N 3 33
2 I
VERTICAL SPEED
THOUSAND FT PER MIN
UP
DOWN
.5
.5
30 24
2I
I2 6
2 MIN TURN
DC ELEC
L R
30.0 29.9 29.8
I00 FEET
4 5 6
CALIBRATED
TO
20,000 FEET
ALT
20 20
I0 I0
I0 I0
20 20
TEST STBY PWR
IN Hg
ALg.
MANIFOLD
PRESS
E R
%RPM
6-7a Flight instrument indications in straight-and-level flight with power increasing. Figure 8-7. Flight instrument indications in straight-and-level flight with power increasing.
If the altitude is held constant, power determines the airspeed.
For example, at a constant altitude, cruising power results
in cruising airspeed. Any deviation from the cruising power
setting results in a change of airspeed. When power is added
to increase airspeed, the nose of the helicopter pitches up and
yaws to the right in a helicopter with a counterclockwise main
rotor blade rotation. [Figure 8-7] When power is reduced
to decrease airspeed, the nose pitches down and yaws to the
left. [Figure 8-8] The yawing effect is most pronounced
in single-rotor helicopters and is absent in helicopters with
counter-rotating rotors. To counteract the yawing tendency
of the helicopter, apply pedal trim during power changes.
To maintain a constant altitude and airspeed in level flight,
coordinate pitch attitude and power control. The relationship
between altitude and airspeed determines the need for a
change in power and/or pitch attitude. If the altitude is
constant and the airspeed is high or low, change the power to
obtain the desired airspeed. During the change in power, make
an accurate interpretation of the altimeter, then counteract
any deviation from the desired altitude by an appropriate
change of pitch attitude. If the altitude is low and the airspeed
is high, or vice versa, a change in pitch attitude alone may
return the helicopter to the proper altitude and airspeed. If
both airspeed and altitude are low, or if both are high, changes
in both power and pitch attitude are necessary.
To make power control easy when changing airspeed, it is
necessary to know the approximate power settings for the
various airspeeds at which the helicopter is flown. When the
airspeed is to be changed by any appreciable amount, adjust
the power so that it is over or under that setting necessary
to maintain the new airspeed. As the power approaches the
desired setting, include the manifold pressure in the cross-
check to determine when the proper adjustment has been
accomplished. As the airspeed is changing, adjust the pitch
attitude to maintain a constant altitude. A constant heading
should be maintained throughout the change. As the desired
airspeed is approached, adjust power to the new cruising
power setting and further adjust pitch attitude to maintain
altitude. The instrument indications for straight-and-level
flight at normal cruise and during the transition from normal
cruise to slow cruise are illustrated in Figures 8-9 and 8-10.
After the airspeed stabilizes at slow cruise, the attitude
indicator shows an approximate level pitch attitude.
The altimeter is the primary pitch instrument during level
flight, whether flying at a constant airspeed or during a
change in airspeed. Altitude should not change during
airspeed transitions, and the heading indicator remains the
primary bank instrument. Whenever the airspeed is changed
by an appreciable amount, the manifold pressure gauge is
momentarily the primary instrument for power control.
When the airspeed approaches the desired reading, the
airspeed indicator again becomes the primary instrument
for power control.
N 3 33
2 I
VERTICAL SPEED
THOUSAND FT PER MIN
UP
DOWN
.5
.5
30 24
2I
I2 6
2 MIN TURN
DC ELEC
L R
30.0 29.9 29.8
I00 FEET
4 5 6
CALIBRATED
TO
20,000 FEET
ALT
20 20
I0 I0
I0 I0
20 20
TEST STBY PWR
IN Hg
ALg.
MANIFOLD
PRESS
E R
%RPM
6-7b Flight instrument indications in straight-and-level flight with power decreasing. Figure 8-8. Flight instrument indications in straight-and-level flight with power decreasing.
A O M
N 3 33
2 I
VERTICAL SPEED
THOUSAND FT PER MIN
UP
DOWN
.5
.5
30 24
2I
I2 6
2 MIN TURN
DC ELEC
L R
30.0 29.9 29.8
I00 FEET
4 5 6
CALIBRATED
TO
20,000 FEET
ALT
20 20
I0 I0
I0 I0
20 20
TEST STBY PWR
IN Hg
ALg.
MANIFOLD
PRESS
E R
%RPM
Primary pitchSupporting pitch and bank
Supporting bank Primary bank Supporting pitchPrimary power
Remains constant
Figure 6-6. Flight instrument indications in straight-and level flight at normal cruise speed.Figure 8-9. Flight instrument indications in straight-and-level flight at normal cruise speed.
A O M
N 3 33
2 I
VERTICAL SPEED
THOUSAND FT PER MIN
UP
DOWN
.5
.5
30 24
2I
I2 6
2 MIN TURN
DC ELEC
L R
IN Hg
ALg.
MANIFOLD
PRESS
E R
%RPM
30.0 29.9 29.8
I00 FEET
4 5 6
CALIBRATED
TO
20,000 FEET
ALT
20 20
I0 I0
I0 I0
20 20
TEST STBY PWR
Primary pitchSupporting pitch and bank
Supporting bank Primary bank Supporting pitch
Primary power as airspeed
approaches desired value
Remains constant
Figure 6-7. Flight instrument indications in straight-and level flight with airspeed decreasing. Figure 8-10. Flight instrument indications in straight-and-level flight with airspeed decreasing.
increase power to the climb power setting and adjust pitch
attitude to the approximate climb attitude. A helicopter may
or may not have an exact “climb attitude.” To slow down
to climb (versus cruise) airspeed, the nose must be raised.
Depending on power and horizontal stabilizer configuration
and effectiveness, the nose may be level during an established
climb or slightly nose high. Many helicopters are very capable
of climbing and never raising the nose. A short deceleration
period may be necessary to slow to a more efficient climb
airspeed, but the attitude indicator is often level after
the climb is stabilized. The increase in power causes the
helicopter to start climbing and only very slight back cyclic
pressure is needed to complete the change from level to climb
attitude. The attitude indicator should be used to accomplish
the pitch change. If the transition from level flight to a climb
is smooth, the VSI shows an immediate upward trend and
then stops at a rate appropriate to the stabilized airspeed and
attitude. Primary and supporting instruments for climb entry
are illustrated in Figure 8-11.
When the helicopter stabilizes at a constant airspeed and
attitude, the airspeed indicator becomes primary for pitch.
The manifold pressure continues to be primary for power and
should be monitored closely to determine if the proper climb
power setting is being maintained. Primary and supporting
instruments for a stabilized constant airspeed climb are shown
in Figure 8-12.
To produce straight-and-level flight, the cross-check of the
pitch-and-bank instruments should be combined with the
power control instruments. With a constant power setting, a
normal cross-check should be satisfactory. When changing
power, the speed of the cross-check must be increased to
cover the pitch and bank instruments adequately. This is
necessary to counteract any deviations immediately.
Common Errors During Airspeed Changes
1. Improper use of power
2. Overcontrolling pitch attitude
3. Failure to maintain heading
4. Failure to maintain altitude
5. Improper pedal trim
Straight Climbs (Constant Airspeed and
Constant Rate)
For any power setting and load condition, there is only
one airspeed that gives the most efficient rate of climb.
To determine this, consult the climb data for the type of
helicopter being flown. The technique varies according to
the airspeed on entry and whether a constant airspeed or
constant rate climb is made.
Entry
To enter a constant airspeed climb from cruise airspeed when
the climb speed is lower than cruise speed, simultaneously
A O M
N 3 33
2 I
VERTICAL SPEED
THOUSAND FT PER MIN
UP
DOWN
.5
.5
30 24
2I
I2 6
2 MIN TURN
DC ELEC
L R
30.0 29.9 29.8
I00 FEET
4 5 6
CALIBRATED
TO
20,000 FEET
ALT
20 20
I0 I0
I0 I0
20 20
TEST STBY PWR
IN Hg
ALg.
MANIFOLD
PRESS
E R
%RPM
Primary pitch
Supporting pitch and bank
Supporting bank Primary bank Supporting pitch
Remains constant
Primary power
Primary pitch
Figure 6-9. Flight instrument indications in a stabilized, constant-airspeed climb.
Figure 8-11. Flight instrument indications during climb entry for a constant-airspeed climb.
A O M
N 3 33
2 I
VERTICAL SPEED
THOUSAND FT PER MIN
UP
DOWN
.5
.5
30 24
2I
I2 6
2 MIN TURN
DC ELEC
L R
30.0 29.9 29.8
I00 FEET
4 5 6
CALIBRATED
TO
20,000 FEET
ALT
20 20
I0 I0
I0 I0
20 20
TEST STBY PWR
IN Hg
ALg.
MANIFOLD
PRESS
E R
%RPM
Primary pitch
Supporting pitch and bank
Supporting bank Primary bank Supporting pitch
Remains constant
Primary power
Primary pitch
Figure 6-9. Flight instrument indications in a stabilized, constant-airspeed climb. Figure 8-12. Flight instrument indications in a stabilized constant-airspeed climb.
A O M
N 3 33
2 I
VERTICAL SPEED
THOUSAND FT PER MIN
UP
DOWN
.5
.5
30 24
2I
I2 6
2 MIN TURN
DC ELEC
L R
30.0 29.9 29.8
I00 FEET
4 5 6
CALIBRATED
TO
20,000 FEET
ALT
20 20
I0 I0
I0 I0
20 20
TEST STBY PWR
IN Hg
ALg.
MANIFOLD
PRESS
E R
%RPM
Primary power
Supporting direct pitch and bank
Supporting bank Primary bank Primary pitch
Remains constant
Figure 6-10. Flight instrument indications in a stabilized, constant-rate climb.Figure 8-13. Flight instrument indications in a stabilized constant-rate climb.
The technique and procedures for entering a constant rate climb
are very similar to those previously described for a constant
airspeed climb. For training purposes, a constant rate climb is
entered from climb airspeed. Use the rate appropriate for the
particular helicopter being flown. Normally, in helicopters with
low climb rates, 500 fpm is appropriate. In helicopters capable
of high climb rates, use a rate of 1,000 fpm.
To enter a constant rate climb, increase power to the
approximate setting for the desired rate. As power is applied,
the airspeed indicator is primary for pitch until the vertical
speed approaches the desired rate. At this time, the VSI
becomes primary for pitch. Change pitch attitude by reference
to the attitude indicator to maintain the desired vertical speed.
When the VSI becomes primary for pitch, the airspeed
indicator becomes primary for power. [Figure 8-13] Adjust
power to maintain desired airspeed. Pitch attitude and power
corrections should be closely coordinated. To illustrate this,
if the vertical speed is correct but the airspeed is low, add
power. As power is increased, it may be necessary to lower
the pitch attitude slightly to avoid increasing the vertical rate.
Adjust the pitch attitude smoothly to avoid overcontrolling.
Small power corrections are usually sufficient to bring the
airspeed back to the desired indication.
Level Off
The level off from a constant airspeed climb must be started
before reaching the desired altitude. Although the amount
of lead varies with the type of helicopter being flown and
pilot technique, the most important factor is vertical speed.
As a rule of thumb, use 10 percent of the vertical velocity
as the lead point. For example, if the rate of climb is 500
fpm, initiate the level off approximately 50 feet before the
desired altitude. When the proper lead altitude is reached, the
altimeter becomes primary for pitch. Adjust the pitch attitude
to the level flight attitude for that airspeed. Cross-check the
altimeter and VSI to determine when level flight has been
attained at the desired altitude. If cruise airspeed is higher
than climb airspeed, leave the power at the climb power
setting until the airspeed approaches cruise airspeed, and
then reduce it to the cruise power setting. The level off from
a constant rate climb is accomplished in the same manner as
the level off from a constant airspeed climb.
Straight Descents (Constant Airspeed
and Constant Rate)
A descent may be performed at any normal airspeed the
helicopter can attain, but the airspeed must be determined
prior to entry. The technique is determined by the type of
descent, a constant airspeed, or a constant rate.
Entry
If airspeed is higher than descending airspeed, and a constant
airspeed descent is desired, reduce power to a descent
power setting and maintain a constant altitude using cyclic
pitch control. This slows the helicopter. As the helicopter
approaches the descending airspeed, the airspeed indicator
becomes primary for pitch and the manifold pressure is
primary for power. Holding the airspeed constant causes the
helicopter to descend. For a constant rate descent, reduce the
power to the approximate setting for the desired rate. If the
descent is started at the descending airspeed, the airspeed
indicator is primary for pitch until the VSI approaches the
desired rate. At this time, the VSI becomes primary for
pitch, and the airspeed indicator becomes primary for power.
Coordinate power and pitch attitude control as previously
described on page 8-10 for constant rate climbs.
Level Off
The level off from a constant airspeed descent may be
made at descending airspeed or at cruise airspeed, if this is
higher than descending airspeed. As in a climb level off, the
amount of lead depends on the rate of descent and control
technique. For a level off at descending airspeed, the lead
should be approximately 10 percent of the vertical speed. At
the lead altitude, simultaneously increase power to the setting
necessary to maintain descending airspeed in level flight. At
this point, the altimeter becomes primary for pitch, and the
airspeed indicator becomes primary for power.
To level off at an airspeed higher than descending airspeed,
increase the power approximately 100 to 150 feet prior to
reaching the desired altitude. The power setting should be that
which is necessary to maintain the desired airspeed in level
flight. Hold the vertical speed constant until approximately
50 feet above the desired altitude. At this point, the altimeter
becomes primary for pitch and the airspeed indicator becomes
primary for power. The level off from a constant rate descent
should be accomplished in the same manner as the level off
from a constant airspeed descent.
Common Errors During Straight Climbs and
Descents
1. Failure to maintain heading
2. Improper use of power
3. Poor control of pitch attitude
4. Failure to maintain proper pedal trim
5. Failure to level off on desired altitude
Turns
Turns made by reference to the flight instruments should
be made at a precise rate. Turns described in this chapter
are those not exceeding a standard rate of 3° per second
as indicated on the turn-and-slip indicator. True airspeed
determines the angle of bank necessary to maintain a standard
rate turn. A rule of thumb to determine the approximate angle
of bank required for a standard rate turn is to use 15 percent
of the airspeed. A simple way to determine this amount is
to divide the airspeed by 10 and add one-half the result. For
example, at 60 knots approximately 9° of bank is required
(60 ÷ 10 = 6, 6 + 3 = 9); at 80 knots approximately 12° of
bank is needed for a standard rate turn.
To enter a turn, apply lateral cyclic in the direction of the
desired turn. The entry should be accomplished smoothly,
using the attitude indicator to establish the approximate bank
angle. When the turn indicator indicates a standard rate turn,
it becomes primary for bank. The attitude indicator now
becomes a supporting instrument. During level turns, the
altimeter is primary for pitch, and the airspeed indicator is
primary for power. Primary and supporting instruments for a
stabilized standard rate turn are illustrated in Figure 8-14. If
an increase in power is required to maintain airspeed, slight
forward cyclic pressure may be required since the helicopter
tends to pitch up as collective pitch is increased. Apply pedal
trim, as required, to keep the ball centered.
To recover to straight-and-level flight, apply cyclic in the
direction opposite the turn. The rate of roll-out should be the
same as the rate used when rolling into the turn. As the turn
recovery is initiated, the attitude indicator becomes primary
for bank. When the helicopter is approximately level, the
heading indicator becomes primary for bank as in straight-
and-level flight. Cross-check the airspeed indicator and ball
closely to maintain the desired airspeed and pedal trim.
Turn to a Predetermined Heading
A helicopter turns as long as its lateral axis is tilted;
therefore, the recovery must start before the desired heading
is reached. The amount of lead varies with the rate of turn
and piloting technique.
As a guide, when making a 3° per second rate of turn, use a
lead of one-half the bank angle. For example, if using a 12°
bank angle, use half of that, or 6°, as the lead point prior to the
desired heading. Use this lead until the exact amount required
by a particular technique can be determined. The bank angle
should never exceed the number of degrees to be turned.
As in any standard rate turn, the rate of recovery should be
the same as the rate of entry. During turns to predetermined
headings, cross-check the primary and supporting pitch, bank,
and power instruments closely.
Timed Turns
A timed turn is a turn in which the clock and turn-and-slip
indicator are used to change heading a definite number of
degrees in a given time. For example, using a standard rate
turn, a helicopter turns 45° in 15 seconds. Using a half-standard
rate turn, the helicopter turns 45° in 30 seconds. Timed turns
can be used if the heading indicator becomes inoperative.
A O M
N 3 33
2 I
VERTICAL SPEED
THOUSAND FT PER MIN
UP
DOWN
.5
.5
2I I5
2 MIN TURN
DC ELEC
L R
30.0 29.9 29.8
I00 FEET
4 5 6
CALIBRATED
TO
20,000 FEET
ALT
20 20
I0 I0
I0 I0
20 20
TEST STBY PWR
IN Hg
ALg.
MANIFOLD
PRESS
E R
%RPM
Primary bank initially
Supporting pitch
Primary bank as
turn is established
Supporting pitch
Primary pitch
Remains constant
Figure 6-11. Flight instrument indications in a stabilized turn to the left.
Primary power
Figure 8-14. Flight instrument indications in a standard-rate turn to the left.
Prior to performing timed turns, the turn coordinator should
be calibrated to determine the accuracy of its indications.
To do this, establish a standard rate turn by referring to the
turn-and-slip indicator. Then, as the sweep second hand of
the clock passes a cardinal point (12, 3, 6, or 9), check the
heading on the heading indicator. While holding the indicated
rate of turn constant, note the heading changes at 10-second
intervals. If the helicopter turns more or less than 30° in
that interval, a smaller or larger deflection of the needle is
necessary to produce a standard rate turn. After the turn-
and-slip indicator has been calibrated during turns in each
direction, note the corrected deflections, if any, and apply
them during all timed turns.
Use the same cross-check and control technique in making
timed turns that is used to make turns to a predetermined
heading, but substitute the clock for the heading indicator.
The needle of the turn-and-slip indicator is primary for
bank control, the altimeter is primary for pitch control, and
the airspeed indicator is primary for power control. Begin
the roll-in when the clock’s second hand passes a cardinal
point; hold the turn at the calibrated standard rate indication
or half-standard rate for small changes in heading; then
begin the roll-out when the computed number of seconds
has elapsed. If the roll-in and roll-out rates are the same, the
time taken during entry and recovery need not be considered
in the time computation.
If practicing timed turns with a full instrument panel,
check the heading indicator for the accuracy of the turns.
If executing turns without the heading indicator, use the
magnetic compass at the completion of the turn to check turn
accuracy, taking compass deviation errors into consideration.
Change of Airspeed in Turns
Changing airspeed in turns is an effective maneuver for
increasing proficiency in all three basic instrument skills.
Since the maneuver involves simultaneous changes in all
components of control, proper execution requires a rapid
cross-check and interpretation, as well as smooth control.
Proficiency in the maneuver also contributes to confidence in
the instruments during attitude and power changes involved
in more complex maneuvers.
Pitch and power control techniques are the same as those
used during airspeed changes in straight-and-level flight.
As discussed previously, the angle of bank necessary for a
given rate of turn is proportional to the true airspeed. Since
the turns are executed at standard rate, the angle of bank
must be varied in direct proportion to the airspeed change in
order to maintain a constant rate of turn. During a reduction
of airspeed, decrease the angle of bank and increase the pitch
attitude to maintain altitude and a standard rate turn.