XN000022-1974-02-22 — Page 3

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ay 22, 1974

Work on the initial phase of grooving is expected to start in

May. This work will last about three months. The estimated cost is

about $1.3 million.

These grooves will be so spaced as to allor supplementary grooves

to be cut in between them at a later stage should this prove necessary,

Fuch of this initial work will have to be carried out at night,

and this will mean the closure of the runway for part of the night during

the three-month period.

The anoberman recalled that the overlay of the runway surface

was completed last August. The old surface had been grooved for the

last 18 months of its operational life.

"It is impossible to groove a new overlay immediately because

the surface is not sufficiently hard, and it is very important to get

the timing and phasing right in order to avoid working abortively on

premature prooving which might subsequently break up and possibly lead to

prolonged and complete closure of the runway. Ilence the importance of the

tests.

"We are very satisfied with the quality of the nov surface. As

regards its frictional characteristics, the M-reter tosto show that by

international standards the runway rates as good in dry weather and average in

very wet weather.

"This means that the frictional standard in wet weather may be

marginally lower than that of the old runway surface, but against this must

be set an improvement in the crossfall drainage standard and the elimination

of puddles or 'birdbath' arcas (where shallow layers of water gathered) on

the old runway.

•

/A spokesman