63. Mr. Gresham Cookeasked the President of the Board of Trade to what extent the statistics of monitoring aircraft for noise at Heathrow are vitiated by low-flying aircraft not being monitored by reason of their being off-course.
§ Mr. J. P. W. MallalieuVery little, if at all. The aircraft are normally observed by the Noise Monitoring Unit, and any significant departure from the routes laid down—as published in theAir Pilot—is taken up with the operator.