Nav Questions help !!
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Nav Questions help !!
Hello Aviators,
Please help me to solve few Nav Questions. I am preparing for the DGCA CPL Exams. I have a answers, but not able to solve the given questions.
Q1. F/L 350, TAT -11 C, Temp dev from ISA +20, Find out OAT & TAS?
Answer : OAT - 35 & TAS = 490
Q2. F/L 350, TAS 450 K, TAT -11C, Find the Temp dev from ISA?
Answer : +24 Degree C
Q3. On a Cross country you are flying on Magnetic Track of 090, Var is 2 W, The Flt level to fly is ?
Answer : 75
Q4. Earth Convergency btw two points 8 deg long apart is 7.2 deg on the same parallel of lat P is 173W & Q is 176 E Find.
a) G/C bearing of P from Q in NH
b) G/C bearing of Q from P in SH
Answer : 085 & 265
Thanks
Please help me to solve few Nav Questions. I am preparing for the DGCA CPL Exams. I have a answers, but not able to solve the given questions.
Q1. F/L 350, TAT -11 C, Temp dev from ISA +20, Find out OAT & TAS?
Answer : OAT - 35 & TAS = 490
Q2. F/L 350, TAS 450 K, TAT -11C, Find the Temp dev from ISA?
Answer : +24 Degree C
Q3. On a Cross country you are flying on Magnetic Track of 090, Var is 2 W, The Flt level to fly is ?
Answer : 75
Q4. Earth Convergency btw two points 8 deg long apart is 7.2 deg on the same parallel of lat P is 173W & Q is 176 E Find.
a) G/C bearing of P from Q in NH
b) G/C bearing of Q from P in SH
Answer : 085 & 265
Thanks
Join Date: Jul 2010
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Q1. F/L 350, TAT -11 C, Temp dev from ISA +20, Find out OAT & TAS?
In ISA temp at FL 360 = -56.5 C and lapse rate = 2 C/ 1000 ft.
So temp at FL 350 in ISA = -56.5 + 2 = -54.5 C
Temp deviation = ISA + 20
Therefore temp at FL 350 (OAT) = -54.5 + 20 = -34.5 C
OAT = TAT - (TAS/100)^2
-34.5 = -11 - (TAS/100)^2
23.5 = (TAS/100)^2
TAS = 485 kts.
In ISA temp at FL 360 = -56.5 C and lapse rate = 2 C/ 1000 ft.
So temp at FL 350 in ISA = -56.5 + 2 = -54.5 C
Temp deviation = ISA + 20
Therefore temp at FL 350 (OAT) = -54.5 + 20 = -34.5 C
OAT = TAT - (TAS/100)^2
-34.5 = -11 - (TAS/100)^2
23.5 = (TAS/100)^2
TAS = 485 kts.
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Q2. F/L 350, TAS 450 K, TAT -11C, Find the Temp dev from ISA?
OAT = TAT - (TAS/100)^2
OAT = -11 - (450/100)^2 = -11 - 20.3 = -31.3 C
Temp at Fl 350 in ISA = -54.5 C
So OAT at FL 350 is warmer than that in ISA
Therefore Temp deviation = + (54.5-31.3) = + 23.3 C
OAT = TAT - (TAS/100)^2
OAT = -11 - (450/100)^2 = -11 - 20.3 = -31.3 C
Temp at Fl 350 in ISA = -54.5 C
So OAT at FL 350 is warmer than that in ISA
Therefore Temp deviation = + (54.5-31.3) = + 23.3 C
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Q4. Earth Convergency btw two points 8 deg long apart is 7.2 deg on the same parallel of lat P is 173W & Q is 176 E Find.
a) G/C bearing of P from Q in NH
b) G/C bearing of Q from P in SH
Convergency = d.long x Sin Lat
7.2 = 8 x Sin Lat
Sin Lat = 0.9
Lat = Sin inverse 0.9 = 64*10'
d.long between P and Q = 11 deg
Convergency = 11 x 0.9 = 9.9 deg
Conversion angle = 5 deg approx
GC is near to the pole and RL is near to the equator (GC curved concave to the equator).
a) In Northern Hemisphere
RL bearing of P from Q = 090
GC bearing = RL - CA = 090 - 5 = 085
b) In Southern Hemisphere
RL bearing of Q from P = 270
GC bearing = RL - CA = 270 - 5 = 265
a) G/C bearing of P from Q in NH
b) G/C bearing of Q from P in SH
Convergency = d.long x Sin Lat
7.2 = 8 x Sin Lat
Sin Lat = 0.9
Lat = Sin inverse 0.9 = 64*10'
d.long between P and Q = 11 deg
Convergency = 11 x 0.9 = 9.9 deg
Conversion angle = 5 deg approx
GC is near to the pole and RL is near to the equator (GC curved concave to the equator).
a) In Northern Hemisphere
RL bearing of P from Q = 090
GC bearing = RL - CA = 090 - 5 = 085
b) In Southern Hemisphere
RL bearing of Q from P = 270
GC bearing = RL - CA = 270 - 5 = 265
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April 2012 Session
@ginaviator
This is a great thread, we should keep it open for nav questions....
@gAMbl3
Great explanations, thanks for helping....
Sorry to side track, But can anyone speculate when will the April 2012 session exams happen & also, does anyone know when does the online portal opens for filling DGCA forms online.
I am trying to plan my travel but it is very hard without knowing the dates....
This is a great thread, we should keep it open for nav questions....
@gAMbl3
Great explanations, thanks for helping....
Sorry to side track, But can anyone speculate when will the April 2012 session exams happen & also, does anyone know when does the online portal opens for filling DGCA forms online.
I am trying to plan my travel but it is very hard without knowing the dates....
