Visible flag, yes, but a distraction could keep you from looking under the wing.

By Steven DeGroff

Preflight inspections have to cover a lot of bases, but there is one class of accidents that illustrate how some pilots apparently don’t conduct even the most superficial of walk-arounds.

A study of the NTSB accident database revealed 40 accidents over a 19-year period in which the pitot tube or another component of the pitot system was listed as a probable cause of the accident. In another 122 accidents accident investigators suspected the pitot system shared some of the blame. Since incidents are typically not included in the database, an unknown number of incidents also happened in that period. In addition, a number of pilots probably smoked their…