WAFSOPSG/5-IP/8
18/8/09
WORLD AREA FORECAST SYSTEM OPERATIONS GROUP (WAFSOPSG)
FIFTH MEETING
Paris, France, 16 to 18 September 2009
Agenda Item 9: Any other business
DEPICTION OF FRONTAL SYSTEMS OF SIGWX CHARTS
(Presented by IFALPA)
SUMMARY
Information in picture about frontal systems is a safety issue.
With amendment 74 of ICAO Annex 3, issued and effective November 7 2007
Frontal systems were no longer required to be depicted on SIGWX Charts.
Essential information like Frontal systems, low and high pressure systems are
not depicted in current SIGWX charts. Showing only CB's and omitting all
other cloud types may lead to wrong assumptions by pilots.
By dropping Frontal systems from SIGWX charts in Annex 3 they are no
longer being considered on any new developments as can clearly be seen on
the recent development of the Gridded Forecast project.
Short-sighted cutting of vital data increases the risk of a total loss of an aircraft
significantly. Weather is basic to flying, weather affects the success of the
operation. Weather is a major contributing if not causal factor in almost all
landing and approach accidents and whilst the investigation of AF 446 is
ongoing it is clear that weather was a contributing factor.
Action by the meeting is in paragraph 6.
(4 pages)
533565500
WAFSOPSG/5-IP/8
1.
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INTRODUCTION
1.1
With amendment 74 of ICAO Annex 3 — Meteorological Service for International Air
Navigation , issued and effective November 7, 2007 Frontal systems were no longer required to be
depicted on SIGWX Charts. Frontal systems are perhaps the factor which generates the most adverse
weather conditions. Whilst showing predicted phenomena such as cloud cover which can or cannot be
accurate, there is no substitution to a wind direction change or temperature variance that acknowledges
that a Frontal system has been crossed and thus the associated weather can be expected.
1.2
Frontal systems were dropped from SIGWX charts prior to the events of September 11
when access to the MET-office was readily available. In today’s security environment there is an
increasing restrictive freedom of movement which makes visiting the MET-office especially at non home
base airports ever more complicated. Thus lacking this valuable tool to compare predictive versus actual
conditions to determine the safest course of action from a WX perspective.
1.3
The task of collecting weather data is delegated to a dispatcher or other ground personnel.
Essential information like Frontal systems, low and high pressure systems are not depicted in current
SIGWX charts. Showing only CB's and omitting all other cloud types may lead to wrong assumptions by
pilots.
2.
TEXT PRIOR TO LATEST
ANNEX 3 PART II APPENDIX 4
AMENDMENT
ICAO
4.3 Specifications related to significant weather information
4.3.1 In chart form
4.3.1.1 Where information on significant en-route weather phenomena is supplied in chart form to flight
crew members before departure, the charts shall be significant weather charts valid for a specified fixed
time. Such charts shall show, as appropriate to the flight:
a) thunderstorms;
b) tropical cyclone;
c) severe squall lines;
d) moderate or severe turbulence (in cloud or clear air);
e) moderate or severe icing
f) widespread sandstorm/duststorm;
g) for flight level 100 to flight level 250, clouds associated with a) to f);
h) above flight level 250, cumulonimbus cloud associated with a) to f);
i) surface position of well-defined convergence zones;
j) surface positions, speed and direction of movement of frontal systems when associated with significant
enroute weather phenomena
k) tropopause heights;
l) jetstreams
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WAFSOPSG/5-IP/8
m) information on the location of volcanic eruptions which are producing ash clouds of significance to
aircraft operations, including those producing only steam, comprising; volcanic eruption symbol at the
location of the volcano and, at the side of the chart, the volcano eruption symbol, the name of the
volcano, its international number, latitude/longitude, the date and time of first eruption, if known, and a
reference to SIGMETs and NOTAM or ASHTAM issued for the area concerned; and
n) information on the location of an accidental release of radioactive materials into the atmosphere of
significance to aircraft operations, comprising: the radioactivity symbol at the site of the accident and, at
the side of the chart, the radioactivity symbol, latitude/longitude of the site of the accident, date and time
of the accident and a reminder to users to check NOTAM for the area concerned.
3.
ICAO ANNEX 3, PART II, APPENDIX 2 CHAPTER 1
ICAO ANNEX 3, INCLUDING AMENDMENT 74
NOVEMBER 2007
3.1
ICAO para. 1.3.3 states that High-level and medium-level SIGWX forecasts shall include
the following items:
a) tropical cyclone provided that the maximum of the 10-minute mean surface wind speed is expected to
reach or exceed 63 km/h (34 kt);
b) severe squall lines;
c) moderate or severe turbulence (in cloud or clear air);
d) moderate or severe icing;
e) widespread sandstorm/duststorm;
f) cumulonimbus clouds associated with thunderstorms and with a) to e)
Note. ― Non-convective cloud areas associated with in-cloud moderate or severe turbulence
and/or moderate or severe icing are to be included in the SIGWX forecasts.
g) flight level of tropopause;
h) jet streams;
i) information on the location of volcanic eruptions that are producing ash clouds of significance to
aircraft operations comprising: volcanic eruption symbol at the location of the volcano and, at the side of
the chart, the volcano eruption symbol, the name of the volcano, latitude/longitude, the date and time of
first eruption, if known, and a reference to SIGMET and NOTAM or ASHTAM issued for the area
concerned; and
j) information on the location of an accidental release of radioactive materials into the atmosphere, of
significance to aircraft operations, comprising: the radioactivity symbol at the site of the accident and, at
the side of the chart, the radioactivity symbol, latitude/longitude of the site of the accident, date and time
of the accident and a reminder to users to check NOTAM for the area concerned.
Note ―. Items to be included in low-level SIGWX forecasts (i.e. flight levels below 100) are
included in Appendix 5.
WAFSOPSG/5-IP/8
4.
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CONSIDERATIONS
4.1
Safety Issue: Information in picture about frontal systems is a safety issue. Short term
cost savings will be offset by loss of human lives on the long run, increasing costs for the airline
concerned. Short-sighted cutting of vital data increases the risk of a total loss of an aircraft significantly.
Weather is basic to flying, weather affects the success of the operation. Weather is a major contributing if
not causal factor in almost all landing and approach accidents and while the investigation of AF 446 is
ongoing it is clear that weather was a contributing factor.
4.2
Situational Awareness: There is a big difference between looking at a map with some
delineated areas containing cloud types (say an area size of half of Europe with the indication of
occasional Cb) and looking at a map showing the cause for the weather phenomena. The mere presence of
a frontal system at the destination will alert the pilot and increase his situational awareness drastically.
4.3
Meteorological Basics: flight crews go through meteo-courses and learn to interpret the
information on the weather maps. Omitting exactly the core-content of weather maps (i.e. the frontal
systems) is counterproductive since no matter how accurate, predictions are only predictions. Pilots can
identify actual phenomena and relate them to frontal systems and thus compare the predictions to actual
conditions in order to form a mental picture whether a Front and its associated weather is moving
faster/slower than expected and how that will affect the safety of the operation.
4.4
Purpose of the Chart: The purpose of the chart is updating flight crews about all aspects
of weather at the point of departure up to the destination and alternate aerodrome. With the present maps
this is not possible.
4.5
Future Developments: A mayor concern is that by dropping Frontal systems from
SIGWX charts in Annex 3 they are no longer being considered on any new developments as can clearly
be seen on the recent development of the Gridded Forecast project. Thus a further concern to keep frontal
systems depicted on SIGWX Charts.
5.
DISCUSSION
5.1
IFALPA believes that the elimination of surface fronts, convergence zones and clouds
other than CB from the high and medium level SIGWX forecasts is detrimental to safety and situational
awareness of flight operations.
5.2
Therefore surface fronts, convergence zones and clouds including CB from the high and
medium level SIGWX forecasts need to be depicted in chart form and made available to flight crews.
5.3
Based on the above ; Specifications related to significant weather information in chart
form shall be reinstated to what it was prior to amendment 74.
6.
6.1
ACTION BY THE WAFSOPSG
The WAFSOPSG is invited to note the information contained in this paper.
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