How often do pilots skip checklist steps?

Board blames fatal overrun on pilot error.
Source: NTSB Issues Bedford Gulfstream IV Crash Report | Flying Magazine

Checklists were a major innovation in flying, and are now being pushed in health care. But as I research this, it’s clear that although pilots all swear by them, use is less than 100%. Perhaps less than 99% – and a 1% error rate is very high when there are hundreds of items on a flight.

It’s very hard to know the real number. But the pilots in this crash, both very experienced, did pre-takeoff control checks for less than 10% of their flights!

Data from a recorder installed in the airplane showed that in the previous 176 takeoffs, full flight control checks as called for on the GIV’s checklist were carried out only twice and partial checks only 16 times. The pilots on the evening of the accident skipped the flight control check, which might have revealed to them that the gust lock mechanism was still engaged.

This particular item – forgetting to unlock the “gust locks” – has been killing pilots since the first gust locks. Famous examples in the 1930s were the prototype B-17, and the head of the German Air Force. (Both discussed in my forthcoming chapter on standard procedures in aviation.)
Gulfstream IV jet with six on board - crashed and burned after failed takeoff.


This is the “entry page” for my paper on the slow adoption of better flying methods in WW 2. Please link to this page, rather than to the actual PDF, which I will be updating.  Here is the paper itself. (July 19 version)

In the late 1930s, US military aviators in the American Army and Navy began using aviation checklists. Checklist became part of a new paradigm for how to fly, which I call Standard Procedure Flying, colloquially known as “flying by the book.” It consisted of elaborate standardized procedures for many activities, checklists to ensure they key steps had been done, and quantitative tables and formulas that specified the best settings, under different conditions, for speed, engine RPM, gasoline/air mixture, engine cooling, and many other parameters. This new paradigm had a major influence on reducing aviation accidents and increasing military effectiveness during World War II, particularly because of the rapidly increasing complexity of military aircraft, and the huge number of new pilots. Continue reading