Please expain me the answer to this question. I'll be really thankful.
Because the VSI measures the rate of change of static pressure and not actual values of static pressure, position error :
a) never affects VSI indications.
b) only causes errors in the VSI during take-off.
c) causes errors in the VSI indications whenever airspeed is changed, if at the same time there is a change in position error.
d) causes errors in VSI indications whenever airspeed is changed, even if there is no change in position error.
According to book (b) is correct. But i think (d) should be the correct option. I know the error is most noticeable during the take-off phase but error should also occur everytime the airspeed is changed. Not just during the take-off phase.