Embraer EMB145 - Page 674

PERFORMANCE
EMB-145 LB
AIRPLANE
OPERATIONS
MANUAL
1-04-20
Page
2
Code
02
REVISION 40
The equivalent obstacle height to be used in a obstacle clearance
calcula
tion is:
H
E
= H
A
+ ΔH
1
+ ΔH
2
+ ......+ ΔH
n
where:
H
E
= equivalent obstacle height
H
A
= actual obstacle height
ΔH
1, 2, n
= height increments for each distance portion flown in
turn to the obstacle.
2) WIND EFFECT ON THE FLIGHT PATH
a) STRAIGHT FLIGHT PORTIONS
Considering the drift compensation, the straight portions of the
f
light path m
ay be corrected to still air equivalent distance as
follows:
SAD
GD TAS
GS
=
×
Where:
SAD = still air equivalent distance
GD = actual ground distance
TAS = airplane true airspeed (obtained from the radius
of
turns and s
peed conversion chart)
GS = airplane ground speed
For straight flight:
GS = TAS + (V
W
x cosα)
Where:
V
W
= wind speed
α = angle between flight direction and wind direction
Rem
arks:
V
W
x cosα is negative for a head wind component
V
W
x cosα is positive for a tailwind component
b) TURNING FLIGHT PORTIONS
Two effects must be taken into account:
b1) Trajectory Displacement:
The trajectory is displaced in the wind component
dir
ecti
on proportionally to the time.
The displacement may be calculated by:
AOM-145/1114