Asci 309 Ex. 1

ASCI 309 Exercise 1

Gross weight ………………… = 100,000 lbs.

Average drag………………… = 5,000 lbs.

Average friction force………. = 1,000lbs.

Average thrust………………. = 34,000lbs.

Lift off speed………………… = 150ktas

Compute the acceleration on the aircraft during takeoff.

W=mg

m=100,00032.2

m=3106slugs

a=Fm

a=T-d-Fm

a=34,000-5,000-1,0003106slugs

a=9.01ft/s2

What would be the length of the takeoff run?

a=9.01ft/s2

Vf=150*1.69=253.5ft/s

V=at

Va=t

T=(253.5)/(32.2)=7.87s

t=7.87s

D=12at2

D={129.017.87)2=279

D=279ft

How long will it take until liftoff once the takeoff roll is started?

V=Vο+at

150ktas=7.87s

t=(150*1.69)/7.87

t=32.2s

Determine how fast this airplane should be going when it passes the 2,000 foot runway marker.

s=(V2-V02)/2a

V=2as=2*9.01*2000=189.84ft/s

189.84ft/s=112.5knots

What is the power (HP) of the aircraft engines after takeoff at Average Thrust at 250KTAS?

HP=T*Vk325=TVk325

HP=34,000lbs*250ktas=26,153.4

HP=26,153.8

What is the Kinetic Energy of the aircraft after climbing out at 250KTAS with a new weight of 95,000lbs?

KE=12mV2

12(95,000/32.2)(250*1.69)2=2.63x108

KE=2.63x108ft/lbs

What is the Potential Energy of the aircraft after climbing out to 10,000 ft above sea level with the new weight of 95,000lbs?

PE=Wh

95,000*10,000=9.5x108

PE=9.5x108ft/lbs

What is the angle of climb (deg) for an airplane at 250KTAS with a climb rate of 4,000ft/min?

4,000ft/60s= 66.67ft/s

250KTAS=422ft/s

AOC=8.98°