TP 13579 PROCEEDINGS of the 2nd International Meeting ... - UQAC

IMAPCR ’99
49. Tables of stopping distances are generated that include the effect of reverse thrust or
propeller discing.
50. When asked whether the data could be used for 0°C with melting snow/ice, Mr. Croll
indicated that the tables were good for Falcon 20. However, the response from the airlines
has been that the tables are conservative.
51. On the question of testing for significance, Mr. Croll suggested that while the distribution
was normal, no real test of significance has been applied. He further stated that the
methodology developed was not an exact science. The results are presented for guidance
only and are applicable to snow and ice. The effect of slush was not known.
52. A question was asked about the legal status. Paul Carson replied that the methodology was
published in the Aeronautical Information Publication (AIP). It is for information and
guidance only and is not a regulation.
53. Concerning the effect of aircraft size, Mr. Martin observed that the size is not significant – if the
methodology is correct.
54. For operational use a hierarchy exists for the use of data, i.e., from AFM to AOM to third
party to the AIP.
55. Responding to a question about the obligation of airport operators in Canada to report
CRFI, Mr. Mazur informed the audience that no such requirement exists.
Statistical Analysis of Stopping Performance on Wet Runways
56. Ken Balkwill, Consulting Aerodynamicist and Chairman, Performance Committee, ESDU
International, U.K., presented a statistical analysis of stopping performance on wet runways.
57. Starting with existing data derived from flight tests, Mr. Balkwill first presented the friction
database in graphic form and went on to describe a three-zone physical model and a
statistical model.
58. Some of the factors that affect braking on wet runways are:
• speed;
• macro- and micro-texture;
• water depth;
• tire pressure, temperature, and state of wear;
• tire constituents and structure tread pattern;
• braking system efficiency, torque capability, and wheel slip ratio;
• braking effort.
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