PREFLIGHT WEATHER ANALYSIS CHECKLISTS - VFR FLIGHT
(Ed. Note: Apologies to my source, which on this occasion I failed to record! However, the advice received below should be taken on board by all!)
Ceiling and Visibility
· How much airspace do I have between the reported or forecast ceilings and the terrain along my route of flight? Does this information suggest any need to change my planned altitude?
· If I have to fly lower to remain clear of clouds, will terrain be a factor?
· How much ground clearance will I have?
· Do I have reliable ceiling information?
· Will I be over mountainous terrain or near large bodies of water where the weather can change rapidly, or where there may not be a nearby weather reporting station?
· What visibility can I expect for each phase of flight? (take-off, en-route, landing)
· Given the speed of the aircraft, expected light conditions, terrain, and ceilings, are the reported and forecast visibility conditions sufficient for this trip?
· Are there conditions that could reduce visibility during the planned flight?
· (Hint: look for indications such as a small and/or decreasing temperature & dew point spread).
· Are reported and forecast ceiling & visibility values above my personal minimums?
· Given temperature, altitude, density altitude, and aircraft loading, what is the expected aircraft performance in respect of?
· Take-off distance
· Time & distance to climb
· Cruise performance
· Landing distance
· Are these performance values sufficient for the runways to be used and the terrain to be crossed on this flight?
*(Note:Remember that it is always good practice to add a 50% to 100% safety margin to the “book Numbers” you derive from the charts in the aircraft’s approved flight manual (AFM)
· Are the wind conditions at the departure and destination airports within the gust and crosswind capabilities of both pilot and aircraft?
* (Note: For most GA pilots, personal minimums in this category might be for a maximum gust of 5 knots and maximum crosswind component 5 knots below the maximum demonstrated crosswind component.)
· What is the manoeuvring speed (VA) for this aircraft at the expected weight?
*(Note: Remember that VA is lower if you are flying at less than maximum gross weight.)