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WAFSOPSG/5-IP/8/ 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 businessDEPICTION OF FRONTAL SYSTEMS OF SIGWX CHARTS
(Presented by IFALPA)
SUMMARYInformation 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.
1.INTRODUCTION
1.1With 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.
1.2Frontal 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.
1.3The 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 AMENDMENT ICAO ANNEX3 PART II APPENDIX 4
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
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
3.1ICAO 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.
4.CONSIDERATIONS
4.1Safety 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.
4.2Situational 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.
4.3Meteorological 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.
4.4Purpose 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.
4.5Future 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 developmentsas 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
5.1IFALPA 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.
5.2Therefore 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.
5.3Based on the above ; Specifications related to significant weather information in chart form shall be reinstated to what it was prior to amendment 74.
6.ACTION BY THE WAFSOPSG
6.1The WAFSOPSG is invited to note the information contained in this paper.
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