The organizational and technical questions considered by the Obstacle Clearance Panel (OCP) are reviewed. The panel has also studied flight paths which deviate from the ideal ILS final approach glidescope and analyzed data from many countries. A mathematical model has been developed from which curves indicating the lines of equal probability of deviation at each point during the approach can be derived. These data make it possible to postulate a new series of surfaces that can be used to identify the critical obstacles and thus to specify the minimum altitudes down to which the risk element can be held at a specified level during final approach. The acceptable cumulative risk level for all phases of the final approach has been quantified as one in ten million. A computer-derived method for calculating minimum approach altitudes was also devised. The OCP has proposed a classification of aircraft in 5 speed categories. Another principle introduced is that of the secondary zones in which the required vertical clearance can diminish progressively to either side of the nominal flight path reaching zero at the extreme edges.

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    86 Avenue Louis Casai
    1216 Cointrin-Geneva,   Switzerland 
  • Authors:
    • Tillmann, R
  • Publication Date: 1978-11

Media Info

  • Features: Figures; Tables;
  • Pagination: p. 1119-21
  • Serial:
    • Interavia
    • Volume: 33
    • Issue Number: 11
    • Publisher: Jane's Information Group
    • ISSN: 0020-5168

Subject/Index Terms

Filing Info

  • Accession Number: 00189737
  • Record Type: Publication
  • Source Agency: Interavia
  • Files: TRIS
  • Created Date: May 11 1979 12:00AM