Jan. 28, 2019
Online aviation weather resources can help schedulers and dispatchers plan trips.
There are several things that schedulers and dispatchers can do to prepare and execute a flight that will make life easier for everyone involved and possibly even limit delays.
First, remember that by helping ATC, you are really helping yourself. You can do this by following the three simple steps on the FileSmart web page (filesmart.org) – file flight plans early, file them accurately and check the status of the National Airspace System (NAS).
Filing flight plans as early as possible provides the FAA with an accurate picture of expected demand and can help reduce delays that arise as a result of constraints in the NAS. The more “known demand” that air traffic managers can see ahead of time, the easier it is for them to make timely and accurate decisions regarding traffic management initiatives (TMIs).
Next, file an accurate flight plan. The days of filing Teterboro to San Francisco direct are gone. The FAA suggests that you use the International Civil Aviation Organization flight plan format in order to give ATC the most detailed information regarding what types of SIDs, STARs or en-route procedures your aircraft and crew can fly.
Finally, “check the status of the NAS” means making yourself familiar with the following three weather resources so you understand how weather impacts deci-sions made by ATC regarding TMIs.
1) The National Weather Service’s (NWS) Weather Prediction Center (WPC)
The WPC “fronts” tab shows weather fronts and pressure systems up to seven days in advance. However, the really valuable part of this resource is the 48-hour outlook. In addition to seeing the locations of the pressure centers and the fronts, you see all the types of precipitation expected during that period. The legend in the lower left corner identifies the different types of precip. This product gives you a broad-based look at several snapshots in time, which gives you a general idea of what to expect. This is useful because precipitation has the potential to bring low ceilings and reduced visibility, two things that can have a significant impact on terminal operations.
2) The Traffic Flow Management (TFM) Convective Forecast (TCF)
This is the result of decades of collaborative work between the NWS, FAA and industry (including NBAA) to develop a better convective-weather decision-making tool for air traffic managers. This tool has evolved from painting large areas of possible (low confidence) thunderstorm activity to much more focused areas of only high-confidence convective activity. These projections answer four questions for air traffic managers: When are storms expected? Where are the storms expected? How high will these storms reach? How permeable will these areas of weather be?
3) The Graphical Forecast for Aviation (GFA)
This new resource actually consists of several products that can help you identify areas that might lead to TMIs. There are several great things about the GFA, not the least of which is the ability to look out 15 hours into the future and zoom in anywhere on the map, thus making it easier to obtain more weather detail than via old text-based area forecasts. On several panels, you’ll also notice an additional slide along the left side, which adds the ability to look at different altitudes in addition to different times.
Three GFA panels are particularly pertinent when it comes to how traffic managers will deal with weather.
The Turbulence Panel
Turbulence is more of an issue in the en-route environment. Shown here is one of the panels that has the altitude slider on the left, enabling users to find smooth air by showing the areas of turbulence at each altitude band (in this case, FL360 includes the airspace from FL330 to FL390). This chart also shows the AIRMET and SIGMET weather advisories, which depict large areas that pilots might want to avoid. In order to facilitate moving aircraft out of these areas in an orderly fashion, traffic managers look at this information in advance and may decide to issue required reroutes.
The Icing Panel
Again, the left-hand slider enables users to look at different levels of the atmosphere. In this case, we’re interested in the lower altitudes (from 3,000 to 12,000 feet), where we might see aircraft holding as they get closer to their destination. To keep crews from having to hold in areas of icing near a terminal, traffic managers may use ground delay programs or ground stops to manage the amount of traffic arriving in that airspace during the time of expected icing conditions.
The Winds Panel
In this example, the altitude slider on the left shows the winds from the surface to about 6,000 feet. In some cases, when you look at the surface level, you may see “LLWS,” which indicates that low-level wind shear is possible. Something else to check is the difference in wind speeds with elevation. If there is a large difference between winds at the surface and those at 3,000 feet, ATC can have issues with what they call “compression.” Under these conditions, aircraft will have very high ground-speeds on their downwind leg, but they will slow down substantially once they turn final. This requires significant extra spacing on final approach (which they don’t have a lot of in places like the New York metro area). Again, air traffic managers will occasionally use ground delay programs to slow traffic down as a result.