# Extra Homework 5-6

Home work #5

5. A jet airplane has the TA and TR curves in fig. 2-1.  The airplane data: weight = 12,000 lb. standard sea level day; clean configuration. Find:

a.   Vmax at 95%

b.   V for maximum climb angle 95% (RPM)

c.   sine of maximum climb angle (100% RPM)

d.   Rate of climb at 300 knots (95% RPM)

e.   V for best endurance;

f.    V for maximum range;

g.   V for maximum range with 100 knots of headwind.

h.   The value of L/D max  Home work #6

3.       How much horsepower does it take to climb a 4000 pound airplane through a 1980 foot change in altitude in one minute? 4.       In a power off glide at 78 knots, the drag is 200 pounds. In a 2450 pound aircraft, what is the rate of descent? 5.       If 500 pounds of thrust results in 200 knots TAS, what is the thrust horsepower?

What is the brake horsepower assuming 88% propeller efficiency? 6.       At 5500 ft density altitude and 55% Power, a B-19 consumes 6.7 gallons per hour in order to generate 84 knots true airspeed. What is the specific range? 7.       A Travel Air uses 16 gallons per hour to generate 234HP. What is the specific fuel consumption? 11. Using figure 2-2 Calculate the velocity for best range with a 100kt headwind for the airplane at 12,000 and 8,000 lb gross weight.  15.     Using the PA-PR curves in 2-3 for a propeller airplane find: (Assume a 10,000-lb weight)

a. Vmax

b. sine of the climb angle at Vs

c. sine of the climb angle at L/D max

d. rate of climb at Vs

e. rate of climb at 300 knots

f. velocity for maximum endurance

g. velocity for maximum range

h. velocity for maximum range with 100 knots headwind  19. A Beech Baron 55 has a published sea level power of 520 HP. At 10,000 feet with 70% cruise power set, the fuel flow is 30 gallons per hour and the TAS is 200 knots.

What is the specific fuel consumption?_______

What is the Specific range?________ 22. How much brake horsepower does it take to cruise an airplane under the following conditions?

Drag = 600 lbs

IAS = 200 kts

Density ratio = ..7385

Propeller efficiency = 80% 23. It requires 525 pounds of thrust to hold 200 knots EAS at sea level. How much thrust would it take to hold the same EAS at 15,000 feet?

hint: in balanced flight drag equals thrust required +