Two Nine Nine Two at Fifteen

     The most dangerous aspect of weather is not any one violent or extreme phenomena. Certainly, wind, wind shear, and sudden gusts are well documented as the leading causes of weather-related accidents (AOPA, 2020). This is not a matter of opinion. But violent storms and unpredictable winds are not the most dangerous trick weather can play on the aviator. What is this dangerous phenomenon that everyone who takes to the skies must deal with, from the student to the 30 year veteran?

Not this, surprisingly.

     A search of all NTSB crash investigations shows that 57601 accidents occurred in Visual Meteorological Conditions (VMC) while 4948 occurred in Instrument Meteorological Conditions (IMC) (NTSB, 2020). In 2018 there was 23 non-commercial fixed-wing accidents out of a total of 1033 accidents categorized as weather type (AOPA, 2020). Since 2009 there has not been more than 65 weather related accidents in the non-commercial fixed-wing category (AOPA, 2020). Most of these accidents are caused by flying from Visual Flight Rules (VFR) into IMC conditions (AOPA, 2020). Day VMC accidents make up nearly 40% of weather-related accidents, more than any other condition (AOPA, 2020).

     Why are these numbers not higher? There are many dangerous weather conditions which directly contribute to aviation accidents. Given that only 32 out of 1033 accidents in 2018 are directly weather related and nearly half start in VMC conditions leads to one conclusion (AOPA, 2020).

    The most dangerous weather condition is “a great day to fly.” A  sunny day, with light, consistent winds and unlimited visibility can cause a sense of security. If you have ever been a passenger on an airplane you probably know that a thunderstorm will wake you up. Generally, the extra threat of adverse weather increases awareness and attention, keeping the pilot and crew looking for weather related problems as well as other concerns. The pilot is far more cautious when maneuvering the airplane and tightens up in flight discipline.

    But on a sunny day, when there is not much to worry about it can be easy to become complacent. For anyone with a good amount of experience in something as complicated as flying an airplane, many of the sequences involved can become second nature. This coupled with a lowered awareness brought about by a nice day may lead to a pilot not noticing missing steps or problems with the aircraft. Adverse weather can also contribute to forcing a crew to slow down and consider more carefully risks involved.

Nall Report Figure View. AOPA. (2020, July 21). https://www.aopa.org/training-and-safety/air-safety-institute/accident-analysis/joseph-t-nall-report/nall-report-figure-view?category=all&year=2018&condition=all&report=true.

NTSB Aviation Accident Database & Synopses. National Transportation Safety Board (NTSB). https://www.ntsb.gov/_layouts/ntsb.aviation/index.aspx.