1. An aircraft is flying with wing loading of 50 and maximum CL as 2.4. If density is 1.225 then, find the stall speed of the aircraft.
a) 5.832m/s
b) 5.823
c) 5.632m/s
d) 5.632
Explanation: Given wing loading W/S = 50, maximum CL = 2.4, density ρ = 1.225
Now, stall speed of aircraft is given by,
Vstall = \(\sqrt{2*(\frac{W}{S})(\rho*CL)} = \sqrt{2*(50)/(1.225*2.4)} = \sqrt{34.01}\) = 5.832m/s
2. A civil A/C has maximum lift coefficient of 3. If wing loading is 120 then, find approach speed of the aircraft. Consider sea-level density.
a) 10.5m/s
b) 10.50km/s
c) 12
d) 120
Explanation: Given, civil aircraft, maximum CL = 3, wing loading W/S = 120
Approach speed of civil aircraft is given by,
Va = 1.3*Vstall
Where, Vstall = \(\sqrt{2*(\frac{W}{S})/(ρ*CL)}
= \sqrt{2*(120)/(1.225*3)}\) = 8.08m/s
Now, Va = 1.3*Vstall = 1.3*8.08 = 10.5m/s.
3. Determine wing loading for civil aircraft if lift-off speed is 80m/s and maximum lift coefficient is 2.8.
a) 9071.07
b) 9111
c) 911
d) 91
Explanation: Given, a civil aircraft.
Lift off speed V1 = 80m/s, maximum lift coefficient CL=2.8.
Wing loading is given by,
W/S = 0.5*ρ*V2*CL
Where, V = V1/1.1 = 80/1.1=72.72m/s
Hence, wing loading is given by,
W/S = 0.5*ρ*V2*CL
W/S = 0.5*1.225*72.722*2.8 = 9071.07.
4. Which of the following is correct for a jet aircraft take-off parameter (TOP)?
a) TOP = \(\frac{W/S}{σCL \frac{T}{W}}\)
b) TOP = \(\frac{1}{σCL \frac{T}{W}}\)
c) TOP = \(\frac{2}{σCL \frac{T}{W}}\)
d) TOP = \(\frac{W}{σCL \frac{T}{W}}\)
Explanation: Take-off parameter is used to determine take-off distance for the aircraft. TOP is affected by wing loading and thrust loading both. Hence, proper estimation of such parameters are crucial. TOP for jet and prop driven will be different.
For jet, TOP = \(\frac{W/S}{σCL \frac{T}{W}}\).
5. An aircraft has catapult end speed of 30m/s and wind over deck as 20m/s. If maximum CL is 2.6 and density is 1.22 then, find catapult wing loading.
a) 3276.859
b) 327
c) 32
d) 2
Explanation:Given, maximum CL = 2.6, density ρ=1.22
Catapult end speed Ve = 30m/s, wind over deck Vwod = 20m/s
Now, catapult wing loading is given by,
W/S = 0.5*ρ*(Ve+Vwod)2*CL
W/S = 0.5*1.22*(30+20)2*2.6
W/s = 3276.859
6. For prop aircraft at maximum range what will be the wing loading. Given CD0=0.02, aspect ratio as 8, e=0.6 and q=39.20Pa.
a) 21.5
b) 12.5
c) 1.05
d) 25
Explanation: Given CD0=0.02, AR =8, e=0.6, q=39.20Pa.
For maximum range wing loading is given by,
W/S = \(q*\sqrt{\pi eARCD0} = 39.2*\sqrt{\pi*0.6*8*0.02}\) = 21.5.
7. Jet aircraft with CD=0.01+0.02CL2 is performing loiter. Find wing loading for maximum loiter if, AR=8.5, e=0.7 and dynamic pressure is 25Pa.
a) 10.80
b) 11.80
c) 12.80
d) 13.08
Explanation: Given, CD = 0.01+0.2CL2, AR=8.5, e=0.7, Dynamic pressure q=25Pa.
From CD = 0.01+0.2CL2, CD0 = 0.01.
Wing loading for maximum loiter is given by,
W/S = \(q*\sqrt{\pi eARCD0}\) = W/S = 25*\(\sqrt{\pi*0.7*8.5*0.01}\) = 10.80
8. A prop driven A/C has BHP/W as 0.08. If density ratio is 0.2 and take off lift coefficient is 3 then find take-off parameter for the aircraft. Given wing loading W/s = 35.
a) 700
b) 800
c) 900
d) 500
Explanation: Given, a prop Aircraft.
BHP/E = 0.08, density ratio σ = 0.2, CL at take-off = 3.
Take-off parameter TOP = \(\frac{W/S}{σCL BHP/W}\) = 35 / (0.2*3*0.08) = 700.
9. Process of determining the take-off gross weight and required fuel weight is called as ________
a) aircraft sizing
b) aircraft Lofting
c) aircraft drafting
d) aircraft drawing
Explanation: Aircraft sizing is nothing but the process of estimating and evaluating the total weight of an aircraft. The weight will be estimated based on requirements, specifications, fuel requirements etc. lofting is mathematical modelling of the skin.
10. We can provide sizing based on new design only.
a) True
b) False
Explanation: Aircraft sizing is process of weight determination based on different performance parameters. Aircraft can be sized in two different way; either using new design or using existing design of engine which meet all the required parameters.