A bell 206L-4 was dispatched and operated with the incorrect part installed in the main rotor drive.

Attributes
ACN	408553
Time
Date	199807
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzz
State Reference	US
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Jet Ranger Undifferentiated or Other Model
Operating Under FAR Part	Part 135
Flight Phase	other
Flight Plan	None
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
ASRS Report	408553
Person 2
Affiliation	company : air carrier
Function	other personnel other other personnel other
Qualification	other other : other
Events
Anomaly	aircraft equipment problem : critical non adherence : far non adherence : published procedure other anomaly other
Independent Detector	other other : unspecified
Resolutory Action	other
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

On jul/xx/98, I decided to change the freewheeling assembly on aircraft xyz as it was leaking. Called parts and asked for P/north 406-040-500-115. Parts man said he would check and get back to me. An hour later I called parts to check status. Parts man said he had a 406-040-500-123. Since the numbers were clear, I asked if it was a suitable substitute. He replied the computer says its a good number. I installed the -123, the aircraft was ground run, operations check flight complied with, and the aircraft was returned to service. On jul/xy/98, I was informed in person that the -123 part was not approved. The aircraft was finished for the day and had already landed. The aircraft is grounded, the -123 freewheeling assembly has been removed. Am waiting for the -115 assembly to be delivered in the morning. The aircraft flew its normal contract today, jul/xw/98. Flew 2.8 hours, with 5 starts and 6 takeoffs. Pilot reported no problem. Apparently, quality assurance people were not sure of the appropriate part number and had to call bell. Usually if a part has a higher number (newer), and can't be found in the parts book, parts is called to see if they have it listed as a suitable substitute. They have the latest and greatest listing. Their source, I believe they use the price list. If they cannot confirm the part, bell must be called.

Original NASA ASRS Text

Title: A BELL 206L-4 WAS DISPATCHED AND OPERATED WITH THE INCORRECT PART INSTALLED IN THE MAIN ROTOR DRIVE.

Narrative: ON JUL/XX/98, I DECIDED TO CHANGE THE FREEWHEELING ASSEMBLY ON ACFT XYZ AS IT WAS LEAKING. CALLED PARTS AND ASKED FOR P/N 406-040-500-115. PARTS MAN SAID HE WOULD CHK AND GET BACK TO ME. AN HR LATER I CALLED PARTS TO CHK STATUS. PARTS MAN SAID HE HAD A 406-040-500-123. SINCE THE NUMBERS WERE CLR, I ASKED IF IT WAS A SUITABLE SUBSTITUTE. HE REPLIED THE COMPUTER SAYS ITS A GOOD NUMBER. I INSTALLED THE -123, THE ACFT WAS GND RUN, OPS CHK FLT COMPLIED WITH, AND THE ACFT WAS RETURNED TO SVC. ON JUL/XY/98, I WAS INFORMED IN PERSON THAT THE -123 PART WAS NOT APPROVED. THE ACFT WAS FINISHED FOR THE DAY AND HAD ALREADY LANDED. THE ACFT IS GNDED, THE -123 FREEWHEELING ASSEMBLY HAS BEEN REMOVED. AM WAITING FOR THE -115 ASSEMBLY TO BE DELIVERED IN THE MORNING. THE ACFT FLEW ITS NORMAL CONTRACT TODAY, JUL/XW/98. FLEW 2.8 HRS, WITH 5 STARTS AND 6 TKOFS. PLT RPTED NO PROB. APPARENTLY, QUALITY ASSURANCE PEOPLE WERE NOT SURE OF THE APPROPRIATE PART NUMBER AND HAD TO CALL BELL. USUALLY IF A PART HAS A HIGHER NUMBER (NEWER), AND CAN'T BE FOUND IN THE PARTS BOOK, PARTS IS CALLED TO SEE IF THEY HAVE IT LISTED AS A SUITABLE SUBSTITUTE. THEY HAVE THE LATEST AND GREATEST LISTING. THEIR SOURCE, I BELIEVE THEY USE THE PRICE LIST. IF THEY CANNOT CONFIRM THE PART, BELL MUST BE CALLED.

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.