Narrative:

Recently we have had issues with the RAT blades being damaged on deployment. Per upper management we were producing a video for training purposes. Several weeks back an investigation as to cause was determined and we were producing training videos. Today during discussions there was a second cause determined and we were developing a new procedure. Specifically on job card it states 'if the RAT is not aligned and not locked; do not continue with the RAT deployment.' it did not have a reference or procedure on how to correct the problem. We were working on developing the correction procedure.the problem: I was holding the release pin per the amm (aircraft maintenance manual). I had done this 3 time in the hour before the incident. As per the amm; the downlock pin is to be held out until you have pumped the RAT up 20 degrees. I thought it was at the same point as the other three times. When I released the pin we heard a sharp snap and stopped pumping the RAT. On inspection of the bore in the actuating collar showed damage at the forward leading edge. At this time I contacted an inspector to inspect the damage. There were no specs given in the cmm (component maintenance manual). Mechanic 1 used the borescope to take pictures with measurement to be sent to embraer for consideration. I contacted hour so I could get drug screened per our policies. I was following the current data on when to release the pin and had done so three successful times prior to the damage. The only thing I can surmise is that I was at a slightly different angle and misjudged the 20 degrees.I was following the current documentation but on the 4th time holding the release pin misjudged the RAT's position. Possibly due to a different stance causing my judgment to be in error. The release pin is in a difficult area to reach; there are cautions in bold that state not to keep your finger on the downlock pin until the RAT fully restows. Perhaps 30 degrees would give a safety margin for the pin and one's fingers.

Google
 

Original NASA ASRS Text

Title: Maintenance Technician and Manager reported; while producing a video for training purposes on an ERJ-170; the Maintenance Manager was pumping up the RAT (Ram Air Turbine) when the release pin was prematurely released by the Technician causing damage to the RAT.

Narrative: Recently we have had issues with the RAT blades being damaged on deployment. Per upper management we were producing a video for training purposes. Several weeks back an investigation as to cause was determined and we were producing training videos. Today during discussions there was a second cause determined and we were developing a new procedure. Specifically on job card it states 'If the RAT is not aligned and not locked; do not continue with the RAT deployment.' It did not have a reference or procedure on how to correct the problem. We were working on developing the correction procedure.The problem: I was holding the release pin per the AMM (Aircraft Maintenance Manual). I had done this 3 time in the hour before the incident. As per the AMM; the downlock pin is to be held out until you have pumped the RAT up 20 degrees. I thought it was at the same point as the other three times. When I released the pin we heard a sharp snap and stopped pumping the RAT. On inspection of the bore in the actuating collar showed damage at the forward leading edge. At this time I contacted an inspector to inspect the damage. There were no specs given in the CMM (Component Maintenance Manual). Mechanic 1 used the borescope to take pictures with measurement to be sent to Embraer for consideration. I contacted HR so I could get drug screened per our policies. I was following the current data on when to release the pin and had done so three successful times prior to the damage. The only thing I can surmise is that I was at a slightly different angle and misjudged the 20 degrees.I was following the current documentation but on the 4th time holding the release pin misjudged the RAT's position. Possibly due to a different stance causing my judgment to be in error. The release pin is in a difficult area to reach; there are cautions in bold that state not to keep your finger on the downlock pin until the RAT fully restows. Perhaps 30 degrees would give a safety margin for the pin and one's fingers.

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.