Narrative:

I am an a&P mechanic that works on helicopters. The problem arose when I was asked to install some engine exhaust and tail rotor drive cowlings. The date was dec/xx/94, time of day was approximately XA00 hours. I installed the cowlings with help from 2 other individuals. I signed the supervisor block off on the work order for work done. The inspector and I asked a mechanic that was not involved in any of cowlings installations, to sign the work accomplished block off. Then the inspector signed off the inspector block. The next day I received a telephone call at approximately XB00 hours from the mechanic that had signed off the work accomplish block. He told me that the #2 tail rotor drive shaft had been sheared off, by a tool (awl) left by the tail rotor drive shaft. The shearing of tail rotor shaft was discovered on the first start. Main rotor was at approximately 80 percent when the mechanic noticed that the tail rotor blades were slowing down and then stopped, but main rotor blades were still turning. The mechanic then informed the pilot to shut down aircraft. No other damage was done to aircraft. Installed svcable #2 tail rotor drive shaft. There was bad judgement used on my part, inspector and the mechanic that signed off the work accomplished block. The main factors that caused incident, was pressure from management to get aircraft out, the number of people that were available to do the work. I believe that management should be liable as the a&P mechanic. Management should be held liable for their decision in pressuring their employees to do substandard work. Supplemental information from acn 292454: a school trained mechanic on the bell 214ST, installed the aft engine cowling and left a tool beside the tail rotor drive shaft under this cowling. He was the only qualified mechanic available so we were not sure how to sign off the installation of the work performed on our repair station work order. There are 3 slots to be signed. 1) for the mechanic, 2) for the supervisor and 3) for the inspector. The maintenance manager asked the school trained mechanic to sign as supervisor. We asked another mechanic to sign off the installation and I signed the inspector section. I being the inspector (but not trained on this aircraft). The next morning the person who signed as mechanic and the person who signed as inspector (me) were dismissed from the inspection department at a loss of $100. A month and the person caused the incident but signed as supervisor and school trained was fined $75. A month and a bad letter was put into his file.

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Original NASA ASRS Text

Title: LTT HELI TAIL ROTOR STOPPED TURNING DURING THE FIRST ENG'S START AFTER MAINT. TAIL ROTOR SHAFT HAD BROKEN DUE TO A TOOL LEFT BY MECH.

Narrative: I AM AN A&P MECH THAT WORKS ON HELIS. THE PROB AROSE WHEN I WAS ASKED TO INSTALL SOME ENG EXHAUST AND TAIL ROTOR DRIVE COWLINGS. THE DATE WAS DEC/XX/94, TIME OF DAY WAS APPROX XA00 HRS. I INSTALLED THE COWLINGS WITH HELP FROM 2 OTHER INDIVIDUALS. I SIGNED THE SUPVR BLOCK OFF ON THE WORK ORDER FOR WORK DONE. THE INSPECTOR AND I ASKED A MECH THAT WAS NOT INVOLVED IN ANY OF COWLINGS INSTALLATIONS, TO SIGN THE WORK ACCOMPLISHED BLOCK OFF. THEN THE INSPECTOR SIGNED OFF THE INSPECTOR BLOCK. THE NEXT DAY I RECEIVED A TELEPHONE CALL AT APPROX XB00 HRS FROM THE MECH THAT HAD SIGNED OFF THE WORK ACCOMPLISH BLOCK. HE TOLD ME THAT THE #2 TAIL ROTOR DRIVE SHAFT HAD BEEN SHEARED OFF, BY A TOOL (AWL) LEFT BY THE TAIL ROTOR DRIVE SHAFT. THE SHEARING OF TAIL ROTOR SHAFT WAS DISCOVERED ON THE FIRST START. MAIN ROTOR WAS AT APPROX 80 PERCENT WHEN THE MECH NOTICED THAT THE TAIL ROTOR BLADES WERE SLOWING DOWN AND THEN STOPPED, BUT MAIN ROTOR BLADES WERE STILL TURNING. THE MECH THEN INFORMED THE PLT TO SHUT DOWN ACFT. NO OTHER DAMAGE WAS DONE TO ACFT. INSTALLED SVCABLE #2 TAIL ROTOR DRIVE SHAFT. THERE WAS BAD JUDGEMENT USED ON MY PART, INSPECTOR AND THE MECH THAT SIGNED OFF THE WORK ACCOMPLISHED BLOCK. THE MAIN FACTORS THAT CAUSED INCIDENT, WAS PRESSURE FROM MGMNT TO GET ACFT OUT, THE NUMBER OF PEOPLE THAT WERE AVAILABLE TO DO THE WORK. I BELIEVE THAT MGMNT SHOULD BE LIABLE AS THE A&P MECH. MGMNT SHOULD BE HELD LIABLE FOR THEIR DECISION IN PRESSURING THEIR EMPLOYEES TO DO SUBSTANDARD WORK. SUPPLEMENTAL INFO FROM ACN 292454: A SCHOOL TRAINED MECH ON THE BELL 214ST, INSTALLED THE AFT ENG COWLING AND LEFT A TOOL BESIDE THE TAIL ROTOR DRIVE SHAFT UNDER THIS COWLING. HE WAS THE ONLY QUALIFIED MECH AVAILABLE SO WE WERE NOT SURE HOW TO SIGN OFF THE INSTALLATION OF THE WORK PERFORMED ON OUR REPAIR STATION WORK ORDER. THERE ARE 3 SLOTS TO BE SIGNED. 1) FOR THE MECH, 2) FOR THE SUPVR AND 3) FOR THE INSPECTOR. THE MAINT MGR ASKED THE SCHOOL TRAINED MECH TO SIGN AS SUPVR. WE ASKED ANOTHER MECH TO SIGN OFF THE INSTALLATION AND I SIGNED THE INSPECTOR SECTION. I BEING THE INSPECTOR (BUT NOT TRAINED ON THIS ACFT). THE NEXT MORNING THE PERSON WHO SIGNED AS MECH AND THE PERSON WHO SIGNED AS INSPECTOR (ME) WERE DISMISSED FROM THE INSPECTION DEPT AT A LOSS OF $100. A MONTH AND THE PERSON CAUSED THE INCIDENT BUT SIGNED AS SUPVR AND SCHOOL TRAINED WAS FINED $75. A MONTH AND A BAD LETTER WAS PUT INTO HIS FILE.

Data retrieved from NASA's ASRS site as of July 2007 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.