pilot certificate with ratings for airplane single-engine land, airplane single-engine sea, airplane multiengine land, airplane multiengine sea, and rotorcraft helicopter. His most recent FAA first-class medical certificate was issued on September 26, 2012. At that time, he reported a total flight experience of 31,500 hours. Review of the pilot's logbook revealed that he had accumulated about 290 hours of helicopter experience; of which, 10 hours were flown during the 90-day period preceding the accident. All 10 hours were flown in the accident helicopter.

AIRCRAFT INFORMATION

The two-seat helicopter, serial number 3644, was manufactured in 2004. It was equipped with a Lycoming O-360, 180-horsepower engine. The helicopter's most recent 100-hour inspection was completed on November 12, 2012. At that time, the helicopter had accumulated 3412.8 hours of operation. The helicopter had flown approximately 55.2 hours from the time of the last inspection, until the accident flight.

A mechanic reported that during the most recent inspection, he had found one main rotor blade exhibiting delamination. He then replaced both main rotor blades with used blades; however, the used blades had 142.4 hours remaining on their 2,200-hour life limit and were inspected before being installed on the accident helicopter.

METEOROLOGICAL INFORMATION

MacDill Air Force Base (MCF), Tampa, Florida, was located about 8 miles northwest of the accident site. The recorded weather at MCF, at 1455, was: wind 070 degrees at 8 knots; visibility 10 miles; few clouds at 8,000 feet; temperature 26 degrees C; dew point 13 degrees C; altimeter 30.17 inches Hg.

WRECKAGE INFORMATION

The helicopter was recovered from the bay 2 days later. The engine and rotor mast remained attached to the airframe. The rotor hub remained attached to the rotor mast and the elastic teeter stops exhibited impact damage. Both spindle assemblies and their respective rotor blades had separated from the hub; one main rotor blade (with spindle assembly) was recovered from the water about 1 month after the accident and the other main rotor blade was not located. The tailboom separated about 6 feet from the transmission and the tailrotor remained with the tailboom. Both tailrotor blades exhibited impact damage. The horizontal stabilizer separated from the tailboom and the vertical stabilizer remained attached to the horizontal. The tailboom exhibited impact damage on the upper left side. The right skid remained attached and the left skid separated. The toe from the left skid was separated and not recovered.

The cockpit was crushed and the windscreen was not recovered. Localized impact damage was observed on the left lower side of the cockpit. Both collectives and the cyclic T-bar remained attached. The antitorque pedals on both sides of the cockpit remained attached. Continuity was established from the tailrotor through the tailrotor drive shaft, to the break in the tailboom, and in to the transmission. Continuity was also confirmed from the main rotor, through the transmission, to the tailrotor drive shaft. The cyclic remained connected via push-pull tubes to the mixer, where push-pull tubes were separated about 1 inch vertically of the mixer consistent with overstress. The push-pull tubes then continued to the swashplate. The antitorque pedals remained connected to push-pull tubes to the lower bellcrank. A push-pull tube had separated about 18 inches vertically of the lower bellcrank, consistent with overstress. Beyond the separation, the upper bellcrank was fractured and there was also a separation of a push-pull tube in the tailboom.

The carburetor heat was in the off position. The mixture control was in the full rich position. The magnetos were selected to both. The fuel selector was not recovered.

The valve covers and top spark plugs were removed from the engine and oil was noted throughout the engine. The spark plug electrodes were intact and light gray in color. The caps were also removed from the magnetos. The crankshaft was rotated by hand via the fan wheel. Camshaft, crankshaft, and valve train continuity was confirmed to the rear accessory section and thumb compression was attained on all cylinders. Both magneto gears rotated when the crankshaft rotated. The carburetor remained attached to the engine and was undamaged.

The rotor hub and the recovered main rotor blade with spindle assembly were forwarded to the NTSB Materials Laboratory, Washington, D.C., for further examination. Metallurgical examination of the components revealed features consistent with overstress and no preexisting cracking or fatigue was noted. Additionally, damage to the teetering stops was consistent with a mast bump (for more information, see Materials Laboratory Factual Reports in the NTSB Public Docket.)

MEDICAL AND PATHOLOGICAL INFORMATION

An Autopsy was performed on the pilot on December 2, 2012, by the State of Florida District 13 Medical Examiner's Office, Tampa, Florida. The cause of death was noted as due to blunt impact to the head and torso. Toxicological testing was performed on the pilot by the FAA Bioaeronautical Science Research Laboratory, Oklahoma City, Oklahoma. Review of the toxicological report revealed:

"Rizatriptan detected in Urine
Zolpidem detected in Liver
Zolpidem detected in Urine"

Review of the pilot's applications for FAA medical certificates revealed that he was first medically certified in 1973 and routinely medically recertified thereafter. The pilot did not report any medications, medical conditions, or physician visits until 2010, when he reported having had hernia surgery.

For many years, the pilot's aviation medical examiner was his personal physician. This physician had prescribed zolpidem (a sleep aid marketed under the trade name Ambien) for many years with the caution "do not fly an aircraft for 24 hours after taking this med." According to pharmacy records, during the last few months before the accident, the pilot had refilled this prescription monthly for 30 tablets each time. In addition, the physician had referred the pilot to a neurologist for evaluation and treatment of migraine headaches and was aware that the pilot had been prescribed rizatriptan (a vasoactive medication used to treat migraines, marketed under the trade name Maxalt) for these headaches. According to pharmacy records, the pilot routinely refilled his prescription for 9 tablets/month. According to the treating neurologist, the migraines were successfully aborted by this medication.

ADDITIONAL INFORMATION

According to the FAA-H-8083-21A, Helicopter Flying Handbook, "…mast bumping is the result of excessive rotor flapping. Each rotor system design has a maximum flapping angle. If flapping exceeds the design value, the static stop will contact the mast. It is the violent contact between the static stop and the mast during flight that causes mast damage or separation."




ERA13FA070 (http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20121130X74908)


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