Example Calculations - Kazan Helicopters Mi-17-1V Flight Manual

M,,·17·1B. Flight manual
1.7.7. Example Calculations
Example 1. Determine the maximum range and duration of the helicopter flight
in the ferrying version at an altitude of 500 m with the normal takeoff weight
TOW = 11100 kg, the total fuel load TF = 2514 kg and a reserve fuel of 5
%
of
the total fuel load.
Solution: The reserve fuel equals: RF = 2514 x 0.05 = 125.7 kg - 126 kg.
Fuel used in the horizontal flight (HFF) is calculated by the formula:
HFF = TF- GF - CF - LF - RF - UF, where
TF= 2514 kg - total fuel load;
GF= 35 kg - fuel used on the ground;
TF - GF = TOF = 2514 - 35 = 2479 kg - takeoff fuel load;
CF=30 kg - fuel used during takeoff and climb to 500 m;
LF= 25 kg - fuel used in descent from 500 m and landing;
UF= 20 kg - unusable fuel;
HFF= 2514 - 35 - 30 - 25 - 20 -126
=
2278 kg.
Helicopter operational weight with zero fuel:
OZFW = TOW - TOF = 11100 - 2479 - 8620 kg.
Helicopter gross weight at the initial point of horizontal flight segment:
IHW = TOW - CF = 11100 - 30 = 11070 kg.
Helicopter gross weight at the end of horizontal flight segment:
EHW = OZFW
+
RF
+
UF
+
LP = 8620
+
126
+
20
+
25
=
8791 kg.
Helicopter average gross weight at the horizontal flight segment:
AGFW = IHW
+
EHW = 8791
+
11070 = 9930kg
2 2
Use the graphs in Figs 1.5 and 1.6 to derive the minimum fuel consumption per
kilometer at the cruising lAS and the minimum hourly consumption at the economic
lAS for the helicopter average gross weight in horizontal flight segment:
q = 2.59 kg/km (cruising lAS = 230 km/h)
Q = 496 kg/h (economic lAS = 130 km/h)
Horizontal flight range at cruising speed:
HFR =f:l£r=
=_}2_?~~g
-.
=
879.5km
~
880km
q 2.59kg/km
Distances in climb and descent (Ref. Tables 1.3 and 1.4) are equal to 0 and
5 km respectively.
Service range (SR): SR
=
HFR + CD + DD
SR = 880 + 5 + 0 = 885 km.
Duration of horizontal flight at the economic speed:
HFT
=
.':!!"£
=
2278
=
4.593h
=
4h36 min
Q
496
Duration of flight in climb and descent (Ref. Tables 1.3 and 1.4) is 2 min
(0.033 h) and 3 min (0.05 h) respectively.
Service duration of flight (ST): ST = HFT + CT + DT
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