A line mechanic found a magnetic chip detector plug housing sheared-off flush with the main gearbox ...

Attributes
ACN	1035416
Time
Date	201209
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Daylight
Aircraft 1
Make Model Name	Jet/Long Ranger/206
Operating Under FAR Part	Part 135
Flight Phase	Parked
Component
Aircraft Component	Gearbox
Person 1
Function	Lead Technician
Qualification	Maintenance Airframe Maintenance Powerplant
Experience	Maintenance Lead Technician 5 Maintenance Technician 38
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

Aircraft was on a public relations [demonstration] assignment. Pilot reported slight transmission oil seepage on the transmission deck. Aircraft departed the event; arrived at home base. On inspection; I found that the magnetic chip plug was sheered off at its base. The internal check valve was still in place; preventing further transmission oil seepage. The part that sheered is installed at overhaul with a low torque of 75'- 125' inch-pounds and is not removed at any inspection. It appears to me that it was installed without a torque wrench. It requires a 3/4' socket to install. I had to use an adapter to get my 1/4' inch torque wrench on this socket. This torque is in the bell maintenance overhaul manuals. But it needs to be highlighted for emphasis because it is such low torque.

Original NASA ASRS Text

Title: A Line Mechanic found a Magnetic Chip Detector plug housing sheared-off flush with the Main Gearbox (MGB) transmission housing on a Bell 206L-1 helicopter. He had previously found two other Bell 206L-1 MGBs with the same condition.

Narrative: Aircraft was on a public relations [demonstration] assignment. Pilot reported slight transmission oil seepage on the transmission deck. Aircraft departed the event; arrived at home base. On inspection; I found that the Magnetic Chip Plug was sheered off at its base. The internal check valve was still in place; preventing further transmission oil seepage. The part that sheered is installed at overhaul with a low torque of 75'- 125' inch-pounds and is not removed at any inspection. It appears to me that it was installed without a torque wrench. It requires a 3/4' socket to install. I had to use an adapter to get my 1/4' inch torque wrench on this socket. This torque is in the Bell Maintenance Overhaul Manuals. But it needs to be highlighted for emphasis because it is such low torque.

Data retrieved from NASA's ASRS site as of July 2013 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.

A line mechanic found a magnetic chip detector plug housing sheared-off flush with the main gearbox (mgb) transmission housing on a bell 206L-1 helicopter. He had previously found two other bell 206L-1 mgbs with the same condition.