Airplane Flying Handbook

Drag
TAS 106KT
OAT 7°C
2
1
1
2
Drag
TAS 106KT
OAT 7°C
2
1
1
2
Yaw
string
Relative wind
Thrust
Yaw
string
Relative wind
Thrust
Rudder force
NAV1 108.00 113.00
NAV2 108.00 110.60
WPT _ _ _ _ _ _ DIS _ _ ._ NM DTK _ _ _ ° TRK 360°
134.000 118.000 COM1
123.800 118.000 COM2
130
120
4000
4300
4200
110
1
100
9
90
4100
60
4000
20
3900
NAV1 108.00 113.00
NAV2 108.00 110.60
WPT _ _ _ _ _ _ DIS _ _ ._ NM DTK _ _ _ ° TRK 360°
134.000 118.000 COM1
123.800 118.000 COM2
Figure 12-17. Excessive bank engine-out flight.
80
70
Excess bank toward operating engine, no rudder input.
XPDR 5537 IDNT LCL 10:12:34
3200
ALERTS
Result: large sideslip toward operating engine and greatly
3100
reduced climb performance.
For any multiengine airplane, zero sideslip can be confirmed
through the use of a yaw string. A yaw string is a piece of
string or yarn approximately 18 to 36 inches in length taped to
the base of the windshield or to the nose near the windshield
along the airplane centerline. In two-engine coordinated
flight, the relative wind causes the string to align itself with
the longitudinal axis of the airplane, and it positions itself
straight up the center of the windshield. This is zero sideslip.
Experimentation with slips and skids vividly displays the
location of the relative wind. Adequate altitude and flying speed
must be maintained while accomplishing these maneuvers.
With an engine set to zero thrust (or feathered) and the
airplane slowed to V YSE , a climb with maximum power on
VOR 1
270°
3800
4300
3600
3500
3400
3300
Bank toward operating engine, no sideslip.
Results: much lower drag and smaller control surface
deflections.
Figure 12-18. Zero sideslip engine-out flight.
130
120
110
1
100
9
90
80
70
VOR 1
270°
4000
4300
4200
4100
60
4000
20
3900
3800
4300
3600
3500
3400
3300
XPDR 5537 IDNT LCL 10:12:34
3200
ALERTS
3100
the remaining engine reveals the precise bank angle and
ball deflection required for zero sideslip and best climb
performance. Zero sideslip is again indicated by the yaw
string when it aligns itself vertically on the windshield. There
are very minor changes from this attitude depending upon the
engine failed (with non-counter-rotating propellers), power
available, airspeed and weight; but without more sensitive
testing equipment, these changes are difficult to detect.
The only significant difference would be the pitch attitude
required to maintain V YSE under different density altitude,
power available, and weight conditions.
12-25