Narrative:

During a routine 800 hour inspection of AS350-B2 eurocopter a determination was made to replace the tail rotor gearbox due to an output seal leak. A gearbox of the same part number was ordered. A serviceable gearbox was received and installed. It was a repaired unit from xx eurocopter. The aircraft was released for check flight. A very large amount of paperwork was sent after the 800 hour inspection was completed to update the status sheets prior to return to service. This included appropriate paper work for the replacement gearbox.it was later discovered that a bevel gear within the gearbox had too many hours on it to be used on an AS350-B2 although the manufacturer repaired it. The gearbox was eligible to be used on an AS350-B only. I did not realize that the bevel gears had multiple time limits based on aircraft model. I did not see any paperwork or external markings stating it was limited to a 'B' model. After the updated status sheets came out errors were noted in the component section. The old and replaced gearboxes were still listed together. I discussed this with the site mechanic for this aircraft and he discussed this with the auditors. We assumed that the auditors would eventually get all of the paperwork and status sheets corrected. The numbers were so out of the ordinary that we thought it was a math error. In the mean time the aircraft was flown with a gear that had exceeded it's time between overhaul (tbo) for a 'B2' aircraft. Upon realizing that this had occurred; maintenance was notified and the aircraft was grounded.would suggest the group who repairs the gearbox should make note on the paperwork and the unit itself of which aircraft it is eligible to be used on.

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Original NASA ASRS Text

Title: A Maintenance Supervisor with Inspection Authority (IA) described the amount of paperwork involved with an 800 hour Inspection of an AS350-B2 Eurocopter that included replacement of the tail rotor gearbox. A bevel gear within the serviceable gearbox was later found to have exceeded it's Time Between Overhaul (TBO) for the AS350-B2. Aircraft was grounded.

Narrative: During a routine 800 hour Inspection of AS350-B2 Eurocopter a determination was made to replace the tail rotor gearbox due to an output seal leak. A gearbox of the same part number was ordered. A serviceable gearbox was received and installed. It was a repaired unit from XX Eurocopter. The aircraft was released for check flight. A very large amount of paperwork was sent after the 800 hour Inspection was completed to update the status sheets prior to return to service. This included appropriate paper work for the replacement gearbox.It was later discovered that a bevel gear within the gearbox had too many hours on it to be used on an AS350-B2 although the manufacturer repaired it. The gearbox was eligible to be used on an AS350-B only. I did not realize that the bevel gears had multiple time limits based on aircraft model. I did not see any paperwork or external markings stating it was limited to a 'B' Model. After the updated status sheets came out errors were noted in the component section. The old and replaced Gearboxes were still listed together. I discussed this with the site Mechanic for this aircraft and he discussed this with the Auditors. We assumed that the Auditors would eventually get all of the paperwork and status sheets corrected. The numbers were so out of the ordinary that we thought it was a math error. In the mean time the aircraft was flown with a gear that had exceeded it's time between overhaul (TBO) for a 'B2' aircraft. Upon realizing that this had occurred; Maintenance was notified and the aircraft was grounded.Would suggest the group who repairs the gearbox should make note on the paperwork and the unit itself of which aircraft it is eligible to be used on.

Data retrieved from NASA's ASRS site as of April 2012 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.