Load Sheet and Trim Sheet Preparation
Purpose of the load sheet
The load sheet is the document that records the aircraft's mass and CG for a flight, signed by the person responsible (usually the loading supervisor and the commander). It shows DOM, traffic load, fuel, TOM, LM, ZFM, and the CG position at take-off and landing. The trim sheet (or balance chart) is the graphical or tabular tool used to determine CG position and verify it lies within the envelope.
Contents and sequence
A typical load sheet contains:
- Basic empty mass and DOM
- Distribution of passengers by zone and cargo by hold
- Total traffic load
- Fuel (block, trip, taxi)
- Mass limits (MTOM, MLM, MZFM)
- Calculated TOM, LM, ZFM
- CG position (% MAC) at TOM and LM
- Signature blocks
Using the trim sheet
Loads are entered by compartment, each with a known arm or index. The cumulative index is plotted on the trim envelope, which shows forward and aft limits across the mass range. The point must fall inside the envelope for both take-off and landing.
Traps
- Last-minute changes (LMC): a small change may still push CG outside limits; LMC limits must be respected.
- Using the wrong trim sheet for the aircraft variant.
- Forgetting to plot the landing condition as well as take-off.
- Signing a load sheet with arithmetic errors - the commander remains responsible.
- Confusing index with % MAC.
Worked example
DOM index 45.0; passenger index 12.0; cargo index 8.0; fuel index 10.0. Total index = 75.0. On the trim envelope at TOM 12,450 kg, index 75.0 lies between forward limit 70 and aft limit 82, so the loading is acceptable. If cargo were moved aft, the index would rise and could exceed 82.
Rule of thumb
Always verify both TOM and LM points on the envelope; a loading valid at TOM can be invalid at LM.