The Boost Pump With the Wrong Serial Number
During a 200-hour inspection on 5Y-LND, a Cessna 208B leased from a European lessor, the engine-driven fuel boost pump was removed after 180 hours in service for low output; the overhaul interval is 1,200 hours. Stores issued a replacement pump. The pump body is stamped with the manufacturer's part number, but the release document accompanying it is an FAA Form 8130-3 that quotes a part number with a different dash number, and the serial number on the tag does not match the pump. Stores explains that the pump came from a lot bought at a Nairobi auction together with other Caravan spares, that the dash number is 'just a superseded version', and that the previous pump came from the same lot. The lease requires OEM parts with traceability to the manufacturer. The aircraft is due to depart tomorrow on a cargo run and the operator is pressing for release.
1. Decide whether the pump may be fitted and released, and set out the immediate actions the engineer must take.
Read the worked answer
Governing principle. Certification rests on the identity of the part and an unbroken traceability chain from manufacture to installation. A release document that does not match the part in front of you evidences nothing about that part.
Assessment. The dash number differs and the serial number on the tag does not match the pump body. Two independent mismatches mean the document cannot be associated with this unit. Stores' verbal assurance about supersedure is not evidence; supersedure must be shown in the manufacturer's parts catalogue or in a written OEM statement, and even then the serial number must reconcile.
Immediate actions. Quarantine and tag the pump as a suspected unapproved part, do not fit it, preserve the tag and packaging, notify the quality manager, raise a suspected unapproved part report to KCAA, and trace every other part from the same auction lot, including the pump that has just been removed after only 180 hours.
Release decision. The aircraft must not be released with this pump. A compliant, fully traceable pump must be sourced and certified before the CRS is signed; the cargo run is not a factor that can be weighed against airworthiness.
2. Assume the documentation is later corrected and the pump is confirmed to be a PMA part approved for the Caravan. May it be fitted? Distinguish the airworthiness question from the contractual one.
Read the worked answer
Airworthiness. A PMA part is acceptable if it is approved for that specific aircraft model and part number, is eligible for the installation, is not excluded by a critical-component or life-limited restriction, and is accompanied by a release document acceptable to KCAA that ties to the actual unit. The installer must also confirm that continuing airworthiness information exists for it. On those facts, fitment can be airworthy.
Contract. The lease is a separate obligation. A requirement for OEM parts with manufacturer traceability is a commercial term that airworthiness approval does not satisfy. Fitting a PMA part without the lessor's agreement can breach the lease, affect return conditions and create liability that lands on the operator and ultimately on the engineer who concealed it.
What the engineer should do. Separate the two questions in the record, obtain the lessor's written position before fitment if time allows, and document the airworthiness justification for whichever part is installed.
Trap to avoid. Treating 'airworthy' as 'permitted', or treating a lease as if it could ground an otherwise airworthy aircraft.
3. What reports and records are required in this case, whichever way the decision goes?
Read the worked answer
Suspected unapproved part report to KCAA, describing the pump, part and serial numbers, the mismatched tag, the supplier and the auction lot, with photographs and copies of the documents. This protects other operators who may hold parts from the same lot.
Quarantine record showing the date, location, reason and person responsible, plus the disposition once the matter is resolved.
Stores records covering the receiving inspection and the rejection or release decision, since the receiving inspection is where the mismatch should have been caught.
Aircraft records. A technical log entry for the removal of the original pump and its reason, the work order for the replacement, and a note that no CRS was issued until traceability was established.
Notifications. The operator and the lessor, and a service difficulty report if the early failure at 180 hours against a 1,200-hour interval suggests a fleet trend.
Retention. All of the above kept for the period required by the regulations, legible and retrievable, because the lessor and KCAA may both ask for them.