BK-117 destroyed
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BK-117 destroyed
This German Helicopter (BK-117)was on a EMS Mission on Wendnesday when direct after touchdown, a piece of the building ( in the background) became loose by the downwash and was sucked in the rotor.
As you can see severe damage to what was the Rotor.
4 persons including the doctor where injured, but not serious. He had the helmet off too early!!!
Parts of the machine flying around injured other people as well.
I´m stunned, how little is left, glad everybody walked away!!!!
Fly save, watch out!!
Enzo
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We were discussing crashworthy strength on another thread. The piece of the building caused a sudden rotor stoppage, as if the rotor struck a big rock. Note how the transmission was ripped from the helo, because the old crash standards didn't require the strength to have the helo stay together in such a strike. In a way, the blades are stronger than the transmission mounts. The BO-105 family was designed to the old FAR 27 standards.
In a more crash worthy machine, the blades would have broken off, but the fuselage would have stayed unharmed, and the transmission would have stayed put, all to protect the cage the occupants are in.
When buying a helicopter, it is quite right to value this new strength (in at AB-139 and the S-92) as an improvement over previous designs.
Of course, helicomparitor has told you that window size is more important than the structural strength of the helicopter, and its crashworthiness!!!
In a more crash worthy machine, the blades would have broken off, but the fuselage would have stayed unharmed, and the transmission would have stayed put, all to protect the cage the occupants are in.
When buying a helicopter, it is quite right to value this new strength (in at AB-139 and the S-92) as an improvement over previous designs.
Of course, helicomparitor has told you that window size is more important than the structural strength of the helicopter, and its crashworthiness!!!
Which raises questions in my mind about what the effect of an identical accident on an EC145 might be.
I know that the items below the engine/tail boom have been changed and it might be that the rotor blades have been changed to a design that will shatter more readily but the fact appears to remain that there is a basic 117 still up top.....
Would it be possible to incorporate a 'fracture line' between the old and new structures to facilitate a measure of crashworthiness... and might it be a safe option to have a heavy roof section [engines/blades etc] set loose in that manner?
.... Nick...?
I know that the items below the engine/tail boom have been changed and it might be that the rotor blades have been changed to a design that will shatter more readily but the fact appears to remain that there is a basic 117 still up top.....
Would it be possible to incorporate a 'fracture line' between the old and new structures to facilitate a measure of crashworthiness... and might it be a safe option to have a heavy roof section [engines/blades etc] set loose in that manner?
.... Nick...?
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PANews,
I had to look carefully at the EC web page and the FAA site for the Type Certificate Data Sheet to see that there really is no EC145, there is the BK-117 C-2, which is called the EC 145. It is the same helo, with a greatly grandfathered set of design and safety rules, fundamentally no different than the original BK-117.
Retrofitting the strength of the basic structure is nearly impossible, and always impractical. The way it is expressed in FAR/JAR is the number of G's the airframe must withstand when dropped, and there is no way to beef up a system without total redesign. You have to literally beef up every part, every frame, clip and perhaps every rivet in the structure. That is why the 225 begs off modern crashworthiness - the cost and weight penalties are awesome. I would imagine that the redesign and requalification of the fuselage of a part 29 aircraft could easily be 150 to 200 million dollars, all of whch has to be recouped with an increase in sales price. It is far easier to change the name and the paint job, and pray nobody actually reads pprune.
This is not to say that the aircraft is in any way unsafe. It does say it is less safe, as an absolute fact, than a newer design.
Wouldn't it be interesting if the FAA/JAA officials were made to require that the certification basis of the aircraft be made part of the adverts and brochures, like cigarette ads.
The New Belchfire 277X, the finest flying machine ever produced*
*actually it is a retreaded repainted 1968 model, with steel dashboard and no seatbelts, caveat emptor!
I had to look carefully at the EC web page and the FAA site for the Type Certificate Data Sheet to see that there really is no EC145, there is the BK-117 C-2, which is called the EC 145. It is the same helo, with a greatly grandfathered set of design and safety rules, fundamentally no different than the original BK-117.
Retrofitting the strength of the basic structure is nearly impossible, and always impractical. The way it is expressed in FAR/JAR is the number of G's the airframe must withstand when dropped, and there is no way to beef up a system without total redesign. You have to literally beef up every part, every frame, clip and perhaps every rivet in the structure. That is why the 225 begs off modern crashworthiness - the cost and weight penalties are awesome. I would imagine that the redesign and requalification of the fuselage of a part 29 aircraft could easily be 150 to 200 million dollars, all of whch has to be recouped with an increase in sales price. It is far easier to change the name and the paint job, and pray nobody actually reads pprune.
This is not to say that the aircraft is in any way unsafe. It does say it is less safe, as an absolute fact, than a newer design.
Wouldn't it be interesting if the FAA/JAA officials were made to require that the certification basis of the aircraft be made part of the adverts and brochures, like cigarette ads.
The New Belchfire 277X, the finest flying machine ever produced*
*actually it is a retreaded repainted 1968 model, with steel dashboard and no seatbelts, caveat emptor!
Nick, i wouldn't describe the accident as a "sudden rotor stoppage". A sheet from the building damaged the blades at 100%. There are radial forces up to 12 tons on the blades of a BK 117 at 100%. The now working unbalance after the sheet struck, ripped off the MGB from the deck in a few seconds. The MGB was found 6m away. Parts of the blades still connected to the MR hub. Thats a scenario i'm sure you have seen during ground test some times. I believe there is a sikorsky video junking a chinook during ground test. I'm not sure if the much more modern and new designed ships are able to keep up such a situation. Indeed i believe not. On such forces it isn't possible to construct a more safe system. Also the AH 64, much more though designed encountered problems with this scenario.
This was an older BK 117 designed more than 20 years ago. But i want to mention the cabin area including cockpit is absolutely undamaged. The tail boom is still on the frame and not bended, only the rear crosstube is broken. I don't think the a/c is to much damaged linked to such a scenario. Ok, sure the deck and the frame are bended, it's a million damage at least. All the guys walked away, only the doc is injured because he doesn't weared his helmet and striked his head. I believe it's better to stay on the ground with a naked MGB deck and a broken crosstube, than to find the MGB coming through the deck inbound the crew. I think this accident have shown the BK 117 as a well designed and rough a/c.
And to the questions about the EC 145. The EC 145 is a BK 117C2. But the new cabin strengthened due to the use of carbon fibres withstands higher breaking loads.
This was an older BK 117 designed more than 20 years ago. But i want to mention the cabin area including cockpit is absolutely undamaged. The tail boom is still on the frame and not bended, only the rear crosstube is broken. I don't think the a/c is to much damaged linked to such a scenario. Ok, sure the deck and the frame are bended, it's a million damage at least. All the guys walked away, only the doc is injured because he doesn't weared his helmet and striked his head. I believe it's better to stay on the ground with a naked MGB deck and a broken crosstube, than to find the MGB coming through the deck inbound the crew. I think this accident have shown the BK 117 as a well designed and rough a/c.
And to the questions about the EC 145. The EC 145 is a BK 117C2. But the new cabin strengthened due to the use of carbon fibres withstands higher breaking loads.
Last edited by tecpilot; 17th Dec 2005 at 09:15.
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Come on Techo.!!
If anything of substance hits the Main or Tail Rotor whilst they are at 100%, then its a Sudden Stoppage. [Fullstop].
I guess you don’t realize that whilst the EC 145 has a EC ident….it is mainly built in Japan???, by Guess who????
The powers of the Global Smokescreen……
If anything of substance hits the Main or Tail Rotor whilst they are at 100%, then its a Sudden Stoppage. [Fullstop].
I guess you don’t realize that whilst the EC 145 has a EC ident….it is mainly built in Japan???, by Guess who????
The powers of the Global Smokescreen……
Per definition a sudden stoppage absolutely. But as i wrote "i wouldn't describe" i meant it isn't the "classic" sudden stoppage with a sudden strength decrease in RPM. Sorry!
This is a scenario the MGB goes away may be nearly without a RPM drop. 90-100% as long as the MGB was connected to the engines, means may be 2-5 seconds. It's the same like shooting away an outer part of a blade in combat.
And this was a german BK 117
The BK 117 from the land of the rising sun have no certification in Germany
This is a scenario the MGB goes away may be nearly without a RPM drop. 90-100% as long as the MGB was connected to the engines, means may be 2-5 seconds. It's the same like shooting away an outer part of a blade in combat.
And this was a german BK 117
The BK 117 from the land of the rising sun have no certification in Germany
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German 117.......come on....where was your EC stallion really made...???
Don't ever believe the EC 145 is a EC thingo....research its point on manufacture.....you will be surprised......
Don't ever believe the EC 145 is a EC thingo....research its point on manufacture.....you will be surprised......
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And I have seen photos of a S-76B that had 2 blades blown off it by the wind!! Yes they were tied down, it definitely looks weird with 2 little stubs left where the blades once were. BTW the cabin was untouched.
Lets not forget that 76 dynamics have departed in more than one case WITHOUT hitting anything.
And what will an S76D be? A "new" old helicopter?
I think EC have done a good job with the 145 within the bounds of what they can.
Ref the EC 145 yes it is a BK117C2 and the K always stood for Kawasaki. Yes there is an equivalent to the EC 145 buiilt in Japan and is a 117C2. The German assembled one is an EC 145 and the aircraft is assembled in Donauworth even if the frame is made in Japan. This has always been the case. BFD. I don't know how it can be economic in either country.I think EC have done a good job with the 145 within the bounds of what they can. The whole cockpit section is nearly identical to a 135.
The head on a 117 is the same as a 105 so it is plenty more than 20 years old!
BTW Kawasaki make the MGB in a MD900 don't they?
MD 500 Frames were once made in Korea for the US delivered aircraft.
The EC 135 is a cleaned up BO 108.
AS350's are now being built in Mississippi.
EC 120's are made partly in China and Singapore.
I think it is called "globalisation". Check the "Big Mac" index in the Economist magazine.
Lets not forget that 76 dynamics have departed in more than one case WITHOUT hitting anything.
And what will an S76D be? A "new" old helicopter?
I think EC have done a good job with the 145 within the bounds of what they can.
Ref the EC 145 yes it is a BK117C2 and the K always stood for Kawasaki. Yes there is an equivalent to the EC 145 buiilt in Japan and is a 117C2. The German assembled one is an EC 145 and the aircraft is assembled in Donauworth even if the frame is made in Japan. This has always been the case. BFD. I don't know how it can be economic in either country.I think EC have done a good job with the 145 within the bounds of what they can. The whole cockpit section is nearly identical to a 135.
The head on a 117 is the same as a 105 so it is plenty more than 20 years old!
BTW Kawasaki make the MGB in a MD900 don't they?
MD 500 Frames were once made in Korea for the US delivered aircraft.
The EC 135 is a cleaned up BO 108.
AS350's are now being built in Mississippi.
EC 120's are made partly in China and Singapore.
I think it is called "globalisation". Check the "Big Mac" index in the Economist magazine.
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Hey guys, this is not defaming a good helicopter, it is pointing out that safety rules change with time, and if you buy an old design made recently, you get old safety rules.
How can you tell? The Type Certificate Data Sheet tells you, no matter when the aircraft was built, how old its design rules are.
tecpilot and Giovanni, here is a link to the TCDS for the 117 C2, which is a grandfathered BK-117. It shows that the rules the 117 C2/EC 145 meets are not particularly new, and many are original to the original 117:
http://webpages.charter.net/nlappos/H13EU.pdf
I really love it when someone like Giovanni drops back to 8 years old and says something like, "Well, so's your father!!"
In fact the S-76 family is grandfathered, also. If you don't accept that new aircraft designs are safer than old aircraft designs, too bad, there is always Santa Clause, too.
I must point out that internal Sikorsky basic crash design requirements are tougher than FAR, and match US military requirements for all its models in production. An S-76 can have this kind of strike and not damage its structure, it was proven quite a few years back when one was landed into a rig catwalk, where it struck the steel structure with all main blades at full power (the pilot was trying to escape) and the sealant around the main transmission was not even broken, the transmission was removed by simply removing the bolts.
How can you tell? The Type Certificate Data Sheet tells you, no matter when the aircraft was built, how old its design rules are.
tecpilot and Giovanni, here is a link to the TCDS for the 117 C2, which is a grandfathered BK-117. It shows that the rules the 117 C2/EC 145 meets are not particularly new, and many are original to the original 117:
http://webpages.charter.net/nlappos/H13EU.pdf
I really love it when someone like Giovanni drops back to 8 years old and says something like, "Well, so's your father!!"
In fact the S-76 family is grandfathered, also. If you don't accept that new aircraft designs are safer than old aircraft designs, too bad, there is always Santa Clause, too.
I must point out that internal Sikorsky basic crash design requirements are tougher than FAR, and match US military requirements for all its models in production. An S-76 can have this kind of strike and not damage its structure, it was proven quite a few years back when one was landed into a rig catwalk, where it struck the steel structure with all main blades at full power (the pilot was trying to escape) and the sealant around the main transmission was not even broken, the transmission was removed by simply removing the bolts.
Nick,
For someone who claims to be an expert on all aspects of helicopters I am surprised you are so ignorant of basic dynamics.
If the helicopter had been "better" and only lost a blade and not the whole rotor/tranmission the occupants would have been either severly injured or killed by the 1/rev from the resulting imbalance. The fact that the rotor departed almost instantly saved them from worse.
The Sultan
For someone who claims to be an expert on all aspects of helicopters I am surprised you are so ignorant of basic dynamics.
If the helicopter had been "better" and only lost a blade and not the whole rotor/tranmission the occupants would have been either severly injured or killed by the 1/rev from the resulting imbalance. The fact that the rotor departed almost instantly saved them from worse.
The Sultan
Impressive pictures...
As described before the MGB is gone. The frame is in stable condition and safed the guys. Luckily the ship don't overturned. With a steadier MGB fixation i believe the ship would have done an overturn. And in this case... may be we could only look to an outburned a/c.
Interesting detail!!! The white rotor brake lever is to see pulled and blocked. Hey guys, in cases like these it isn't necessary to execute the post flight checklist 
As described before the MGB is gone. The frame is in stable condition and safed the guys. Luckily the ship don't overturned. With a steadier MGB fixation i believe the ship would have done an overturn. And in this case... may be we could only look to an outburned a/c.
Interesting detail!!!
The white rotor brake lever is to see pulled and blocked. Hey guys, in cases like these it isn't necessary to execute the post flight checklist
Last edited by tecpilot; 17th Dec 2005 at 16:09.
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These guys were just lucky, in that the aircraft was obviously close to the ground. Whether the gearbox stayed on or off isn't the main point. Either way, this major FOD incident could easily have killed them all if they were just a little higher.
P.S. Nick - where are those "new" S-76 fuselages being made these days? D model too?
P.S. Nick - where are those "new" S-76 fuselages being made these days?
D model too?
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tecpilot said, "With a steadier MGB fixation i believe the ship would have done an overturn. And in this case... may be we could only look to an outburned a/c."
While I fully disagree with that observation ("I am glad the aircraft came apart, it is better that way.....") it does show a strength of the BK-117 C2 because it DOES meet the latest crashworthy fuel design requirements, so it would have a much lower probability of burning in a post crash fire.
Please understand my post, it is to use this crash to illustrate that the exact design requirements of a particular machine contribute to its safety, and that later designs, meeting newer requirements are safer. Beware of clever name changes, and look at the underlying data to judge.
While I fully disagree with that observation ("I am glad the aircraft came apart, it is better that way.....") it does show a strength of the BK-117 C2 because it DOES meet the latest crashworthy fuel design requirements, so it would have a much lower probability of burning in a post crash fire.
Please understand my post, it is to use this crash to illustrate that the exact design requirements of a particular machine contribute to its safety, and that later designs, meeting newer requirements are safer. Beware of clever name changes, and look at the underlying data to judge.
Nick, i don't sign "I am glad the aircraft came apart, it is better that way.." The guys were absolutely lucky and accident scenarios are different. Shy is right, if they were a little bit higher ...
Nick,
I suspect that there's a tad of thread creep: the aircraft is a BK-117B, or B2 but definitely not a C2, so the strength of the original design is well proven. When I ripped the tail rotor gear box out of my 117, after landing and spreading the cross tubes everything was still functioning to the extent that I put the engines to ground idle, and started a 2 minute countdown for the turbines. Until I realised the clonking noise was the tail rotor drive shaft (or the remains of....) thrashing around in the vertical fin 
The strength of the BK hull is very impressive, and this reinforces my opinion
it does show a strength of the BK-117 C2 because it DOES meet the latest crashworthy fuel design requirements, so it would have a much lower probability of burning in a post crash fire
The strength of the BK hull is very impressive, and this reinforces my opinion
BK's are TUFF!
Nick,
I know of one BK that got itself killed during a low-level right hand turn that got out of hand....it was zipping along close to the ground...around and down it went and smashed into a road embankment going full chat. End result was one broken arm. I would suggest anyone trying that in a Bell product might not have fared quite so well.
We all know of the Bell Guillotine on skids!
I know of one BK that got itself killed during a low-level right hand turn that got out of hand....it was zipping along close to the ground...around and down it went and smashed into a road embankment going full chat. End result was one broken arm. I would suggest anyone trying that in a Bell product might not have fared quite so well.
We all know of the Bell Guillotine on skids!
