In airport planning, two runways have end coordinates (5000, 5000)–(8000, 7000) and (4600, 5100)–(7000, 5300). Determine the Airport Reference Point (A.R.P.) by averaging the geometric midpoints of all runways.

Civil Engineering Airport Engineering Difficulty: Medium
Choose an option
  • A
    (6500, 6000)
  • B
    (5800, 5200)
  • C
    (6150, 5600)
  • D
    (8000, 7000)
  • E
    (6200, 5550)

Answer

Correct Answer: (6150, 5600)

Explanation

Introduction:In airport engineering, the Airport Reference Point (A.R.P.) is a designated geographical position that represents the approximate center of the aerodrome. For a system of runways, a common approach is to compute the A.R.P. as the average of the midpoints of the individual runways, giving a balanced reference for charts, surveys, and navigation data.

Given Data / Assumptions:

  • Runway 1 endpoints: (5000, 5000) and (8000, 7000).
  • Runway 2 endpoints: (4600, 5100) and (7000, 5300).
  • A.R.P. taken as the mean of runway midpoints.

Concept / Approach:

The midpoint of a line with endpoints (x1, y1) and (x2, y2) is ((x1 + x2) / 2, (y1 + y2) / 2). The A.R.P. is then computed as the average of all runway midpoints when multiple runways exist.

Step-by-Step Solution:

Midpoint R1 = ((5000 + 8000) / 2, (5000 + 7000) / 2) = (6500, 6000)Midpoint R2 = ((4600 + 7000) / 2, (5100 + 5300) / 2) = (5800, 5200)A.R.P. x = (6500 + 5800) / 2 = 6150A.R.P. y = (6000 + 5200) / 2 = 5600Therefore, A.R.P. = (6150, 5600)

Verification / Alternative check:

The two midpoints lie reasonably close; their average must fall between them. (6150, 5600) lies between (6500, 6000) and (5800, 5200), confirming plausibility.

Why Other Options Are Wrong:

  • (6500, 6000): This is only the midpoint of Runway 1, not the average of both runways.
  • (5800, 5200): This is only the midpoint of Runway 2.
  • (8000, 7000): This is an endpoint, not a representative center.
  • (6200, 5550): A nearby estimate but not the exact computed average.

Common Pitfalls:

  • Choosing the midpoint of the longest runway instead of averaging all runways.
  • Accidentally averaging endpoints directly rather than averaging midpoints.

Final Answer:

(6150, 5600)

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