snow showers, or night operations over unlit surfaces such  as water). Flight in conditions of limited visual contrast  should be avoided since this can result in a loss of horizontal  or surface reference, and obstacles such as wires become  perceptually invisible. To prevent spatial disorientation, loss  of control (LOC) or CFIT, pilots should slow the helicopter to a  speed that provides a controlled deceleration in the distance  equal to the forward visibility. The pilot should look for terrain  that provides sufficient contrast to either continue the flight  or to make a precautionary landing. If spatial disorientation  occurs and a climb into IMC is not feasible due to fuel state,  icing conditions, equipment, etc., make every effort to land  the helicopter with a slight forward descent to prevent any  sideward or rearward motion.  All helicopter pilots should receive training on avoidance  and recovery from inadvertent IMC with emphasis on  avoidance. An unplanned transition from VMC to IMC flight  is an emergency that involves a different set of pilot actions.  It requires the use of different navigation and operational  procedures, interaction with ATC, and crewmember resource  management (CRM). Consideration should be given to the  local flying area’s terrain, airspace, air traffic facilities, weather  (including seasonal affects such as icing and thunderstorms),  and available airfield/heliport approaches.  Training should emphasize the identification of  circumstances conducive to inadvertent IMC and a  strategy to abandon continued VFR flight in deteriorating  conditions. This strategy should include a minimum  altitude/airspeed combination that provides for an off­ 7-16  Whether it is a corporate or HAA operation, helicopter pilots  sometimes operate in challenging weather conditions. An  encounter with weather that does not permit continued  flight under VFR might occur when conditions do not allow  for the visual determination of a usable horizon (e.g., fog,  certified airspeed or flight below V$_{MINI}$ should be annotated  on the approach procedure. The distance also permits  optimal blending of obstacle clearance criteria with non- instrument heliport approach areas.  The visibility minimum is based on the distance from the  MAP to the heliport, among other factors (e.g., height  above the heliport elevation when at the MAP MDA). The  pilot is required to acquire and maintain visual contact  with the heliport final approach and takeoff (FATO) area  at or prior to the MAP. Obstacle or terrain avoidance from  the MAP to the heliport is the responsibility of the pilot.  Pilots need to level off when reaching the MDA, which  may occur before arriving at the MAP, until reaching the  visual approach angle on the approach path to clear the  obstacles. If the required weather minimums do not exist,  then the published MAP must be executed at the MAP  because IFR obstruction clearance areas are not applied to  the visual segment of the approach and a missed approach  segment protection is not provided between the MAP  and the heliport. As soon as practicable after reaching  the MAP, the pilot advises ATC whether cancelling IFR and  proceeding visually or executing the missed approach.  Inadvertent IMC  Figure 7-15. Point-in-space (PinS) approach examples for Part 91 and Part 135 operations.  Point-in-Space Approach Examples  Under Part 91, the operator flies the published IFR PinS approach procedure that has a charted MDA of 340 mean sea level (MSL)  and visibility of ¾ SM. When approaching the MAP at an altitude of 340 feet MSL, the pilot transitions from Instrument Meteorological  Conditions (IMC) to Visual Meteorological Conditions (VMC) and determines that the flight visibility is ½ SM. The pilot must determine  prior to the MAP whether the applicable basic VFR weather minimums can be maintained from the MAP to the heliport or execute a  missed approach. If the pilot determines that the applicable basic VFR weather minimums can be maintained to the heliport, the pilot  may proceed VFR. If the visual segment is in Class B, C, D, or the surface area of Class E airspace, it may require the pilot to obtain  a Special VFR clearance.  For an operator to proceed VFR under Part 135, a minimum visibility of ½ SM during the day and 1 SM at night with a minimum  ceiling of 300 feet. If prior to commencing the approach, the pilot determines the reported visibility is ¾ SM during the day, the pilot  descends IMC to an altitude no lower than the MDA and transitions to VMC. If the pilot determines prior to the MAP that the flight  visibility is less than ½ SM in the visual segment, a missed approach must be executed at the MAP.  EXAMPLE 1  EXAMPLE 2 