Jimf671 posted:
Quote:
Originally Posted by
Daylite 
Speaking with chc technical department, it now seems the gearbox in the aircraft was only changed yesterday.
That is consistent with the available flight history showing 5 short local flights 26th and 27th.
Depending on local procedures, then, it is possible that everything from the gearbox mounting structure upwards was removed and replaced. Most ops would take the blades off the head to begin with. Anyhow, in the midst of doing all the removal/replacement, there are opportunities for human error. Reason I mention that is that if it was a gearbox issue which initiated the action, one would assume there wouldn't be vibration problems after the re-install, so what were the 5 maintenance flights for? I made the assumption they were MTF's because Jimf671 wrote that they were short.
Anecdote re a local practice that I ran into at Ft Rucker one day. They had a UH-60A which had driven evryone a bit crazy re vibrations and it had been down awhile. I went down with a dynamics engineer to see if we could help. Put the vib gear on and got ready to fly. Our engineer pulled me aside and told me that all the pushrods had no safety wire on. Asked the civilian test pilot I was to fly with and he told me they always did that and only safetied the rods after they were done. Told him that my insurance agent forbade me to fly without safety wire on the pushrods. There is more to this particular story, but although this would be a long shot, its one of the variations that might have taken place here.