clifford
8th Jan 2001, 00:51
Ladies and Gentlemen,
My best friend, Desmond Casey, and a mechanic were killed in a MD-520N accident 10-25-99. I am frustrated with how long it is taking to come out with a final report from the NTSB. I understand they are probably understaffed and overwhelmed, but 15 months is too long. The lives of many more of us may be at stake. I would like to tell you my understanding of what happened and ask you pilots and department managers to at least ask a lot of questions before buying an aircraft with the NOTAR system. I will tell you now my information will probably not be technically perfect but that is not the point of my writing to this forum.
Desmond took off on the 25th for a test flight back to San Jose International. They had diagnosed that the yaw SAS was inop and they were going to fly it to their maintenance base. The night before Desmond and another officer were flying when they had some uncontrolled yaw movements. The afternoon of the accident just a couple of miles from the airport at cruise speed the aircraft started spinning uncontrollably to the left. (As reported by an observer on the ground) From what I have been told investigators found that a cable had failed where it was swedged. This failure, I believe, caused the pedal to go full left at which point the assembly would not allow any right pedal application. The cable assembly controls three things I believe. The pitch of the fan that blows air down the tail boom, the left vertical fin, and finally the coffee can assembly in the back, which directs the air. If I am wrong about these things please correct me. I am an ATP rated helicopter pilot with S-76 and UH-60 time, but I have no PIC 520N time. I am also not an A&P. From what I have been told supposedly MD knew about the cracks in the cable swedges, but believed that they only affected the other end of the cable.
At this time please take a minute and think about the emergency handed my friend. Spinning uncontrollably to the left. The fan that blows the air down the tail boom is connected to the transmission. As long as those blades are turning there is going to be air blowing that tail around to the right. There goes auto rotating! Does anyone know of another helicopter where one failure leaves you with no way of controlling the aircraft? I have also heard that MD says that full pedal could be controlled in flight by maintaining forward airspeed and doing a run on landing. I don’t believe that. How are you going to keep your forward airspeed with that kind of a yaw rate? If MD would like to rig an aircraft up for that kind of a failure I would like be there to see it.
If any of you could help me understand what happened or correct any errors I might have passed on I would welcome your comments. I would also like to say that San Jose PD (which I am not affiliated with) was treated very poorly after the accident by McDonald Douglas. If you notice they purchased an EC-120 not another MD-520.
I submit this to the forum so that others will question and think about the design and possible flaws of the system. My only goal is to see that Desmond’s life was not lost in vain. I understand they have had an emergency AD on the cables. They found hundreds that were cracked from what my sources have told me. But does this change the fact that one failure in a cable assembly could kill you. There is a large lawsuit pending but I would appreciate any comments from parties with first hand knowledge.
Still missing you Des.
My best friend, Desmond Casey, and a mechanic were killed in a MD-520N accident 10-25-99. I am frustrated with how long it is taking to come out with a final report from the NTSB. I understand they are probably understaffed and overwhelmed, but 15 months is too long. The lives of many more of us may be at stake. I would like to tell you my understanding of what happened and ask you pilots and department managers to at least ask a lot of questions before buying an aircraft with the NOTAR system. I will tell you now my information will probably not be technically perfect but that is not the point of my writing to this forum.
Desmond took off on the 25th for a test flight back to San Jose International. They had diagnosed that the yaw SAS was inop and they were going to fly it to their maintenance base. The night before Desmond and another officer were flying when they had some uncontrolled yaw movements. The afternoon of the accident just a couple of miles from the airport at cruise speed the aircraft started spinning uncontrollably to the left. (As reported by an observer on the ground) From what I have been told investigators found that a cable had failed where it was swedged. This failure, I believe, caused the pedal to go full left at which point the assembly would not allow any right pedal application. The cable assembly controls three things I believe. The pitch of the fan that blows air down the tail boom, the left vertical fin, and finally the coffee can assembly in the back, which directs the air. If I am wrong about these things please correct me. I am an ATP rated helicopter pilot with S-76 and UH-60 time, but I have no PIC 520N time. I am also not an A&P. From what I have been told supposedly MD knew about the cracks in the cable swedges, but believed that they only affected the other end of the cable.
At this time please take a minute and think about the emergency handed my friend. Spinning uncontrollably to the left. The fan that blows the air down the tail boom is connected to the transmission. As long as those blades are turning there is going to be air blowing that tail around to the right. There goes auto rotating! Does anyone know of another helicopter where one failure leaves you with no way of controlling the aircraft? I have also heard that MD says that full pedal could be controlled in flight by maintaining forward airspeed and doing a run on landing. I don’t believe that. How are you going to keep your forward airspeed with that kind of a yaw rate? If MD would like to rig an aircraft up for that kind of a failure I would like be there to see it.
If any of you could help me understand what happened or correct any errors I might have passed on I would welcome your comments. I would also like to say that San Jose PD (which I am not affiliated with) was treated very poorly after the accident by McDonald Douglas. If you notice they purchased an EC-120 not another MD-520.
I submit this to the forum so that others will question and think about the design and possible flaws of the system. My only goal is to see that Desmond’s life was not lost in vain. I understand they have had an emergency AD on the cables. They found hundreds that were cracked from what my sources have told me. But does this change the fact that one failure in a cable assembly could kill you. There is a large lawsuit pending but I would appreciate any comments from parties with first hand knowledge.
Still missing you Des.