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View Full Version : EC-145 Loses T/R Counterbalance In Flight


MSP Aviation
18th Dec 2006, 11:52
here's the link. it's from a sim site, but the poster is the son of one of STARFlights pilots:

http://64.34.169.161/cgi-bin/ib3/ikonboard.cgi?;act=ST;f=1;t=10546

Flying Bull
18th Dec 2006, 16:41
Hi
here's the link. it's from a sim site, but the poster is the son of one of STARFlights pilots:

http://64.34.169.161/cgi-bin/ib3/ikonboard.cgi?;act=ST;f=1;t=10546

TX's for the information.
Haven't had anything similar with the BK117's we fly - which has the same tailrotorsystem - evenso our counterweights look a little bit different.

Greetings "Flying Bull"

Coconutty
19th Dec 2006, 08:09
Interesting -

The thread attached to MSP's forum discusses the TR counter weight "falling off in flight "

The pictures show that the counter balance weight is attached to a short shaft, and is secured by a split pin passing through machined holes in both the weight and shaft.

One would assume that the weakest point along the shaft would be the area around that hole, yet the shaft appears to have sheared completely through - inboard of where the hole is drilled for the pin.

And at the same time they had a Chips light :confused:

http://i34.photobucket.com/albums/d129/coconut11/Coconutty.jpg

NickLappos
19th Dec 2006, 08:57
It would be great to see a high res photo of that failure looking directly at the end. I would bet lots of crack striations, showing fatigue. At the typical tail rotor rpm, the crack would grow quickly. Very possibly a problem of manufacturing, or perhaps a ding while in service, where a flaw at the surface created a weakened area.