Every CFI I've ever had made me use a paper checklist for everything from the pre-flight to taxiing back to the ramp.
That's great if you have a multi-pilot crew... Not so good in some situations if you're the only pilot aboard.
GUMPS is a acronym, not a checklist, genius.
It's an acronym for a checklist. You must really enjoy picking nits.
Especially since it allows a pilot to use a pre-landing checklist as they should, while keeping their eyes outside which they also should (as you stated).
A checklist is something in front of you that you check off.
If you want to get so technical - I've never seen anyone actually check anything off, since they'd have to make a new copy of the checklist for each flight/use.
So, I'd say that for the purposes of flying, a "checklist" is something that allows the pilot to ensure that all pertinent actions have been completed for a particular phase of flight.
Since your memory isn't in front of you it isn't a checklist, just a series of memorized items which you may or may not miss.
There are memory techniques that allow a checklist as defined above to be something memorized.
I use several different types of checklists:
1) Paper. Good for when you are able to look inside the plane without risk, such as for an After Landing checklist - Pull off the runway, cross the hold short line, stop and run the checklist.
2) Acronyms. GUMPS and PAIN CALL are the ones I use most often. They're useful when you're in the air and need to ensure you complete several items but you may not want to look in the cockpit or have yet another piece of paper floating around at that particular moment.
3) Memorized lists. These are harder to get right in the first place, but the rhythm can be used to ensure you don't miss anything. The ones I use are useful for all the planes I fly on a regular basis, though that means that some items are extraneous on some planes. For example, my cruise checklist: Trim, time, lights, pump, power, mixture, compass, cowl flaps. In the Mooney the pump isn't used except for priming, I have a slaved HSI, and there are no cowl flaps so I simply skip those items on that plane.
Those are all checklists. Some allow you to keep your head outside and/or your cockpit better organized. No sense picking nits over what a checklist is.
I don't look at checklists when I fly, I'm too busy with my hands full of airplane.
Try using trim.
If you're using them while you're in the air I hope you do it far from me.
How'd you pass your private pilot checkride without using any checklists?
How do you check someone's mental checklist? Perhaps you can have them rattle it off, but then it isn't a checklist, just a recitation.
As long as they can rattle it off consistently, it works as a checklist. Master, beacon, mixture, tank, pump, prime, clear, start, oil pressure, lean.
And like I said, the day the CFI hits me will be last day he or she flies with me and might result in reciprocation. It is just juvenile behavior and teaches nothing.
On that, we can agree.