Which is not particularly clever on a powered approach - you are NEVER 'sure of making the RW' until you cross the threshold, which is far too late to wait to select full flap.
Slight generalisation - should've read: "sure of making the usable runway surface"... but regardless, this particular debate regarding when to lower landing flap must surely be airfield specific?
To elaborate: The above procedure was introduced at a US institution I was with some years ago after a PA-28 fell short of the undershoot on approach following an engine failure. The NTSB investigation commented that had the pilot delayed lowering full flap "until sure of making the useable runway surface" (or words to that affect) then damage to the aircraft would have been reduced because it would not have landed on the approach lighting.
But in my experience, in the USA they try to teach student pilots how to actually
fly an aeroplane whereas over here I get the distinct impression that we're encouraged to teach students merely how to
cope with one. Flying exercises within the JAR PPL syllabus that actually deal solely with developing raw handling skills are sadly lacking IMHO and very soon someone here will pipe up about upsetting the aircraft configuration at the last minute being dangerous because the (basic) skills to handle it are not taught.
I do believe a certain Capt.Sullenburger will back me up here...
VFE.