Service difficulty report · Bracket · Urocop EC130B4

Difficulty date
October 9, 2011
Submitted
September 14, 2015
Operation
General aviation
Make and model
Urocop EC130B4
Engine
Tmeca ARRIEL2B1
Part
Bracket
Part number
350A23422221
Condition
Broken
Location
Tailboom
Part time
389 hours
Stage of operation
IN
How discovered
9
Nature of condition
O
Precautionary procedure
K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

(CAN) UPPER LT PN 350A23-4222-21, 388.9 TOTAL HOURS. BROKEN IN PIECES. LOWER RT PN 350A23-4223-20, 789.9 TOTAL HOURS. CRACKED UPPER LEFT PN 350A23-4222-21, STOP DRILLED AT 789.9, REPLACED AT 876.7 TOTAL HOURS CRACKED. THIS IS THE FIRST OF 3 SIMILAR BRACKET, FAILED OR CRACKED. THE PARTS ARE USED TO LOCATE AND HOLD THE HORIZONTAL FIN IN PLACE. THERE ARE A FEW ISSUE WITH THIS INSTALLATION, THE BRACKETS ARE HELD IN LOCATION BY 5 SMALL BOLTS, ALL OF THE BOLTS WERE OVER TIGHTEN TO THE POINT THAT IT WAS ALMOST IMPOSSIBLE TO UNDO. THE BRACKETS ARE DRILLED. ALL OF THE HOLES IN THE BRACKET DID NOT HAVE THE EDGE OF THE HOLE CLEAN UP, PROVIDING A STRESS POINT. 3 OF THE 4 BRACKETS REPLACED CRACKED FROM THE BOLT HOLES OUT. THE BRACKETS ARE SHIMMED TO THE HORIZONTAL, 2 HARD GAPS, THAT WHEN THE THROUGH BOLT WAS TIGHTENED DOWN PUT FURTHER STRESS ON THE BRACKETS. THE BRACKETS, WHEN THE THROUGH BOLT IS PUT IN PLACE TO LOCATE THE HORIZONTAL FIN PLACES THE HORIZONTAL FIN TO BRACKET SURFACE AT AN ANGLE WHICH CAN NOT BE ADJUSTED LEVEL WITH DIFFERENTIAL SHIMMING WITHOUT JAMMING THE BOLT, MORE STRESS ON THE BRACKET.

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