IN Hg ALg. MANIFOLD  PRESS  25 5 15 30 20 10 35 110  100  90  80  70  60  50  110  100  90  80  70  60  50  E R  %RPM  3  4  I  0  2  2  I  3  VERTICAL SPEED  THOUSAND FT PER MIN  UP  DOWN  .5  .5  33  30  24  2I  I5  I2  6  3  TURN COORDINATOR  2 MIN.  D.C.  ELEC.  L R  NO PITCH  INFORMATION  2 MIN TURN  DC ELEC  L R  30.0  29.9  29.8  I 0 0 F E T I  4  5  6  7  9  2  0  8  3  CALIBRATED  TO 20,000 FEET  ALT  20 20  I0 I0 I0 I0 20 20  TEST  STBY PWR  20 20 I0 I0 I0 I0 20 20 TEST  STBY PWR  N  3  Figure 8-2.  The flight instruments for pitch control are the airspeed indicator, attitude indicator, altimeter, and vertical speed indicator . cruise is one bar width.  Figure 8-3.  The initial pitch correction at  normal cruise is one bar  width or less .$^{A}$ of the helicopter in relation  to the  natural horizon. During instrument flight, follow ex actly  the  sam e procedu re in  raising or lowering the miniature  aircraft in relation  to the  horizon bar.  There is some delay between control application and resultant  instrument change. This is the normal control lag in the  helicopter and should not be confused with instrument lag.  The attitude indicator may show small misrepresentations  of pitch attitude during maneuvers involving acceleration, deceleration, or turns. This precession error can be detected quickly by cross-checking the other pitch instruments.  If the miniature aircraft is properly adjusted on the ground,  it  may not require readjustment in flight. If the miniature aircra ft  is not on the horizon bar after level off at normal cruising airspeed, adjust it as necessary while maintaining level flig ht  with the other pitch instruments. Once the miniature  aircraft has been adjusted in level flight at normal cruising airspeed, leave it unchanged so it gives an accurate picture of pitch attitude at all times.  When making initial pitch attitude corrections to maintai n  altitude, the changes of attitude should be small and smoothl y  applied. The initial movement of the horizon bar should n ot  exceed one bar width high or low.  [Figure 8-3]  If a fur ther  adjustment is required, an additional correction of one - half bar normally corrects any deviation from the desired  altitude. This one-and-one-half bar correction is normally the  maximum pitch attitude correction from level flight attitude.  After making the correction, cross-check the other pitch  instruments to determine whether the pitch attitude change  is sufficient. If additional correction is needed to return to  altitude, or if the airspeed varies more than 10 knots from  that desired, adjust the power.  The altimeter gives an indirect indi cation of the pitch  attitude of the helicopter in  straight-and-level flight. Since  the altitude should remain constant in  level flight, deviation  from the desired altitude indicates a  need for a change in  pitch attitude and power as necessary. When losing altitude,  raise the pitch attitude and adjust power as necessary. When  gaining altitude, lower the pitch attitude and adjust power  as necessary. Indications for power changes are explained  in the next paragraph. The rate at which the altimeter moves helps to determine pitch  attitude. A very slow movement of the altimeter indicates  Altimeter 8-4