Local loading limits & load distribution
Floor, compartment and restraint limits, and how the load is spread, are separate from total weight and CG.
Unairworthy if either breached (TC AIM AIR 4.4.2):
- Floor-load limit exceeded.
- Cargo restraint system not meeting aircraft's certification basis.
Local structural limits (TC AIM RAC 3.4.2):
- Baggage compartment or cabin floor placarded for own maximum load (weight-per-area), independent of gross weight or CG.
- Placard can apply when under gross weight and inside CG limits, due to limited strength of supporting structure (PHAK).
Loading rules (TP 1102):
- Load properly distributed.
- PIC loads per weight and balance info, which also limits where load may be placed (TP 1102, Centre of Gravity).
Load distribution (PHAK): matters even at same total weight and CG. Load dispersed onto long moment arms needs greater control forces to maneuver or hold level in turbulence.
| Loading | Handling |
|---|---|
| Full outboard wing or tip tanks | Tends to be sluggish in roll |
| Full nose and aft cargo bins | Less responsive to elevator |
Trap: checking only total weight and CG; a floor or compartment limit can be broken while under gross weight and in CG limits, and floor-load or restraint failure alone is unairworthy.
References
- TC AIM AIR 4.4.2
- TC AIM RAC 3.4.2
- TP 1102, Weight and Balance
- PHAK ch.5, Aerodynamics of Flight (Effect of Weight on Aircraft Structure; Effect of Weight on Flight Performance)