Assessing Aeroplane Landing Areas (ALAs) for Safe Operations

Understanding the criteria for assessing Aeroplane Landing Areas (ALAs) is crucial for ensuring safe take-off and landing operations. This section outlines the guidelines from the Civil Aviation Safety Authority’s (CASA) Advisory Circular AC 91-02, detailing the key factors and considerations involved in evaluating the suitability of ALAs.

Surface Conditions

To ensure the operability of an ALA, the surface conditions must meet certain standards:

Surface Quality: The surface should be firm and smooth enough to accommodate the aircraft, preventing damage and minimizing risk.
Drainage: Effective drainage systems are necessary to maintain surface integrity across different weather conditions. Poor drainage can lead to the deterioration of the landing area.
Maintenance: Continuous maintenance is required to preserve usability, which includes removing debris and controlling vegetation.

Dimensions

The physical attributes of an ALA must align with the operational requirements of the aircraft using it:

Width and Length: The ALA should possess adequate dimensions to allow safe aircraft operations. These dimensions depend on the type and weight of the aircraft.
Runway Slope: Minimal gradient is preferred, as steep slopes can adversely affect take-off and landing performance.

Approach and Departure Paths

Clearance and gradient in approach and departure paths are vital for safe operations:

Clear Paths: The flight paths should be free of obstructions, ideally following a straight path that aligns with the runway centerline.
Gradient: The gradients must be appropriate to facilitate safe ascent and descent of aircraft.

Obstructions

Managing potential obstructions is indispensable for maintaining safety:

Height Restrictions: Obstructions such as trees, buildings, and other structures in the vicinity of approach, departure paths, and surrounding areas must not interfere with flight paths.
Lighting and Marking: Proper illumination and marking of obstructions are necessary, particularly for night operations or in low visibility conditions.

Additional Considerations

Additional factors that influence the suitability of ALAs include:

Environmental Factors: Wind direction, wind strength, and local weather conditions should be evaluated as they can significantly affect aircraft operations.
Emergency Access: Provisions should be in place for emergency services to quickly access the ALA in the event of an incident.

Case Study: Runway Excursion at Avoid Island Aeroplane Landing Area

To illustrate the importance of ALA evaluations, consider the case of the Gippsland Aeronautics GA-8 incident at Avoid Island, Queensland, on 23 March 2017:

ALA Characteristics: Grass surface, 800 meters long with a slight rise and a vertical drop at the end.
Performance Calculation: Take-off distance was calculated to be 590 meters.
Issues: Environmental factors included wet grass and variable winds, leading to degraded performance and runway overrun.

Conclusion

This incident emphasizes that assessing ALA conditions and understanding environmental impacts is crucial for safety. Proper performance calculations and risk assessments are essential to prevent similar occurrences.

Sources

This comprehensive framework based on CASA’s guidelines ensures that pilots are equipped to determine the suitability of ALAs effectively, promoting safe and efficient aviation operations.