# Load Securement: Restraint Methods, Locks, and Required Load Factors

> Understand cargo securement principles, tie-down and ULD-lock methods, and required directional load factors to prevent in-flight load shift.

- **Subject:** 031 — Mass and Balance
- **Section:** 031-06 — Cargo Handling
- **Topic code:** 031-06-03
- **Last reviewed:** 2026-04-01
- **Author:** Pablo Asensio Martínez
- **HTML version:** https://pilotsyllabus.com/en/mass-and-balance/cargo-handling/securement-of-load/

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## Importance of Securement
Cargo must be securely restrained so it does not move during:
*   Take-off and Landing (Acceleration/Deceleration).
*   Turbulence.
*   Emergency Landing.

Shifted cargo can dangerously affect the CG (stability) or damage the fuselage.

## Restraint Methods

### 1. Tie-down Straps and Nets
![Sailors attach a Cargo Net to a Puma Helicopter](https://upload.wikimedia.org/wikipedia/commons/e/e1/US_Navy_020729-N-2329T-002_Sailors_attach_a_Cargo_Net_to_a_Puma_Helicopter.jpg)
*   Used for bulk cargo.
*   Check the rating (capacity) of the straps and the attachment points (D-rings) on the floor.

### 2. ULD Locks
*   When loading containers or pallets, mechanical **floor locks** (latches) are raised to secure the ULD to the aircraft floor.
*   If a lock is broken (missing latch), that position may be unusable or weight restricted.

## Load Factors
The restraint system must be strong enough to withstand 'g' forces in all directions. Typical minimum ultimate load factors (Transport Category):
*   **Forward**: 9.0g (to protect passengers/crew in a crash).
*   **Sideways**: 1.5g.
*   **Upward**: 3.0g.
*   **Downward**: 6.0g.
*   **Aft**: 1.5g.

The cargo handling manual specifies the number of straps required based on the cargo mass and these load factors.

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Free study notes from pilotsyllabus.com. Not a substitute for training at an approved ATO.