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

IMAPCR ’99
192. Terry Lutz opened the discussion by stressing the need for performance data in aircraft flight
manuals (AFM). He noted that, while some aircraft, particularly small aircraft, working for
smaller carriers, carry all the performance charts, larger aircraft generally do not. They
receive weight information through the Aircraft Communication Addressing and Reporting
System (ACARS). What is needed in winter operations is information on runway condition
that is equivalent to that provided for wet runways. If that could be achieved, through
aggressive measurement and runway clearing and treatment procedures, then pilots could
have confidence in this information.
193. Al Mazur questioned whether the AFM have instructions to interpret the friction data to
help the pilot land safely. He raised the issue of whether pilots were using friction measures.
If they were not being used, are they needed?
194. Terry Lutz responded that friction measures are important and necessary for the pilot to
make conditional judgment on safe approaches and taxiing. Jean-Claude Deffieux agreed
that it is very important for the pilot to have friction measures, as a visual survey is not
adequate.
195. Tom Yager said that airport operators also have a vital interest in having accurate, up-to-date
friction information. They can adopt measures to bring friction levels up, such as applying
chemicals and grip, or they can close the runway.
196. Panel members agreed on the need to report friction coefficients. Discussion then moved to
the best and most efficient ways to report friction. Jim White said that the original reason for
CFME (Continuous Friction Measuring Equipment) was not for winter operations
particularly, it was for overall maintenance of the airport surface. So only so much value can
be extracted from CFME. Mr. Bjorn Bo felt that, given the inaccuracies and variability of
reporting (the lack of harmonization between ground and aircraft friction testers, the various
types of equipment used, and the dynamic conditions), it might be more useful to report
friction descriptively rather than in numbers. He suggested reports be done in terms of good,
fair, poor, or nil.
197. Tom Yager said that this system has been in use for the past 20 years and has not been
proven useful. Furthermore, he cautioned that qualitative assessments might not be
meaningful to pilots who have not had enough experience on wet runways. The descriptive
format could also lead to variable interpretations by the pilot or the operator. Classification
in ranges is far better than adjectives.
198. Leonard Taylor said that the IRFI should be converted to an index that would incorporate
both a qualitative number and a description of the runway. Another participant suggested
that a minimum level of friction for safe operations should be established. Paul McGraw
countered that airports would not be comfortable with one minimum measure. Armann
Norheim said that, as a part of the ICAO documentation, each airport should have a snow
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