Narrative:

I was contacted yesterday by my regional maintenance. I was told about this incident and told to write a statement. The aircraft this is in regards to had to make a precautionary landing after losing tail rotor control in flight. Hardware from the pitch control linkage fell off in flight. The hardware in question should not have been removed. I had no idea the other mechanic that worked with me removed this particular bolt. It is not necessary to remove this bolt to remove the pitch change mechanism. I failed to see that this bolt was not cotter pinned when I was conducting a [visual check] of the work performed by this other mechanic. In my defense; I had no idea the other mechanic removed this bolt. He failed to tell me that he removed this bolt while conducting this maintenance. I want to bring this issue to light because I am very upset about the issue. Someone or all of the crew could have been killed because of this failure. I believe there should be more in-depth procedures in place to track maintenance so that when two mechanics are doing a pass down; nothing gets missed. Myself and another mechanic worked on [the helicopter] a couple weeks prior.I received a call from maintenance control to work on [the helicopter]. Maintenance control said that the pilot was reporting binding in the tail rotor pedals. I arrived and started troubleshooting the binding. I found that the control rod was rubbing where it goes through one of the ribs on the airframe. I reported this to maintenance control and was told to flip the control rod 180 degrees and that should fix the problem. I started the disassembly process. I removed the forward bolt from the control rod just behind the hat rack. I dropped the bolt upon removal and spent the next hour trying to find it. I was getting close to timing out shortly after I arrived; so maintenance control had [another mechanic] on the way to relieve me. [The other mechanic] arrived and I gave him a pass down. I told him how far I had gotten in the process and what remained to be worked on. I left to get rest at a hotel.I came back in later that morning. [The other mechanic] told me he spent a good 3 hours finding that bolt I dropped. He was in the middle of replacing the tail rotor boot when I arrived. He had the vertical fin removed and was disassembling the tail rotor pitch change linkage. He informed me that he had flipped the control rod. Had all hardware torqued and cotter pinned. He was trying to get the boot changed out before he timed out. He informed me that he forgot to bring torque stripe; so I provided him some. I inspected his work on the control rod and I got on a computer to sign off that task. I went back in the hangar and he was installing hardware for the linkage. At no time did I see him remove the bolt in question. To my knowledge; he removed the two bolts on the idler link. I believe that is what it is called off the top of my head. At no time did I look at the bolt in question or notice a problem with it. It was not necessary to remove that bolt to remove the pitch change mechanism. After [he] torqued the hardware and installed the cotter pins; I installed the torque stripe on the two bolts that [he] removed. He asked me if I had safety wire because he forgot to bring some. I got some safety wire and I installed the safeties on the boot. [The other mechanic] was about timed out so I told him to sign off his work so I could [document] it. While he was signing off the discrepancy for the boot; I installed the vertical fin. I torqued the hardware and applied torque stripe. [He] timed out and left. I installed the tail rotor gear box covers.I'm not exactly sure on the chain of events after this; but maintenance control can verify if I get it wrong. I believe after I installed the gear box covers I had the pilot look over the aircraft; then we did a ground run to check beep range and do idle speed adjustments. I was in contact with my senior base mechanic. I contactedhim to help me with the idle speed adjustments. After everything was adjusted properly I signed off the paperwork for that discrepancy and put the aircraft back in service so the pilot and I could conduct an operational check flight. No defects were noted and the aircraft worked perfectly. Upon landing I finished paperwork. Upon approval of paperwork from maintenance control; the pilot put the aircraft back in service.I just want to say that I am very relieved no one was injured in this incident; and in the future I will conduct a much more thorough [visual inspection]. Not just of the particular items and hardware worked on; but also the entire surrounding area. I am very upset about this whole issue. What we do as mechanics is very important; and I do not want anybody getting hurt.

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Original NASA ASRS Text

Title: Maintenance Technician reported that a Bell 206 helicopter lost tail rotor pitch control.

Narrative: I was contacted yesterday by my Regional Maintenance. I was told about this incident and told to write a statement. The aircraft this is in regards to had to make a precautionary landing after losing tail rotor control in flight. Hardware from the pitch control linkage fell off in flight. The hardware in question should not have been removed. I had no idea the other mechanic that worked with me removed this particular bolt. It is not necessary to remove this bolt to remove the pitch change mechanism. I failed to see that this bolt was not cotter pinned when I was conducting a [visual check] of the work performed by this other mechanic. In my defense; I had no idea the other mechanic removed this bolt. He failed to tell me that he removed this bolt while conducting this maintenance. I want to bring this issue to light because I am very upset about the issue. Someone or all of the crew could have been killed because of this failure. I believe there should be more in-depth procedures in place to track maintenance so that when two mechanics are doing a pass down; nothing gets missed. Myself and another mechanic worked on [the helicopter] a couple weeks prior.I received a call from Maintenance Control to work on [the helicopter]. Maintenance Control said that the pilot was reporting binding in the tail rotor pedals. I arrived and started troubleshooting the binding. I found that the control rod was rubbing where it goes through one of the ribs on the airframe. I reported this to Maintenance Control and was told to flip the control rod 180 degrees and that should fix the problem. I started the disassembly process. I removed the forward bolt from the control rod just behind the hat rack. I dropped the bolt upon removal and spent the next hour trying to find it. I was getting close to timing out shortly after I arrived; so Maintenance Control had [another mechanic] on the way to relieve me. [The other mechanic] arrived and I gave him a pass down. I told him how far I had gotten in the process and what remained to be worked on. I left to get rest at a hotel.I came back in later that morning. [The other mechanic] told me he spent a good 3 hours finding that bolt I dropped. He was in the middle of replacing the tail rotor boot when I arrived. He had the vertical fin removed and was disassembling the tail rotor pitch change linkage. He informed me that he had flipped the control rod. Had all hardware torqued and cotter pinned. He was trying to get the boot changed out before he timed out. He informed me that he forgot to bring torque stripe; so I provided him some. I inspected his work on the control rod and I got on a computer to sign off that task. I went back in the hangar and he was installing hardware for the linkage. At no time did I see him remove the bolt in question. To my knowledge; he removed the two bolts on the idler link. I believe that is what it is called off the top of my head. At no time did I look at the bolt in question or notice a problem with it. It was not necessary to remove that bolt to remove the pitch change mechanism. After [he] torqued the hardware and installed the cotter pins; I installed the torque stripe on the two bolts that [he] removed. He asked me if I had safety wire because he forgot to bring some. I got some safety wire and I installed the safeties on the boot. [The other mechanic] was about timed out so I told him to sign off his work so I could [document] it. While he was signing off the discrepancy for the boot; I installed the vertical fin. I torqued the hardware and applied torque stripe. [He] timed out and left. I installed the tail rotor gear box covers.I'm not exactly sure on the chain of events after this; but Maintenance Control can verify if I get it wrong. I believe after I installed the gear box covers I had the pilot look over the aircraft; then we did a ground run to check beep range and do idle speed adjustments. I was in contact with my senior base mechanic. I contactedhim to help me with the idle speed adjustments. After everything was adjusted properly I signed off the paperwork for that discrepancy and put the aircraft back in service so the pilot and I could conduct an operational check flight. No defects were noted and the aircraft worked perfectly. Upon landing I finished paperwork. Upon approval of paperwork from Maintenance Control; the pilot put the aircraft back in service.I just want to say that I am very relieved no one was injured in this incident; and in the future I will conduct a much more thorough [visual inspection]. Not just of the particular items and hardware worked on; but also the entire surrounding area. I am very upset about this whole issue. What we do as mechanics is very important; and I do not want anybody getting hurt.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.