Chair Report

Appendix 3
RECOMMENDATIONS ON CUSTOMERS’ REQUIREMENTS
Customers have been segmented into 4 domains (groups). 1) Aviation, 2)Road,
3) Marine, 4) Public.
The requirements from the Aviation and Road Sectors are the strongest.
1) AVIATION SECTOR
The recommendations for the Aviation Sector were further segmented into different
categories:-
a) ICAO recommendations (including thresholds in Annex 3 both on standard and
recommended practices
(i) There is no need to improve the ICAO recommendations. There is rather
a need for improving their realization by the weather forecasters. This
implies that there is need to improve the forecasts to fulfill the ICAO
recommendations. ICAO recommendations seem to fulfill the needs of a
large part of customers (e.g. pilots) but not of some others (e.g. companies).
Aviation companies seems to be more demanding in terms of fog and low
cloud forecasts.
(ii) Aviation customers need direct forecasts of the parameters they actually
use (i.e. forecasts on RVR, forecasts for cloud base which are specific to
aerodromes or even specific to runways etc).
(iii) Another aspect is the accuracy of the forecast visibility and low cloud.
The findings regarding the accuracy required is given below.
(iv) Forecasts generally reflect points (e.g. aerodromes). However, there is a
need for spatially distributed forecasts on fog and low cloud.
(v) There is a need for improved schemes associating probabilities with
forecasts on low cloud and fog.
b) In-flight requirements (VFR)
(i) It is not clear from the questionnaires what are the VFR in-flight
requirements. However, some answers refer to the need of AIRMET and
GAMET and also to low level maps on fog and low cloud.
(ii) There is a requirement for spatial distributions type of forecasts for fog
and low cloud at the scale of 20 km for use by VFR flight.
c) In-flight requirements (IFR)
Cloud base is required as far as icing, turbulence, comfort and economy are
concerned. However, this is not well documented from the questionnaires
(only one answer was provided on this).
d) Leading time for forecasts . Period of validity
ICAO rules seem to be sufficient. However, improvement of the
dissemination time is recommended by some customers. Especially, air
traffic control requires special services regarding the period of forecasts, i.e.
shorter forecast validity.
e) Military requirements