To use the alt flap, yes, but not as an alternate pitch control. My IP told me that the arrows on the panel were to warn of the direction of trim change, only because I would know what elevator to use to compensate. I only learned the real reason from another line pilot who had been trained in the US, a couple of years later. And the use of the flap as a pitch control is not covered in the manuals, so it probably does not have Boeing approval. I dunno! (and don't fly the Classic any more anyway)