DownIn3Green:
The wind noise outside the windows, the feeling of the aircraft, the flap settings, etc ad nausem...The Captain should look at an inop A/S indicator as just another bump in the road...
My father instructed in AT-6 Texans/Harvards 70 years ago. He told me about a portion of the curriculum in which part of the student's ASI was masked, so that the trainee gained exactly the above skills. He considered it a valuable tool in his arsenal of skills.