If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
number of rotor blades
Just a theoretical question that someone may be able to help with.
Alot of helicopters have only two rotor blades, ie:Robinsons, Bells, etc. Others have multiples, ie:dauphins with 4, Hughes etc. If a blade is thrown on a two blade, bend over and kiss your rear bye bye. What would happen if you had a 4, 5, or even 6 blade?Would you still be able to autorotate? I know the airframe would probably vibrate violently, but would it be survivable in an autorotate, or even low power to at least get to the ground. Have there been instances in the past where this has happened with a 2 blade. Thanks in advance. Rob Fonhof |
#2
|
|||
|
|||
If a blade is thrown on a two blade, bend over and kiss your rear bye bye.
What would happen if you had a 4, 5, or even 6 blade?Would you still be able to autorotate? The only thing I've ever heard about a survivable "blade loss incident" was on an early autogiro (Pitcairn, I think) The test pilot lost one of the four main rotorblades. The story has it that the opposing blade departed soon after the first and he was able to sucessfully land. I also remember that he never flew again. Tom |
#3
|
|||
|
|||
"Rob Fonhof" wrote in
: Just a theoretical question that someone may be able to help with. Alot of helicopters have only two rotor blades, ie:Robinsons, Bells, etc. Others have multiples, ie:dauphins with 4, Hughes etc. If a blade is thrown on a two blade, bend over and kiss your rear bye bye. What would happen if you had a 4, 5, or even 6 blade?Would you still be able to autorotate? I know the airframe would probably vibrate violently, but would it be survivable in an autorotate, or even low power to at least get to the ground. Have there been instances in the past where this has happened with a 2 blade. If you lose a blade, the imbalance will be so large as to take the transmission and everything attached to it out of the aircraft, most likely. It isn't survivable, just as losing a wing on an airplane isn't survivable, except in the most unusual of circumstances. -- Regards, Stan |
#4
|
|||
|
|||
Stan Gosnell wrote:
It isn't survivable, just as losing a wing on an airplane isn't survivable, except in the most unusual of circumstances. Stan..... Do you have any idea as to how often a blade has been thrown since the invention of the helicopter, gyro, etc. How about in the last decade. |
#5
|
|||
|
|||
A Hughes 369D lost a blade here in B.C. A few years back, it brought up a
whole bunch of issues with the blades. Here is report: http://www.tsb.gc.ca/en/reports/air/...8/a00P0208.asp Mike "Rob Fonhof" wrote in message ... Just a theoretical question that someone may be able to help with. Alot of helicopters have only two rotor blades, ie:Robinsons, Bells, etc. Others have multiples, ie:dauphins with 4, Hughes etc. If a blade is thrown on a two blade, bend over and kiss your rear bye bye. What would happen if you had a 4, 5, or even 6 blade?Would you still be able to autorotate? I know the airframe would probably vibrate violently, but would it be survivable in an autorotate, or even low power to at least get to the ground. Have there been instances in the past where this has happened with a 2 blade. Thanks in advance. Rob Fonhof |
#6
|
|||
|
|||
Curious Question wrote in
: Stan Gosnell wrote: It isn't survivable, just as losing a wing on an airplane isn't survivable, except in the most unusual of circumstances. Stan..... Do you have any idea as to how often a blade has been thrown since the invention of the helicopter, gyro, etc. How about in the last decade. It's pretty seldom, I suspect about the same frequency as airplanes losing wings. The only one I've heard of recently is a Sikorsky S76 which lost a blade (actually the blade broke off relatively close to the head) over the North Sea last year. All aboard were lost. The blade had been previously hit by lightning, and this coupled with a manufacturing defect caused it to fail. Losing a main rotor blade on a certificated helicopter is very rare, unless it's in conjunction with a collision, where the blades hit something and subsequently fail. I fly them for a living, and losing a MR blade is something I just don't worry about. The NTSB, and perhaps other national aviation safety agencies, publishes summaries of all aviation accidents in the US, going back to 1962, and it's searchable. You should be able to find what you're looking for there, at least for the USA. http://www.ntsb.gov/aviation/aviation.htm -- Regards, Stan |
#7
|
|||
|
|||
You will still have to bend over and kiss your behind and
I would suggest that you do it rather quick. "Rob Fonhof" wrote in message ... Just a theoretical question that someone may be able to help with. Alot of helicopters have only two rotor blades, ie:Robinsons, Bells, etc. Others have multiples, ie:dauphins with 4, Hughes etc. If a blade is thrown on a two blade, bend over and kiss your rear bye bye. What would happen if you had a 4, 5, or even 6 blade?Would you still be able to autorotate? I know the airframe would probably vibrate violently, but would it be survivable in an autorotate, or even low power to at least get to the ground. Have there been instances in the past where this has happened with a 2 blade. Thanks in advance. Rob Fonhof |
#8
|
|||
|
|||
About 2 years ago Herman Hospital in Houston, TX lost a BK117 due to a M/R
blade loss. They were on approach, I seem to recall about 100 ft AGL, and broke a TT strap (badly corroded). The M/R gearbox left the aircraft and all 3 souls were lost. This was the first time a blade had slung in the BO105 (same head) or BK117 history. Then I remember years ago Donald Trumps Agusta A109 lost a blade up in NY with several of his VP's aboard. All were killed. Then there were the M/R spindle problems with the S76 when it first came out. Your right though, a M/R separation is very, very rare. JC "Stan Gosnell" wrote in message ... Curious Question wrote in : Stan Gosnell wrote: It isn't survivable, just as losing a wing on an airplane isn't survivable, except in the most unusual of circumstances. Stan..... Do you have any idea as to how often a blade has been thrown since the invention of the helicopter, gyro, etc. How about in the last decade. It's pretty seldom, I suspect about the same frequency as airplanes losing wings. The only one I've heard of recently is a Sikorsky S76 which lost a blade (actually the blade broke off relatively close to the head) over the North Sea last year. All aboard were lost. The blade had been previously hit by lightning, and this coupled with a manufacturing defect caused it to fail. Losing a main rotor blade on a certificated helicopter is very rare, unless it's in conjunction with a collision, where the blades hit something and subsequently fail. I fly them for a living, and losing a MR blade is something I just don't worry about. The NTSB, and perhaps other national aviation safety agencies, publishes summaries of all aviation accidents in the US, going back to 1962, and it's searchable. You should be able to find what you're looking for there, at least for the USA. http://www.ntsb.gov/aviation/aviation.htm -- Regards, Stan |
#9
|
|||
|
|||
Subject: number of rotor blades
From: Stan Gosnell It isn't survivable, just as losing a wing on an airplane isn't survivable, except in the most unusual of circumstances. -- Regards, Stan I do know a an accident with a glider where the pilot lost a wing, spin down into a marsh with big fluffy trees and survied. It happened in Florida a few years ago and the glider was a 1-26. Craig |
#10
|
|||
|
|||
Hennie: With the vibration level you would have with a missing blade I
doubt if you could find your behind let alone aim a kiss at it. Having had one just slip out of track in flight was enough to tell me I would have had trouble kissing anything. Stu Fields "Hennie" wrote in message om... You will still have to bend over and kiss your behind and I would suggest that you do it rather quick. "Rob Fonhof" wrote in message ... Just a theoretical question that someone may be able to help with. Alot of helicopters have only two rotor blades, ie:Robinsons, Bells, etc. Others have multiples, ie:dauphins with 4, Hughes etc. If a blade is thrown on a two blade, bend over and kiss your rear bye bye. What would happen if you had a 4, 5, or even 6 blade?Would you still be able to autorotate? I know the airframe would probably vibrate violently, but would it be survivable in an autorotate, or even low power to at least get to the ground. Have there been instances in the past where this has happened with a 2 blade. Thanks in advance. Rob Fonhof |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Letter at end of flight number? | Laura | Piloting | 1 | December 17th 04 03:14 AM |
Pitts Number 1 registration number | Mirco | Aerobatics | 3 | December 4th 04 11:50 AM |
P-3C Ditches with Four Engines Out, All Survive! | Scet | Military Aviation | 6 | September 27th 04 01:09 AM |
p3/95 | [email protected] | Military Aviation | 1 | September 27th 04 12:27 AM |