TM 1-1510-224-10 normal  aircraft  static  air  system.    The  data  is  shown  on two graphs.  One graph is for airspeeds between 80 and 200 knots with lines for flaps down with gear down, flaps approach  with  gear  down,  and  flaps  approach  with  gear up.    The  other  graph  is  for  airspeeds  between  100  and 250  knots  with  lines  for  flaps  up  with  gear  down  and flaps up with gear up.  The indicated airspeed values on this graph assume zero instrument error. d. Altimeter Correction - Normal System. (1) Description.      The   Altimeter   Correction   - Normal  System  graph  (fig.    7A-4)  provides  the  altitude correction  to  be  made  to  the  altimeter  reading  when  the normal aircraft static source is being used. (2) Purpose.  This graph is used to determine altimeter   correction   factors   to   be   added   to   indicated altitude  for  flaps  settings  of  up,  approach,  and  down  at various indicated airspeeds to find true pressure altitude for  a  given  indicated  pressure  altitude.    The  indicated airspeed  values  on  this  graph  assume  zero  instrument error. e. Airspeed Calibration - Alternate System. (1) Description.      The   Airspeed   Calibration   - Alternate     System     graph     (fig.          7A-5)     depicts     the relationship  between  indicated  airspeed  and  calibrated airspeed for the alternate aircraft static air source. (2) Purpose.  This graph is used to determine calibrated  airspeed  for  a  given  indicated  airspeed  using the alternate aircraft static air system. f. Altimeter Correction - Altemate System. (1) Description.      The   Altimeter   Correction   - Alternate  System  graph  (fig.    7A-6)  provides  the  altitude correction  to  be  made  to  the  altimeter  reading  when  the alternate aircraft static air source is being used. (2) Purpose.  This graph is used to determine altimeter  correction  factors  to  be  added  or  subtracted  to indicated   altitude   for   a   given   indicated   airspeed   and pressure altitude. g. Indicated Outside Air Temperature Correction. (1) Description.  The Indicated Outside Air Temperature    Correction    graph    (fig.        7A-7)    provides temperature  corrections  to  be  made  to  indicated  free  air temperature to obtain true free air temperature. (2) Purpose.  This graph is used to determine the correction factor which must be added to the reading on  the  free  air  temperature  gage  to  obtain  true  free  air temperature at a given calibrated airspeed and pressure altitude.        The    graph    assumes    standard    day    (ISA) conditions. h. ISA Conversion. (1) Description.    The   ISA   Conversion   graph (fig.  7A-8) allows conversion to ISA. (2) Purpose.  This graph is used to convert to SA,  given  free  air  temperature  in  degrees  Celsius  and pressure altitude in feet. i. Fahrenheit to Celsius Temperature Conversion. (1) Description.      The   Fahrenheit   to   Celsius Temperature  Conversion  graph  (fig.    7A-9)  depicts  the relationship between temperature in degrees Fahrenheit and degrees Celsius. (2) Purpose.    This  graph  is  used  to  convert from  degrees  Fahrenheit  to  degrees  Celsius  or  degrees Celsius to degrees Fahrenheit. j. Static  Take-off  Power  at  1700  RPM,  Ice  Vanes Retracted or Extended. (1) Description.  The Static Take-off Power at 1700   RPM,   Ice   Vanes   Retracted   or   Extended   graphs (fig.  7A-10  and  7A-11)  depict  the  power  which  must  be available for takeoff without exceeding engine limitations. (2) Purpose.        These    graphs    are    used    to determine  static  take-off  power  available  at  1700  RPM for  a  given  free  air  temperature  in  degrees  Celsius  and field  pressure  altitude  in  feet.    One  graph  is  provided  for ice    vanes    retracted    and    the    other    for    ice    vanes extended.  Torque will increase with increasing airspeed. k. Wind Components. (1) Description.          The     Wind     Components graph  (fig.    7A-12)  allows  conversion  of  wind  direction, wind speed, and angle between wind direction and flight path to headwind and crosswind speed components. (2) Purpose.  This graph is used to determine the  headwind  component  and  crosswind  component  in knots   when   the   wind   speed   in   knots   and   the   angle between the wind direction and flight path in degrees are known. I. Maximum Take-off Weight Permitted by Enroute Climb Requirements. (1) Description. The Maximum Take-off Weight Permitted by Enroute Climb Requirements graph 7A-2