200  245  I50  I00  75  °F  P  S  I  II5  60  I00  20  0  OIL  P  R  E  S  T  E  M  P  Minimum  Maximum  Normal operating range  RPM HUNDREDS 25 3 5 I5 30 20 I0 35 25  5  I5  30  20  I0  HOURS  AVOID  CONTINUOUS  OPERATION  BETWEEN 2250  AND 2350 RPM  I  I0  IN Hg  ALg.  MANIFOLD  PRESSURE  35 50 10 15 25 40 30 20 45 35  10  15  25  40  30  20  140 160  200  250  AIRSPEED  KNOTS  IAS  TAS  40  60  80  100  120 140  160  180  200  260  9-3  Figure 9-4.  Manifold pressure gauge (top) and tachometer (bottom). Figure 9-2.  Multi-engine air sp eed indicator.  Figure 9-3.  Minimum, maximum, and normal operating range  markings on oil gauge.  Figure 9-1.  Single-engine air sp eed indicator.  a red radial line and the normal operating range with a green  arc.  [Figure 9-4]  Some instruments may have a yellow arc  to indicate a caution area.  In addition to the  markings listed above, small multi-engine  airplanes have a red ra dial line to indicate single-engine  minimum controllable a irspeed (V$_{MC}$). A blue radial line  is used to indicate  single-engine best rate of climb speed at  maximum weight at sea level (V$_{YSE}$).  [Figure 9-2]  The Powerplant Limita tions portion describes operating  limitations on an aircraft’s reciprocating or turbine engine(s).  Thes include limitations for takeoff power, maximum  continuous power, and maximum normal operating power,  which is the maximum power the engine can produce without  any restrictions and is depicted by a green arc. Other items  that can be included in this area are the minimum and  maximum oil and fuel pressures, oil and fuel grades, and  propeller operating limits. [Figure 9-3]  Weight and Loading Distribution contains the maximum  certificated weights, as well as the center of gravity (CG)  range. The location of the reference datum used in balance  computations is included in this section. Weight and balance  computations are not provided in this area, but rather in the  weight and balance section of the AFM/POH.  All reciprocating-engine powered aircraft must have a  revolutions per minute (rpm) indicator for each engine.  Aircraft equipped with a constant-speed propeller or rotor  system use a manifold pressure gauge to monitor power  output and a tachometer  to monitor propeller or rotor speed.  Both instruments depict  the maximum operating limit with  Weight and Loading Distribution  Powerplant 