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AE-445
(Test #3)
Open Books and Open Notes. Laptops allowed.
April 21, 2025
Name: ....................... .
Please show your work!!
Give the equation number or the figure number that you use in your calculations.
(36 Pts)
Q. l A glider weighs 1200 lbs and has a wing loading of 11 lbs/ft2. Its drag polar is:
Co= 0.015+ 0.03CL2
Asswne that the glider is launched at 3000 ft (use the information in standard atmosphere
at this altitude) in still air and over level ground.
Calculate the following:
a) The greatest distance it can cover along the ground.
b) The speed for the greatest distance it can cover along the ground.
c) The longest duration it can stay airborne.
d) The speed for the longest duration it can stay airborne.
e) The minimum flight path angle.
f) The minimum rate of descent.
Assume that the effects of changing density is neglected
:::= l ~ o 1.5. o.03 -=o,o~zq
c) +ml\)( ~ R. Dm,n """"? ( LL~/c. 0 2 )rn~ ~
( Ct. 3/co' )m• x -- 3A Ae. ' ~ - 3/o.c., 3 { 3/o-03 _ ~lo.~ l
IG:, ~-z;:- -/<, 0.015
RDm,n :: '\{ ~ 1:. (co~ -) ~ z. (.//
~ 5 17 Cl m,,, l/ 2.nc·-a, (S10, 31Y' -:: L./.LJS .5
{ry,t._ x :: h/Rom ,n -= 3
000
/LJ.l) s -) G7 3. ~ Sec./
d) C1-@ c'-1/co-imi:-x - V3r-/le.·C.o~ - l.'2 2
Ve,~ l:.fYJIAX -:: {l?Ee c,3/co 1. . -= 2.~ ~-1/ ,. ,, - 90. 'D7 n/5
-f') Prom pew-I- c) }Rom,r1 ~ 4. 45 ({js ]
(IO Pts)
0- 2 The stallin~ speed of an aircraft is I 00 mph.
a) Esh mate the approach speed of this aircraft?
~
b) Estimate the take-off speed ofthfa aircraft?
=-J t 3 o fY'i ph
~) Vapp,calh _/ ,3 vs-1~ 11
-=- fJ_--Zo VY"\ l') "1
6) Vf:o -= ) 2 v.s+ '- II
(28 pts)
Q.3
A jet powered aircraft has the following characteristics:
• W = 15,000 lbs.
2
• Wing loading of 50 lb/ft
2
• Co= 0,015 + 0.6CL
• M= 0.3
• Elliptical wing planform
level conditions.
The above aircraft is flying straight and level at standard sea
Calculate the following:
a) CL
b) Co
c) Using the analytical procedures calculate the following:
1) maximum level speed.
2) What is the CuCo of this aircraft at maximum speed
fl-;;. 0, () 0 2. 3 .)lu j / {{ 5
V£A ~ I, II"'· l-1 fl/ ) ===)
q- 1~3 . 3 105 / ft -z.
°') L -: w --:: r5u u0 lb. )
CL -:: L
-
:[u
~ /773 7 5 J
r-s I 33-32-
6) lp 7.. 0,0 15 1 Q.6 ll.,
1
-= I o.a9Ci l
)]
CJ VrV )v.X ~1 Tu ,11 2 (+!
-
CL /er:> -- 0.3 7S1 /0 ,(!Jqq - ,~ 7 4
-7
•
(16 pts)
• 2
Q.4 mass of 300ankg, an~ wmg
A glider has a If refere ~ce ~ea of 14 m , and is flying at standard
sea level conditions. CL= 0.
9' d Co - 0.035 for th1s ghder, calculate:
a) Glide angle.
b) Speed.
,.----
c) Rate of descent.
f "" -{M - ' ( cole L ) -= / ;: z 3, 0 J
'~-: z 3c,o q 1;; -= ftcr' 52 f'fJ/5)
'~ F' - • i.ZZ 5•/' -{·0 ·q
- /q, 52 •~/ n2 .Z3 °:: ..
s]
/-~ -.--:J-_0_m_J__
(IO pts)
Q.5 The following information is known about an aircraft :
a= 12°
y=40
V,,,= 250m ph
Calculate the following:
a) The rate of climb
b) The pitch attitude angle
o-) Re= VC10 Jin y - /17. 'i4 mp h]
b) = 6 - I -I o< - LJ 1/2 -=-@
