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

IMAPCR ’99
206. Terry Lutz said that software could be developed to correlate µ during an auto braking and
anti-skidding sequence for Airbus 320. Since autobraking decelerates at a fixed rate, the
distance travelled in that sequence could be used to establish the friction rate. Don Stimson
cautioned about the problems of using in-sequence data to derive surface conditions for
establishing the ideal friction rate. Jean-Claude Deffieux said that pilots could give valid
information based on experience.
207. Jim Wambold talked about a fibre optic system that measures maximum brake friction
during cycling. It could be an inexpensive system providing loading and traction information
on the aircraft and telemetring friction from the ground vehicles.
208. Tom Yager talked about other options being considered, such as associating runway surface
numbers with surface conditions other than just bare and dry, and reporting friction as a
percentage of stopping distance. He requested the guidance of the participants in promoting
these options among the aviation community.
209. Ernie Tangren felt that information on contaminant drag and crosswinds should be included
with the IRFI. He said that one parameter might not be enough to give what the flight crew
needs to know about the aircraft’s performance. He added that if the industry goes forward
with the IRFI, the hope may be that one number will solve the problems, and that this
should be reconsidered. Chet Collett mentioned that an airline-specific look-up table might
be the ideal format. Jim White countered that the IRFI would not be given as a single
number and nothing else, but runway condition reporting could be improved with friction
measurements. The IRFI is just one of the numbers to be given and that number would be
always on the same scale, not a comparison of apples and oranges.
210. Don Stimson cautioned that the first step is to achieve correlation between ground vehicles
and aircraft friction measures. Information must be useful to pilots and airport operators.
Even if aircraft performance cannot be determined, the IRFI is a good measure for the
airport to maintain safe operations. He said he believed that the program is heading in the
proper direction. If nothing else, if IRFI is the end result, that can be of great benefit to the
airport operator. He said he would like the work to get as close as possible to the ideal
situation of being able to correlate airplane performance. A panel member commented that
the Canadian Runway Friction Index was a good first step.
211. Paul Schmid added that to date runways have been categorized, and information has been
provided to operators about crosswinds and contaminant drag. What has yet to be improved
is aircraft performance correlation to friction, as has been done with the Canadian Runway
Friction Index. He said that all aircraft should be tested to get the desired correlation.
212. Charles Ayers wondered whetherTerry Lutz noted that the situation exists today, primarily
among the U.S. airlines. Some just do the wet calculations as a conservative way of doing
business. For example, the weight that can be carried is the weight for a wet runway, even if
the runway is dry. Not all airlines do that. He said that, by legislation, all airlines should be
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