1. © Crown copyright Met Office Use of GRIB hazard forecasts in flight planning Bob Lunnon, Aviation Outcomes Manager, Met Office WAFS Science meeting, Washington, April 20th 2009

2. © Crown copyright Met Office Introductory comment To some, this approach to using the GRIB hazard products might seem obvious However, there needs to be very effective dialogue between the various stakeholders (including WAFCs, flight planning companies, airlines, regulators) for cost-effective use of the products to be possible We have an opportunity to ensure that all concerned collaborate to ensure optimum use of the products

3. © Crown copyright Met Office Use forecast of CAT as an example for other hazards We have more experience in forecasting CAT than other hazards, and in verifying our forecasts We have estimates of the cost of a CAT encounter We have done calculations on the total cost of a flight, including cost of CAT encounters Approach can be extended to other hazards (Cb, icing) if costs are known

4. © Crown copyright Met Office Flying from A to B through area of forecast high frequency of CAT A B Black in centre of plot indicates area of high frequency of CAT Dark grey in plot indicates area of moderate frequency of CAT Light grey in plot indicates area of low frequency of CAT This graphic could be either a map or a cross-section (later we will assume it is a map)

5. © Crown copyright Met Office Possible strategies for avoiding areas where forecast CAT is above some threshold A B Can in principle choose routes which tangentially touch areas where CAT frequency is above some threshold (with Met Office optimum route system can do this)

6. © Crown copyright Met Office Most flight planning systems consider a network of fixed routes A B Here we show only routes which realistically might be chosen when flying from A to B (Network of routes may be different scale to CAT areas)

7. © Crown copyright Met Office Consider direct route from A to B Graph at bottom of plot indicates expected frequency of CAT as aircraft flies directly from A to B A B

8. © Crown copyright Met Office Consider route chosen to maximise CAT avoidance Graph at bottom of plot indicates expected frequency of CAT as aircraft flies from A to B along indicated route

9. © Crown copyright Met Office Compare routes Information in graphs should be generated by flight planning companies and fed to airlines/pilots

10. © Crown copyright Met Office Costs of CAT encounters and CAT avoidance If fly round light grey area, cost of CAT encounters is low, cost of CAT avoidance is high If fly round black area, cost of CAT encounters is high, cost of CAT avoidance is low It should be possible to identify CAT avoidance strategy which minimises total cost

11. © Crown copyright Met Office CAT avoidance Note that a very limited number of flights were used to generate this figure

12. © Crown copyright Met Office Information needed to generate cost-benefit graph Information on extra distance flown for each avoidance strategy (from flight planning company) Information on cost of extra distance flown (from airlines) Information on frequency of actual CAT encounters for each avoidance strategy (from WAFC)(depends on accuracy of forecasts) Information on cost of CAT encounters (from airlines)

13. © Crown copyright Met Office Figures used to generate cost-benefit graph Study undertaken in 1990s Used Met Office Optimum route package to calculate extra distance flown, and extra time to fly additional distance Used then price of fuel to derive a cost Used verification statistics to derive frequency of CAT encounters Used figures from Tom Fahey for cost of CAT encounter Avoiding areas of high (>6%) CAT probability was financially better than no CAT avoidance Our forecasts have improved since then!

14. © Crown copyright Met Office Use of hazard data in airline flight planning systems For any route under consideration calculate time to fly, conventional cost, fuel, as at present For any route, calculate average forecast CAT frequency Using data from WAFC, calculate expected frequency of CAT encounters for all prospective routes Derive cost of CAT encounters for all prospective routes

15. © Crown copyright Met Office Optimum routes westbound for 10/12/2008, from 5/12/2008

16. © Crown copyright Met Office Questions & answers