So what you are saying is you never get anything wrong or never mis judge an anything,
I once thought I was wrong, but I was mistaken.
if you are performing an emergency landing due to engine failure that once you have committed to a field and lowered flaps then realised the approach is not working out correctly you would just continue regardless even if by raising some flap that extended the glide to land safely just because it is not written in a manual
I have only force landed four times. I've never hurt a plane doing it. My training and practice is to not extend flaps to "drag" (beyond 20 in a Cessna) until landing at the intended place (or at least a suitable place) is very confident. I have slipping as an established, trained and described procedure, to modulate my glidepath, power on or off, as I need, if I got ti wrong enough, that continuing is appropriate, I can go around if I was "mistaken". I use drag flap when that drag is appropriate to the approach, and not before.
I recall that Genghis kindly provided an authoritative reference earlier in this thread, that the modulation of the flaps in the BA 777 LHR crash was not determined to be beneficial, but I do not have first hand knowledge of this event, nor flying 777's. But, I don't accept that event as persuasive that modulation of flaps is a good idea for normal operation.
This thread has an air of suggesting that pilots should be innovative. I can't argue innovative
thinking, but I feel that pilots should be innovative
within the conventional training, and aircraft operating norms. You can always cite rare extreme situations which demonstrate out of the box thinking, and isn't that nice, but those situations are a long way from a public forum directed toward GA pilots of average skill and experience. I think of the Sioux City Iowa DC-10, we're just not doing that stuff in 172's.
If a pilot does something innovative, which saves lives and property, pat them on the back for a job well done. But be very careful of adding that new technique to the norm, for everyone to include in their day to day flying - that's a huge stretch. We still have the occasional convenience store owner who stands up to a robber and succeeds. But we will always have the authorities say afterwords that the safer thing to do is to hand over the money, and not take risks. If the engine quits, it's safer to follow established techniques to maintain a stabilized - non distracted glide, to a suitable site. The final approach stage of a gliding forced landing in a 172 is NOT the time and place for a GA pilot to start innovating - focus on the task.
So you won't see me on here promoting an unestablished technique which can take the user toward real risk. Modulating the flaps of a 172 500 feet up on approach is not risky, I agree with that - it's just sloppy and needless technique. But modulating the flaps in the same way at 50 feet up will be
very dangerous.
In light of the constant complaints about the cost of certified aircraft, do people seriously want the effort expended to test and approve this procedure, and define in pages of data, reports, and flight manual procedures when it may be applied, how, and when it is not safe to do? It's much more cost effective to not endorse it at all - because good flying technique will never call upon it - and keep things more simple.
A C152 aerobat has removable doors. Would you just take them off on a nice day for that breezy feeling while flying? Or would you seek out a two door off approval (which does not exist) to allow that aircraft to be flown with both doors off? Fly the plane in the established configuration.... Or, pay the flight test costs to gather the data to define how the new procedure/configuration might be safely flown. I have approved my 150 to fly with either door off - I innovated, and I paid the approval cost for that.