Airport engineering – clearway width requirement at runway end An aircraft has a lift-off distance of 2000 m. For safe take-off operations, the clearway provided at the end of the runway should not be less than what width (measured perpendicular to the runway centreline)?

Introduction / Context:
In airport geometric design, a clearway is an area beyond the runway end, free of obstacles, that allows an aeroplane to climb to a specified height in the take-off path. Examiners often test whether learners remember the standard dimensional requirements for clearways, especially the minimum clearway width that must be provided.

Given Data / Assumptions:

• Lift-off distance given: 2000 m (this does not change the minimum width requirement, which is a standard value).
• We consider a conventional instrument runway conforming to widely adopted standards.
• Clearway is centred on the runway centreline.

Concept / Approach:
Clearway length can vary based on performance needs and regulatory caps, but the minimum clearway width is standardized to ensure lateral obstacle clearance during initial climb. Many design manuals specify a clearway width not less than 150 m (often expressed as 500 ft). Where answers are given in metric with typical conversion rounding, the commonly used examination value is 152.5 m (exactly 500 ft).

Step-by-Step Solution:
Identify what is being asked: minimum clearway width, not length.Recall the codified minimum width: approximately 150 m, more precisely 500 ft.Convert 500 ft to metres: 500 * 0.3048 = 152.4 m, typically rounded to 152.5 m in objective tests.Select the closest option: 152.5 m.

Verification / Alternative check:
Airport design references routinely present the clearway width as 150 m nominal; where examination options are aligned with foot-based origins, 152.5 m is provided to reflect 500 ft.

Why Other Options Are Wrong:

• 145 m / 162.5 m / 172.5 m / 200 m: These do not match the standard minimum width requirement used for basic design checks; some are too small, others are unnecessarily large for the minimum criterion.

Common Pitfalls:
Confusing clearway length with width, or assuming that lift-off distance dictates a proportional clearway width. Length does vary with performance, but width minimum is a fixed standard baseline.

Final Answer:
152.5 m