Approach Planning  Weather Considerations  Depending on speed of the aircraft, availability of weather  information, and the complexity of the approach procedure  or special terrain avoidance procedures for the airport  of intended landing, the in-flight planning phase of an  instrument approach can begin as far as 100-200 NM from  the destination. Some of the approach planning should  be accomplished during preflight. In general, there are  five steps that most operators incorporate into their flight  standards manuals for the in-flight planning phase of an  instrument approach:  Although often modified to suit each individual operator,  these five steps form the basic framework for the in-flight  planning phase of an instrument approach. The extent of  detail that a given operator includes in their SOPs varies  from one operator to another; some may designate which  pilot performs each of the above actions, the sequence, and  the manner in which each action is performed. Others may  leave much of the detail up to individual flight crews and  only designate which tasks should be performed prior to  commencing an approach. Flight crews of all levels, from  single-pilot to multi-crewmember Part 91 operators, can  benefit from the experience of commercial operators in  developing techniques to fly standard instrument approach  procedures (SIAPs).  Determining the suitability of a specific IAP can be a very  complex task, since there are many factors that can limit  the usability of a particular approach. There are several  questions that pilots need to answer during preflight  planning and prior to commencing an approach. Is the  approach procedure authorized for the company, if Part  91, subpart K, 121, 125, or 135? Is the weather appropriate  for the approach? Is the aircraft currently at a weight that  will allow it the necessary performance for the approach  and landing or go around/ missed approach? Is the aircraft  properly equipped for the approach? Is the flight crew  qualified and current for the approach? Many of these types  of issues must be considered during preflight planning and  Air carriers and operators certificated under the provisions  of Part 119 (Certification: Air Carriers and Commercial  Operators) are required to use the aeronautical weather  information systems defined in the OpSpecs issued to that  certificate holder by the FAA. These systems may use basic  FAA/National Weather Service (NWS) weather services,  contractor or operator-proprietary weather services, and/  Most of the weather information that flight crews receive  is issued to them prior to the start of each flight segment,  but the weather used for in-flight planning and execution  of an instrument approach is normally obtained en route  via government sources, company frequency, or Aircraft  Communications Addressing and Reporting System  (ACARS).  Windspeed and direction are factors because they often  limit the type of approach that can be flown at a specific  location. This typically is not a factor at airports with  multiple precision approaches, but at airports with only a  few or one approach procedure, the wrong combination  of wind and visibility can make all instrument approaches  at an airport unavailable. Pilots must be prepared to  execute other available approaches, not just the one that  they may have planned for. As an example, consider the  available approaches at the Chippewa Valley Regional  Airport (KEAU) in Eau Claire, Wisconsin. [Figure 4-1] In the  event that the visibility is reported as less than one mile,  the only useable approaches for Category C aircraft is the  Instrument Landing System (ILS) and Lateral navigation  (LNAV)/vertical navigation (VNAV) to Runway 22. This  leaves very few options for flight crews if the wind does not  favor Runway 22; and, in cases where the wind restricts a  landing on that runway altogether, even a circling approach  cannot be flown because of the visibility.  Weather conditions at the field of intended landing dictate  whether flight crews need to plan for an instrument  approach and, in many cases, determine which approaches  can be used, or if an approach can even be attempted. The  gathering of weather information should be one of the first  steps taken during the approach-planning phase. Although  there are many possible types of weather information,  the primary concerns for approach decision-making are  windspeed, wind direction, ceiling, visibility, altimeter  setting, temperature, and field conditions. It is also a good  idea to check NOTAMs at this time, in case there were any  changes since preflight planning.  within the framework of each specific air carrier’s OpSpecs,  or Part 91.  Weather Sources  • Gathering weather information, field conditions,  and Notices to Airmen (NOTAMs) for the airport of  intended landing.  • Calculation of performance data, approach speeds,  and thrust/power settings.  • Flight deck navigation/communication and  automation setup.  • Instrument approach procedure (IAP) review and, for  flight crews, IAP briefing.  • Operational review and, for flight crews, operational  briefing.  4-2 