Just some lists of things that increase the probability of an aircraft accident.
Experts have probably calculated exact risk ratios for these different, well-established factors:
- Improper maintenance
- Extension of maintenance intervals beyond manufacturer recommendations
- Opting to defer replacement of noticeably worn parts
- Not following manufacturer repair instructions
- Part substitution (using parts that differ slightly from official specifications)
- Bad weather (ice, convective storms)
- Limited visibility (night, fog)
- Human error
- Assuming increased risk due to desire to be at destination
- Improper use of checklists (checking items before they are performed)
- Skipping “rote” checks and safeguards because they rarely reveal issues
- Changing plans mid-flight (increases cognitive burden while plane is in motion)
- Miscommunication (language barrier, being overly deferential to captain or traffic control)
- Lax safety culture
- Inadequate classroom instruction
- Skipping of double-checking (when warranted) by second individual or supervisor
- Airport infrastructure issues
- Inadequate regulation of construction
- Inadequate de-icing
- Computers
- Burdensome number of (or contradictory) errors reported to pilots
- Too many sensor malfunctions (distrust of computer-reported errors)
If I had to add to this list with a few guesses of my own, I’d add that these are likely factors:
- Fatigue
- Regulatory capture of governmental regulatory bodies by operators (e.g., easy approval of maintenance interval extensions, too-friendly relationships)
- Social and career consequences of whistle-blowing
- Corporate cultures that reward metrics that are at-odds with safety (operators, airports, airplane manufacturers, etc.)
And there are some hypothetical, debated factors as well:
- Complexity