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B737 maintenance technician reported that multiple cargo door repairs were made using an incorrect-thickness material.
| Attributes | |
| ACN | 1687907 |
| Time | |
| Date | 201903 |
| Local Time Of Day | 1201-1800 |
| Place | |
| Locale Reference | ATL.Airport |
| State Reference | GA |
| Aircraft 1 | |
| Make Model Name | B737-800 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Parked |
| Person 1 | |
| Function | Lead Technician |
| Qualification | Maintenance Airframe Maintenance Powerplant |
| Experience | Maintenance Lead Technician 15 Maintenance Technician 34 |
| Events | |
| Anomaly | Aircraft Equipment Problem Less Severe Deviation - Procedural FAR Deviation - Procedural Maintenance Deviation - Procedural Published Material / Policy |
Narrative:
I supplied a non-compliant part to an amt (aircraft maintenance technician) who then installed it onto a cargo door which then was used on our aircraft.currently [technician] is working a skin change on a 737 forward cargo door. While drilling up a pre-shaped skin it was realized that this skin was not fabricated for use on this mpn (model part number) or model door. Discussions [on] this with the crew; it came up that one of these pre-formed skins had been used in the past for [the] same model; door.a review of the records shows that earlier this year [technician] produced a 737-800 cargo door by installing a skin pre-fabricated by [company] drawing 52-xxxx-xxx.the skins fabricated per the engineering order/drawing are for a different mpn / model aircraft. This alone does not make these skin unusable but the fact that engineer based their approvals on a different mpn and aircraft model type when approving the material substitution; does.the original substitution approvals were for an original skin bonded from two layers of [aluminum]; substituted for one single thickness skin of for the aft cargo door of a 737-200/300.we installed this [modification] on a forward cargo door where the original skin was; the engineering order as stated does not cover forward cargo doors or 737-800s. To use the srm (structural repair manual) material substitution chart in an effort to allow for the substitution of a T42 skin vs a T3 skin requires additional thickness; due to the different heat treat properties.therefore the skin installed is an out of compliance situation.
Original NASA ASRS Text
Title: B737 Maintenance Technician reported that multiple cargo door repairs were made using an incorrect-thickness material.
Narrative: I supplied a non-compliant part to an AMT (Aircraft Maintenance Technician) who then installed it onto a cargo door which then was used on our aircraft.Currently [technician] is working a skin change on a 737 forward cargo door. While drilling up a pre-shaped skin it was realized that this skin was not fabricated for use on this MPN (Model Part Number) or model door. Discussions [on] this with the crew; it came up that one of these pre-formed skins had been used in the past for [the] same model; door.A review of the records shows that earlier this year [technician] produced a 737-800 cargo door by installing a skin pre-fabricated by [company] drawing 52-xxxx-xxx.The skins fabricated per the Engineering Order/Drawing are for a different MPN / model aircraft. This alone does not make these skin unusable but the fact that engineer based their approvals on a different MPN and aircraft model type when approving the material substitution; does.The original substitution approvals were for an original skin bonded from two layers of [aluminum]; substituted for one single thickness skin of for the aft cargo door of a 737-200/300.We installed this [modification] on a forward cargo door where the original skin was; the Engineering Order as stated does not cover forward cargo doors or 737-800s. To use the SRM (Structural Repair Manual) material substitution chart in an effort to allow for the substitution of a T42 skin vs a T3 skin requires additional thickness; due to the different heat treat properties.Therefore the skin installed is an out of compliance situation.
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.