Controlled Flight Into Terrain (CFIT) occurs when an airworthy aircraft is flown, under the control of a qualified pilot, into terrain (water or obstacles) with inadequate awareness on the part of the pilot of the impending collision.
91.119 Minimum safe altitudes: General
91.121 Altimeter settings
RMH Appendix C CFIT Checklist
AC 61-134 General Aviation
Controlled Flight Into
Terrain Awareness