Which single line checklist items, when missed, could lead to a crash?

[MountainDude]

I can start with:
- forget to remove control lock
- leave the trim set for landing before take-off
- not pushing mixture rich before takeoff at sea level if you taxi with very lean mixture
- in a Cessna, not putting the fuel selector to "both"

 

[TonyG]

My old man was a career fighter pilot, and he cautioned me about falling too far down the "checklist mentality" rabbit hole. Not that he (or I) thought checklists were bad - they're great and essential when used properly. But if you don't pay attention to what's really important (in addition to using the checklist), you'll be at risk of bringing the "always cause a crash" items to the same level as making sure your transponder's on.

So: I'd change your list title to "Which single line checklist items, when missed, WILL lead to a crash?" I can think of one: GEAR HANDLE DOWN. That will result in a crash every single time (in retracts, of course).

The control lock may be right there too, but that'd be missing an item about 4 times in preflight and runup. Your other items are in the "could" category.

 

[wanttaja]

None, in my airplane. Forgetting to activate the carb heat before pulling power may result in carb icing, but I generally don't pull the power until the runway is made.

Ron Wanttaja

 

[Initial Fix]

Gear down
Seat secure

preflight- check cowl latched

 

[AV8R_87]

In any airplane, not ensuring the fuel selector is in the on position (whatever version of on is available for that plane).
I recall a Cessna 150 checklist that had you ckeck it three times before takeoff (pre-flight, engine start and run-up).