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(a) A RESA must extend—
(1) to a distance of at least 90 metres from the end of the runway strip, and
(2) if practicable—
(i) to a distance of at least 240 metres from the end of the runway strip; or
(ii) to the greatest distance that is practicable between the 90 metres required in paragraph(a)(1) and the 240 metres required in paragraph (a)(2)(i).
(b) The width of a RESA must—
(1) be at least twice the width of the associated runway and be positioned symmetrically on either side of the extended centre line of the runway; and
(2) where practicable, be equal to the width of the graded portion of the associated runway strip.
(c) A RESA must be constructed to—
(1) provide a cleared and graded area to reduce the risk of damage to an aeroplane that undershoots or overruns the runway; and
(2) where practicable, be clear of any object which might endanger an aeroplane that undershoots or overruns the runway.
(d) A RESA must not penetrate the approach or take-off climb surface for the runway.
(e) If a RESA has a longitudinal slope—
(1) any downward slope must not exceed 5%; and
(2) slope changes must be as gradual as practicable; and
(3) abrupt changes or sudden reversals of slopes must be avoided.
(f) If a RESA has a transverse slope—
(1) any upward or downward slope must not exceed 5%; and
(2) slope changes must be as gradual as practicable.
