Aircraft Performance
File Name: Exercise_3
Exercise 3: Aircraft Performance
Given Aircraft Conditions:
Gross Weight for Cruise = 300,000 lbs
Wing Area = 3050 ft
2
Wing Span = 156 ft
Wing Efficiency = .75
CDp
= 0.0119
Twin turbofan engine Aircraft
Temp-Standard
Figure 2.1 Atmospheric Conditions
Figures 4.3 and 4.5
1. Find Stall Speed “Stick Shaker” (KEAS) and Body AOA for Flaps 0 and Flaps 30
Configurations (Figure 4.3). Assume Wing area increases are adjusted in reported CL
values.
2. Find L/D max. Flaps 0 and ignore the effects of compressibility with respect to C
L
and C
D
(Figure 4.5).
3. Find Best Endurance Airspeed (KEAS) and Mach number at FL350. Flaps 0 and ignore
compressibility effects on C
L and C
D
.
4. Find Body Angle of Attack associated with Best Endurance Airspeed. (Ignore effects of
compressibility with respect to C
L
and C
D
).
5. Find Best Glide ratio and Distance Traveled (nm) at Best Glide AOA/Airspeed if the aircraft
lost both engines at 35,000 ft (no wind).
a. What is the glide path angle (deg)?
b. What is the Pitch attitude (deg) using AOA from Question 4.
6. Using Equation 5.2, find Thrust Required (Drag) to maintain FL350 at best endurance speed
(Flaps-0) and given Cruise Weight. (Ignore Compressibility Effects on Drag and see Figure
4.5.)
7. Using Equations 5.7/5.10/5.11, find Total Drag, Parasite Drag, and Induced Drag at FL350
(35,000 Pressure Altitude) at Max Endurance Speed and then compare to Problem 6.
8. Using Equation 5.14, find Power Required (hp) at FL350 Max Endurance Airspeed.
9. Use Figure 5.1, given Sea Level conditions, and find the following:
A. Max Endurance Mach.
B. Thrust Required at Min Drag.
C. Max Range Mach (with and without Mach Drag Rise).
D. Thrust Required at Max Range (with and without Mach Drag Rise).