What is a Load and Trim Sheet?
A Load and Trim Sheet is the standardised document in which a pilot calculates and records the mass and centre-of-gravity (CG) of the aircraft before every flight.
Purposes:
- Evidence that the aircraft is within MTOM (Maximum Take-Off Mass) and CG limits.
- Documentation of the calculation for authority review.
- Aid for systematic prevention of computational errors.
Legal basis:
- Part-NCO.POL.105: the PIC must determine mass and balance before every flight.
- The format is not prescribed — each operator may use their own sheet provided all relevant items are captured.
Layout of a typical Load and Trim Sheet
┌──────────────────────────────────────────────────────────────┐
│ AIRCRAFT: D-EXAM (Cessna 172S) DATE: 27.05.2026 │
│ PILOT: Dominik Langer FLIGHT: EDFE → EDHL │
├──────────────────────────────────────────────────────────────┤
│ ITEM MASS (kg) ARM (m) MOMENT (kg·m) │
├──────────────────────────────────────────────────────────────┤
│ Basic Empty Mass 767.5 1.057 811.2 │
│ Pilot (Seat 1) 80.0 0.937 74.96 │
│ Co-Pilot (Seat 2) 75.0 0.937 70.28 │
│ Passenger 3 (Seat 3) 70.0 1.853 129.71 │
│ Passenger 4 (Seat 4) 60.0 1.853 111.18 │
│ Baggage Area 1 10.0 2.412 24.12 │
│ Baggage Area 2 5.0 3.099 15.50 │
│ Fuel (40 USG / 109 kg) 109.0 1.219 132.87 │
├──────────────────────────────────────────────────────────────┤
│ TOTAL 1176.5 1369.82 │
│ │
│ CG = TOTAL_MOMENT / TOTAL_MASS │
│ CG = 1369.82 / 1176.5 = 1.164 m (45.83 in) │
│ │
│ MTOM: 1 157 kg → TOTAL 1 176.5 kg → EXCEEDED ⚠ │
│ Fuel reduction needed: 19.5 kg = 6.6 USG less │
└──────────────────────────────────────────────────────────────┘
Mandatory elements
1. Registration, date, pilot, route.
2. Stations / items — all masses brought aboard:
- Basic Empty Mass (BEM) from the current weighing certificate.
- Crew (PIC + possible second pilot).
- Passengers with seat assignment.
- Baggage in the baggage compartments.
- Fuel in the tanks (type-specific).
- Optional: oil, water (e.g. potable water container).
3. Arms — in metres or inches measured from the datum:
- From the AFM/POH for each seat and baggage compartment.
- For some types different for different seat positions (forward/aft adjustable).
4. Moments = mass × arm.
5. Totals — total mass and total moment.
6. CG calculation: CG = total moment / total mass.
7. Check against limits:
- MTOM check: total mass ≤ MTOM. If exceeded: reduce load (fuel or baggage).
- CG check: CG within forward and aft limit for the actual mass. Read from the CG envelope diagram of the AFM.
8. Landing mass: re-check for the landing weight with reduced fuel (on longer flights CG may shift if tanks deplete unevenly).
Two methods to determine CG
CG envelope (example C172). Loading point inside the green area = OK.
Arithmetic method
- Tabular calculation as above.
- Pros: precise figures, documented, traceable.
- Con: error-prone when rushed.
Graphical method
- CG envelope diagram in the AFM:
- X-axis: CG position (arm from datum, or %MAC).
- Y-axis: total mass.
- Area: permitted CG envelope.
- The pilot plots the calculated (mass, CG) point. Point inside the envelope → OK.
- Pro: quick visual check.
- Con: diagram must be read accurately.
Some AFMs use a "Moment Index" instead of direct arms — Index = Moment / 1000 or 100.
Software/spreadsheet tools
In practice many pilots use:
- Excel sheets with formulas (self-built or club-provided).
- EFB apps (ForeFlight, Garmin Pilot, SkyDemon) with mass and balance module.
- Wall charts at the club with a pre-printed sheet.
Important: even if the app calculates, the pilot must sanity-check the result and document it.
Pitfall: keep BEM current
The Basic Empty Mass changes with:
- Modifications (new avionics, autopilot, EFB mount),
- Repairs (paint, fairings),
- Removal of components.
After each modification the aircraft must be re-weighed (by a maintenance shop with a weighing certificate). The weighing record in the logbook is the only binding source of BEM.