St Mary's Careflight Bell 412 Crashes Today

[Pac Rotors]

Latest info is that the Bell 412 operated by PHI for St Marys Careflight in Grand Junction, CO crashed this morning killing the pilot.

It was apparently on a maintenance test flight and crashed on the airport. Must have been something major if it didnt even make it off the airport grounds.

[Lama Bear]

More info

http://www.denverpost.com/news/news0301a.htm

[rotorhead4]

Another link.
www.gjsentinel.com (http://www.gjsentinel.com)

[This message has been edited by rotorhead4 (edited 02 March 2001).]

[This message has been edited by rotorhead4 (edited 02 March 2001).]

[Pac Rotors]

Latest I heard this morning is according to witnesses they saw pieces fly off the rotorhead before the helicopter crashed.

Now this makes me wonder what sort of major mechanical failure would have caused this. Any 412 operators out there have any thoughts.

[Lu Zuckerman]

To: Pac Rotors

The following is an excerpt from a newspaper article taken from one of the websites listed in the St. Mary’s’ thread. It describes an accident on another Bell 412. Please note the last comment in the article relative to a disconnected drive shaft.

“One of those accidents happened on a helicopter flight between Grand Junction and Monticello, Utah. A Bell 412 owned by Air Methods Corp. crashed July 1, 1991, according to the safety board's records. Three crewmembers suffered minor injuries. The safety board's report stated the probable cause of the accident was pilot error, inadequate inspection by company maintenance personnel and a disconnected transmission drive shaft”.

The disconnection of the drive shafts on Bell 212 and the 412 is quite common. The US Air Force and the US Navy had a large number of similar occurrences. They worked on the problem for quite some time but I do not know if they came up with a cause. From the description of the eyewitness, he indicated that the helicopter may have what he thought was an engine problem and then he came to a hover and his blades folded up and he crashed.

If in fact it was a shaft separation, this is what I believe caused it. During heavy maneuvering there are variations in torque applied to the transmission. This is coupled with the dynamics of the rotor system when there is excessive leading and lagging (412 only) which are reflected in the driveline. On both the 212 and the 412 these variations in torque and the dynamics of the shaft cause it to whip at the center. This in effect shortens the shaft and introduces a high frequency vibration, which can exacerbate the whipping. The second problem is the location of the lift link that connects the transmission to the airframe. It is not located directly on center but instead is mounted off center and to the left of the longitudinal centerline of the helicopter. When the helicopter lifts off the ground the transmission will lean to the left and forward as it is mounted on rubber supports. In leaning to the left and forward it misaligns the drive shaft which under ideal conditions would run straight between the engine combining gearbox and the transmission. Maneuvering of the helicopter will react against the offset lift link and cause the transmission to whirl about the rotor shaft centerline thus further exacerbating the misalignment and the whipping of the drive shaft. It is my opinion that the high maneuvering loads coupled with the whipping of the shaft and the misalignment of the shaft with the transmission results in the disconnect. When the disconnect occurs all hell breaks lose as the shaft starts whipping causing a great deal of noise which can distract even the most experienced pilot.

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The Cat

[This message has been edited by Lu Zuckerman (edited 02 March 2001).]

[The Sultan]

Lu,

When I started here I thought your comments on aircraft which I had no experience on were intelligent and based on fact. As I have watched your posts on the V-22 and now the recent 412 accident, I now know you are full of it. Even the Ft Worth Star Telegram Bell haters saw through you and declined to publish your comments.

Questions:

Has the NTSB sought your expertise?

Have you ever seen a 212 or 412? If so when were you fired from one of these programs?

The Sultan

[sprocket]

Lu, without trying to speculate, that could account for the cowling pieces (cosmetic) debris, being found with rotor blade pieces. Anything going up through the top of the helicopter could take some blade and/or cowl with it. Although the reports are not clear as to what portions of blade had separated. I sincerely hope the actual cause is discovered quickly.

Further to your post, drive shaft failure can also be caused by loss of grease if the seal/boot fails.

I can remember the 205’s have the engine/T/M alignment deliberately offset to allow for Transmission movement, caused by the main rotor torque but their drive shafts are much shorter.

[Pac Rotors]

Lu,

Please leave your speculations at home. Dont treat this forum the way you did Just Helicopters. You got a lot of infighting going on the other forum and I for one would appreciate it if you would keep these sort of comments to your self.

PR

[willy the one]

From Lu's comments I assume he is refereing to tail rotor drive shafts and not engine to main gearbox drive. I have worked on 205 and 212 b.

[leading edge]

Helidrvr

I do not think that is it necessary for anybody to speculate on the causes of an accident that tragically involves loss of life.

I know that this is a rumour network but what we have here is not rumours, just pure speculation. 212s and 412s have been flying sucessfully ad safely for many years now and while there may always be the possibility of mecahnical failure, this does not mean that there is anything intrinsically wrong with the aircraft type.

Please padlock this thread until more information becomes available.

[Lu Zuckerman]

To: Pac Rotors

On a previous post you stated,” Now this makes me wonder what sort of major mechanical failure would have caused this. Any 412 operators out there have any thoughts”.

I was responding to your statement above. It is true that I am not a 412 operator nor am I a 412 driver but that fact does not invalidate my opinions. I did a great deal of research on the shaft separation problem on the 212 and the 412. First of all the only thing we all have to go on is the eyewitness reports that indicated that there was a lot of what was perceived as engine noise and the helicopter slowed down and the blades folded. It was my opinion that the aircraft suffered some type of power or drive failure and the pilot may have been distracted by all the commotion coming from the engine compartment and did not enter into an autorotation. Until the accident investigation is completed we have only to rely on conjecture and conjecture is what keeps this forum so interesting.

To: willy the one

I was addressing the shaft that runs from the combining gearbox to the transmission and not the tail rotor drive shaft.

To: Sprocket

I am aware of the problems related to loss of grease. This was a common problem on the 214 and it not only resulted in failure of the shaft couplings but it also caused the engine to surge due to the grease plating out on the engine inlet bell.

To: The Sultan

From your bio you are a test engineer and from your location in Texas I can only assume you work at Bell Helicopters. This would explain your defensive attitude. My posts on the V-22 were based on experience gained while working on the V-22 program at Boeing. In my posts it was understood by the participants on the various V-22 threads that my input was based on information that was five years old but has since proven to be just as valid now as it was then.
As I stated to Pac Rotors above I had done a lot of research on the shaft separation problem experienced by the USAF and the US navy on their helicopters.

If you want to state that my conclusions are incorrect relative to the V-22 and the B 212 / 412 shaft problem then don’t sharpshoot me from a position of anonymity offer a counter argument. Also, I would like to know if you are saying that there have been no shaft separation incidents on the 212 and the 412.

You asked if I had ever seen a 212 or a 412. I worked at Agusta as an engineering consultant for three years and I saw both helicopters being assembled from the ground up. If you question my experience on Bell helicopters I was the Manager of technical assistance for Bell Helicopter international and was responsible for first and second level maintenance on 900 helicopters most of which were AB 205s, AB 206s, AH 1Js and Bell 214s. You can add to that mix AS SH 3Ds and AB CH 47s. I was not fired from this position and after completing my 3-year contract I was asked to stay on for at least one more year. I was however fired from Boeing while working on the V 22. It seems that I kept bringing up the fact that the Prop Rotors when in the aircraft mode would place the hydraulic system in a situation where the demand on the system was higher than anticipated and would result in a degradation of the systems reliability. I did this on at least five occasions and I was told that it was a Bell problem and not a Boeing problem. They finally found a reason to cut my consulting contract short.

By the way, I understand that the last V 22 crash resulted from a failure of the hydraulic system.

Regarding my involvement with the Star Telegram it amounted to two conversations with one of the reporters. He also sent me a large packet of previously unpublished material relative to the V 22. I never completely read it but one thing that was stated was that the V 22 hydraulic system was not very reliable. He never asked me to comment in print nor did I offer. So, it seems that you were wrong on that point as well.

Regarding my involvement with the NTSB, I am deeply involved on the Robinson rotor separation / rotor incursion investigation.

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The Cat

[This message has been edited by Lu Zuckerman (edited 04 March 2001).]

[rotorhead4]

Lu, you did not deserve that flak, a forum is that of speculation and sharing thoughts and views, I have learned from you and others, I have the ability to decipher good and bad information and disregard the latter. I think you might have just tinkled on the wrong fire hydrant and the yard dogs are defending their territory..

[This message has been edited by rotorhead4 (edited 04 March 2001).]

[B Sousa]

"Please leave your speculations at home. Dont treat this forum the way you did Just Helicopters. You got a lot of infighting going on the other forum and I for one would appreciate it if you would keep these sort of comments to your self.

PR"
PR who the hell are you to dictate policy.
Pacific Rotors can ban Lu from their magazine, but it must not be doing too good as all I see is Pacific Rotors posting on everyone elses free forum. Is it that nobody reads the thing.....
Lu did have a lot of folks up in arms at Just helicopters, but I think they were all told to hit the delete button if they dont like it.
Tragically accidents kill people and break machines. That does not take away the fact that it will be years before the FEDs get a response or a clue as to what happened. If one pilot can gain enough information via specualation or whatever to save his ass, Im for it.
My two cents

[inthegreen]

I was just on another forum and read that the aircraft was supposedly doing an autorotational rpm check. That means they probably just made pitch link adjustments, or even replaced a blade. Maybe something was left loose?

[Pac Rotors]

Bert Sousa,

First off the comments were from my own opinion as per my post, didnt see where I said I was the boss of the forum. Just as Lu is entitled to make his thoughts known so am I as is everyone else.

Re your comments on the magazine actually it is going very well, obviously much to your dissapointment..

Yes I post on many of the forums but who gives a **** if they are free or not, or I suppose if I post on the pay ones then the magazine is better is it???? The forums are there to be used, right or wrong.

Oh and by the way I send copies of the magazine to Lu so before you think it is Lu bashing think again.

[B Sousa]

Bottom Line when you post as "Pac Rotors" It appears as you are posting on Behalf of the Magazine. You wont find Quality Magazines making posts such as yours. A simple change to one of anonymity or your own name would alleviate that heat.
Secondly, more power to you if the magazine is doing good. I dont care either way as it has little to do with Helicopter Industry information that I require.

[Pac Rotors]

Fair comment on the posting name and duly noted.

With regards to the content of the magazine some like it and some dont. We have a lot of subscribers who obviously like it and it gives them what they want, others such as yourselves dont like it and hey thats fine, its your decision.

Just because I post under my magazine name doesnt mean its not a quality magazine. Again thats only your opinion and its respected. We have great advertising and subscriber support so obviously we are a quality publication but all is in the eyes of the beholder.

PR