Weight and balance
Weight and balance records traced to engine-module file evidence
This source review asks whether the weight and balance statement still describes the aircraft the engine-module file documents. It serves records teams and asset managers when engine changes, QEC differences, or weight-affecting modifications have accumulated since the statement's last amendment. Every configuration change evidenced in the module file is tested for its weight consequence, and every amendment on the statement is tested for the change evidence behind it. Mismatches in either direction become exceptions for the trace file.
When this review is needed
- An engine change installed a unit with a different QEC build and the statement has not been revisited.
- Weight-affecting SBs or STCs were embodied at the last visit per the module file.
- A delivery or export condition requires a current, supported weight and balance statement.
- Successive amendments accumulated over years and their evidence trail has never been assembled.
The problem
Weight and balance drifts by accumulation. No single engine swap or bulletin seems worth reopening the statement, and the responsibility for noticing sits between the records office, engineering, and whoever ran the last reweigh. Years later the statement is formally current while resting on a chain of amendments whose supporting changes were never gathered in one place.
What gets reviewed
- Amendment history of the statement assembled against the configuration timeline in the module file
- Engine and QEC changes tested for weight and moment consequences and matching amendments
- Weight-affecting modifications from the mod status checked into the statement
- Reweigh events located and their reports matched to the values adopted
- Equipment changes recorded at shop visits traced for statement impact
- Current statement values checked as the arithmetic product of the amendment chain
Scope this review
Tell us the asset, the event, and the evidence in scope, and we will outline a focused first engagement.
Send a representative, redacted record set and we will scope the review.
What gets validated
- Each amendment cites a configuration change that the module file independently evidences
- No weight-affecting change in the file lacks a corresponding amendment or a documented no-effect rationale
- Engine swap records identify the QEC standard fitted, and the statement reflects that standard
- Values adopted at the last reweigh carry forward correctly through later amendments
- The statement in circulation is the latest amendment, with superseded versions identifiable
Evidence normally required
- The current weight and balance statement and its full amendment history
- Engine change and QEC configuration records from the module file
- Modification and STC status with weight data for embodied changes
- Reweigh reports within the period under review
- Shop-visit records noting equipment additions or deletions
Common discrepancies
- An engine change to a different QEC standard absorbed without any amendment
- Amendments computed from manufacturer nominal weights where actual fitted-equipment data existed
- A statement version in operational use that predates the latest amendment on file
- Weight-affecting bulletins embodied at a visit and never routed to the weight and balance owner
What is at stake
An unsupported statement fails quietly until a delivery, export, or audit forces the question, and the fallback is usually a reweigh on the critical path of a transaction. Where amendments were computed from wrong configuration assumptions, the correction can also cascade into performance and loading data that used the statement as input.
How the work runs
Assemble the change timeline
List every weight-relevant event the module file evidences across the review period.
Map the amendments
Set the statement's amendment history against that timeline, pairing changes with amendments.
Audit the arithmetic
Verify carried-forward values and the derivation of each amendment from its cited change.
Report the position
Deliver the reconciliation, exceptions, and a supported view on statement validity.
What the buyer receives
- An amendment-to-evidence reconciliation across the review period
- A two-way exception register for the trace file, covering unsupported amendments and unamended changes
- A recommendation on whether the evidence supports the current statement or a reweigh is warranted
Who uses the output
- Records and engineering staff who own the statement
- Delivery and export teams needing the statement defensible on a date
- Operators loading the aircraft on the statement's authority
How the work fits into the transaction or program
The statement consumes outputs from the modification, equipment list, and shop-visit records, which makes this review a natural successor to those checks: once the configuration picture is settled, its weight consequences can be audited in one pass rather than change by change.
Start with a single asset
Confirm release certificates and component traceability are complete.
Jurisdiction-specific considerations
FAA maintenance-record requirements under 14 CFR Part 43 and 91.417 reach weight and balance revisions made as part of maintenance or alteration, while EASA operators manage the statement within the continuing-airworthiness framework of Regulation 1321/2014 and applicable operational rules. Registry transfers matter here because reweigh interval conventions and amendment documentation styles differ, and an imported statement may need its basis restated for the receiving authority's expectations.
Regulatory limits
The review audits documentary support for the statement; it does not perform weighing, issue or approve an amended statement, or make loading or performance determinations. Producing a corrected statement remains with the organization authorized to do so.
What this review does not cover
- Physical weighing of the aircraft
- Preparation of load sheets or performance data
- Approval of amended weight and balance documents
Specific to this review
- Engine QEC differences are the classic silent weight change: the engine position looks identical on paper while the fitted standard differs by real mass.
- Amendment chains fail at ownership handoffs, where the incoming team adopts current values without inheriting the evidence behind them.
- Nominal-versus-actual weight substitutions rarely change any single amendment much, but they compound across a chain.
- A reweigh resets the arithmetic without curing the record: the superseded chain still needs to be coherent for the period it covered.
Sources
U.S. Government (eCFR). Maintenance recordkeeping content and approval-for-return-to-service requirements, including 43.9, 43.11, and Appendix B.
U.S. Government (eCFR). Records an owner or operator must keep, including total time in service, current status of life-limited parts, and AD compliance.
European Union / EASA. Continuing airworthiness, maintenance records, CAMO responsibilities, and the airworthiness review process in the EASA system.
Frequently asked questions
We reweighed two years ago. Does the earlier record still matter?
For the current values, the reweigh governs. For the record, the earlier chain still covers the period before it, and transactions or investigations that touch that period will read it. The review scopes effort accordingly: arithmetic rigor since the reweigh, coherence for the chain before it.
Relevant glossary terms
Related pages
Where this fits
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We will walk through your current state, the records or evidence involved, and a scoped first engagement.
Talk through the aircraft, records, evidence, deadline, and next useful step.