Ch 17 – Weather Evaluation for Flight

Ch 17 – Weather Evaluation for Flight Introduction A fact of aviation today is that you must have a better understanding of weather than your predecessors There are at least two primary reasons for this. First, approximately 25% of aircraft accidents are weather-related A weather-wise pilot is much less likely to become a statistic

Ch 17 – Weather Evaluation for Flight Second, the rapid growth in the aviation industry and the increasing automation of weather information places a greater burden on you to obtain and interpret weather information pertinent to your flight

Ch 17 – Weather Evaluation for Flight The concept of a “self-briefing” to augment official briefings requires that you develop a procedure to obtain and integrate weather observations and forecasts into your preflight preparations This chapter provides guidelines to help you develop a self-briefing procedure That procedure is then demonstrated by applying it to an actual weather situation

Ch 17 – Weather Evaluation for Flight Finally, an outlook for improvements in aviation weather observations, forecasts, products, and information delivery is also provided. When you complete Chapter 17 you will understand the process of combining a variety of weather information via an effective self-briefing procedure

Ch 17 – Weather Evaluation for Flight You will also be aware of important future developments that will lead to significant improvements in your operational application of aviation weather knowledge and in-flight safety

Ch 17 – Weather Evaluation for Flight Section A – Self – Briefing Procedure Self Evaluation Aircraft Capability Flight Description

Ch 17 – Weather Evaluation for Flight Section B – Weather – Evaluation Process Overview Preflight Evaluation In-Flight Evaluation

Ch 17 – Weather Evaluation for Flight Section C – Developments in Aviation Weather Resources Observation Systems Weather Forecasting Weather Information Systems

Ch 17 – Weather Evaluation for Flight Section A: Self – Briefing Procedure To improve your proficiency in weather evaluation, the development of a system for processing information during flight planning is valuable

Ch 17 – Weather Evaluation for Flight A flow diagram outlining this process is shown in figure 17-1 Weather Awareness Knowledge of available and relevant weather products Self evaluation Aircraft Capability

Ch 17 – Weather Evaluation for Flight Flight description Weather Overview Preflight Weather Evaluation (cancel, go, delay) In-flight Weather Evaluation No change – proceed to destination Divert – Alternate

Ch 17 – Weather Evaluation for Flight Is your meteorological training adequate? Are you familiar with relevant weather products and their sources?

Ch 17 – Weather Evaluation for Flight Self Evaluation Are you current to flying in the weather conditions of the proposed flight? Is your weather knowledge current Are you up-to-date on the latest weather resources?

Ch 17 – Weather Evaluation for Flight Aircraft Capability A complete understanding of your aircraft’s performance capability and limitations is essential in evaluating the weather’s impact The equipment onboard your aircraft is another factor to consider when assessing aircraft capabilities Based on a complete assessment of yourself and your aircraft you can set specific weather restrictions for your flights

Ch 17 – Weather Evaluation for Flight Flight Description The next step in the self-briefing process is to establish a complete flight description Figure 17-2; a flight plan form can be used as a reference for the flight description items supplied to a briefer

Ch 17 – Weather Evaluation for Flight ***When you request a briefing, identify yourself as a pilot and supply the briefer with the following information: type of flight planned (VFR or IFR) aircraft number or pilot’s name aircraft type

Ch 17 – Weather Evaluation for Flight departure airport route of flight Destination flight altitude(s) estimated time of departure and estimated time en-route or estimated time of arrival

Ch 17 – Weather Evaluation for Flight Section B: Weather Evaluation Process Once the initial steps of the self-briefing procedure are complete, the analysis of weather for a specific flight can begin Your misinterpretation of a critical piece of weather information is a pilot error

Ch 17 – Weather Evaluation for Flight Misinterpretations of weather observations and forecasts are usually due to not knowing one or more of the following: What is available What the information means Where you can get it When it is available

Ch 17 – Weather Evaluation for Flight Overview It is worthwhile to begin assessing the general weather situation a day or two before the flight Pay attention to weather reports and forecasts on radio and television As time goes on, details should be added to the general patterns The Internet or an FSS outlook briefing is helpful at this point

Ch 17 – Weather Evaluation for Flight About 24 hours in advance of your departure, ask yourself these questions: Where are the areas of potentially adverse weather currently located? How have those areas been moving/developing in the last 24 hours or so? Where will those areas be at the time of your flight?

Ch 17 – Weather Evaluation for Flight What are the specific flight hazards? Refer to the surface analysis charts In many weather situations, the intensity and organization of the weather system becomes clearer when you examine upper air conditions Refer to constant pressure analysis charts

Ch 17 – Weather Evaluation for Flight Refer to low-level significant weather prognostic charts Your efficient use of weather information requires that you determine all of the weather hazards significant to your flight An outlook briefing from flight service furnishes additional information at this stage

Ch 17 – Weather Evaluation for Flight Preflight Evaluation The preflight weather evaluation is usually accomplished within a few hours of the proposed departure time due to the importance of procuring the latest information prior to the flight Graphic weather material makes it much easier and faster to visualize the weather situation

Ch 17 – Weather Evaluation for Flight This includes satellite images and maps of various weather phenomena Plotted in-flight weather advisories and maps showing recent PIREPs are particularly useful

Ch 17 – Weather Evaluation for Flight One of your important tasks at this stage is to make use of all advisories or warnings issued for the area at the time of your flight; look at area forecast, AIRMETS - Sierra, Tango, Zulu, SIGMETS, CONVECTIVE SIGMETS, surface analysis charts, weather depiction charts To conclude the weather evaluation, you must make a decision based on your analysis An important component of the self-briefing procedure is your own weather observation

Ch 17 – Weather Evaluation for Flight In-Flight Evaluation Your evaluation of the weather does not end if a go decision is made The dynamic nature of weather makes in-flight weather evaluation essential to safety

Ch 17 – Weather Evaluation for Flight While en-route you should also use in-flight weather services such as recorded surface observations and forecasts (TWEB, HIWAS) Figure 17-16; Flight Watch is a valuable weather service provided by flight service stations

Ch 17 – Weather Evaluation for Flight Section C: Developments in Aviation Weather Resources The worldwide aviation community is making major changes in the way weather data are gathered, processed and disseminated In the US, the FAA and the National Weather Service are implementing plans leading to an advanced and improved aviation weather system

Ch 17 – Weather Evaluation for Flight This system will integrate present and pending technologies to develop higher resolution and more accurate observations of atmospheric variables Increased computer power and modeling capabilities will significantly enhance weather analyses and forecasts Weather information will be transformed into aviation decision aids based on weather variables impacting flight

Ch 17 – Weather Evaluation for Flight Observation Systems The focus of modernized weather observation is the production of high-quality data in nearly real time It is expected that there will be 1,500 automated surface-observation stations such as ASOS and AWOS

Ch 17 – Weather Evaluation for Flight The Doppler weather radar (WSR-88D) was deployed initially as NEXRAD and is now the primary tool of the US weather radar network Terminal Doppler weather radar (TDWR) has been installed at numerous large airports in the US where thunderstorms and microbursts are most common

Ch 17 – Weather Evaluation for Flight Low-level wind shear alert systems (LLWAS) have been installed at 110 airports in the US The radiosonde network has been the primary upper-air data source for weather forecasting for many years The wind profiler is a vertically pointing microwave radar that measures horizontal wind speed and direction at 72 levels between about 1,500 feet AGL and 53,000 feet MSL

Ch 17 – Weather Evaluation for Flight Another on-going development in upper-air observations has been the development of the international aircraft meteorological data reporting (AMDAR) system using commercial aircraft as observational platforms There are two primary data-gathering systems by AMDAR The first is the aircraft-to-satellite data relay (ASDAR) system which uses specially designed hardware that must be fitted to and certified for the aircraft on which it is installed

Ch 17 – Weather Evaluation for Flight The second method for the gathering of meteorological information from aircraft is the aircraft communications, addressing and reporting system (ACARS) The AMDAR (ASDAR/ACARS) system has been highly successful

Ch 17 – Weather Evaluation for Flight The modern weather satellite has developed far beyond the acquisition of images of cloud patterns Satellites such as the geostationary operational environmental satellite (GOES) provide simultaneous imaging as well as temperature and moisture profiles

Ch 17 – Weather Evaluation for Flight Weather Forecasting In addition to more and better meteorological observations, a better understanding of atmospheric processes, faster computers, and better numerical techniques are leading to significant improvements in weather forecasting A strong US government initiative in support of aviation has resulted in the development of the aviation gridded forecast system (AGFS)

Ch 17 – Weather Evaluation for Flight The purpose of AGFS is to use the output from NCEP models, such as RUC and other specialized computer code to generate high resolution Aviation Impact Variables (AIV) The Aviation Division of the NOAA Forecast Systems Laboratory works cooperatively with the Aviation Weather Center (AWC) to integrate AIVs into the aviation forecast process

Ch 17 – Weather Evaluation for Flight Other on-going efforts to improve aviation weather forecasts are aimed at thunderstorms, ceiling and visibility predictions, ground deicing, and the prediction of wake vortex behavior at air terminals

Ch 17 – Weather Evaluation for Flight Weather Information Systems Effective aviation weather information systems must meet two important requirements The world area forecast system (WAFS) is a satellite communications system to provide the worldwide aviation community with weather information for flight planning and to support the en-route phase of flight

Ch 17 – Weather Evaluation for Flight In the US, the FAA’s Aviation Weather Research (AWR) program supports a research project that is addressing the need for improved weather presentation Two other significant components of the AWR program are the aviation weather products generator (AWPG) and the integrated terminal weather system (ITWS)

Ch 17 – Weather Evaluation for Flight The purpose of the AWPG is to provide analysis and forecast products tailored for the en-route phase of flight ITWS is designed to enhance the FAA’s ability to monitor and predict weather that impacts aircraft in the vicinity of the terminal

Ch 17 – Weather Evaluation for Flight Input into ITWS includes LLWAS, weather radar, automated weather observations, aircraft observations and forecast model output By 1999, ITWS had been deployed to 34 locations serving 45 of the busiest airports in the US

Ch 17 – Weather Evaluation for Flight In the future, the weather requirements for free flight and other planned improvements to the national and global air navigation systems will make rapid delivery of better weather information to the cockpit a priority Beyond TWIP, the FAA is developing standards and procedures for the transmission of enhanced weather information directly to the cockpits of aircraft in all phases of flight

Ch 17 – Weather Evaluation for Flight As these cockpit request/display systems become a reality, concern for simplicity in operation and interpretation will be critical in order to reap the maximum safety benefits in an already busy cockpit

Ch 17 – Weather Evaluation for Flight Summary The future holds exciting advancements in aviation weather technology including improved observations and forecasts, and better access to weather products that are more comprehensive, yet easier to interpret

Ch 17 – Weather Evaluation for Flight In order to make the best use of these developments for safe and enjoyable flying, you must continually make an effort to stay abreast of new systems and weather products as they become operational.

Ch 17 – Weather Evaluation for Flight Your meteorology education has only started here It is a continuing process As with flying, it is up to you to stay current with aviation weather