Hi!

Could anyone give me a hand with this navegation problem?
It says: An airplane takes 2,4 statue miles in 47 seconds. What will it be his Ground speed?
a) 131 Kts
b) 209 Kts
c) 183 Kts
d) 160 Kts

Cheers!

160kt

Convert distance to Nm first

Hi, I know the answer is 160, but i am asking explanation!

1 - Convert statute miles into nautical miles (2.0855)

2 - Take this answer and divide by 47 to get distance travelled in 1 second

3 - Multiply this answer by 60 to get distance travelled in 1 minute

4 - Multiply this answer by 60 to get distance travelled in 1 hour

The distance travelled in one hour is your groundspeed. Groundspeed is in knots (nautical miles per hour).

Try to keep as many decimal places in each stage of the calculations. (So use all of the numbers after 2.0855 in my example above). This will improve the accuracy of the answer.

Sometimes the exam is written to catch you out if you 'round' your calculated figures too early.

2.4 statute miles = 2.1 nautical miles
2.1 nautical miles in 47 seconds means 160 nautical miles in 3600 seconds, i.e., one hour (2.1*3600/47).
(please yourself with more precise rounding -- Edit: taking the exact number gives 159.744 knots, the 2.1 approximation gives 160.851 knots, so no spectacular difference in this case)

Also keep in mind that if this is for the PPL exam then you should be doing this conversion/calculation on a CRP1 / CRP5 computer not an electronic pocket calc.

Distance x 60 / time

2.08 x 60 / .78 (47 as a decimal of a minute) = 160

Thank you!

hi, i;ve got another doubt if someone could please explain me how to solve it.

Magnetic heading 311º
drift 10ºL
Relative dialing of NDB: 270º
whats the magnetic dialing of NDB received from the plane?
a) 130º
b) 212º
c) 221º
d) 206º

the anwer is C, thank you.

Heading is 311M

Adding 270 relative beaing gives 311M + 270 = 581M

All bearings and headings must be between 0 degrees and 360 degrees.

581M is greater than 360 so subtract 360 to get 581M - 360 = 221M

Thank you!

Also keep in mind that if this is for the PPL exam then you should be doing this conversion/calculation on a CRP1 / CRP5 computer not an electronic pocket calc.
Why? I believe you can take a non-scientific calculator into the exam (JAA).

Probably worth mentioning the base formula for the first question is

Speed = Distance / Time

Could someone help me with this one now?

Gross weight= 4750kg
GC station= 115,8
What will be the new position of the CG if we move 100kg from station 30 to station 120?

Answer 117,69


Thank you guys!

arm = moment/weight

You are increasing the moment by 100 x (120 - 30) = 9000 but you are not changing the weight, so the extra arm is 9000/4750 = 1.89

115.8 + 1.89 = 117.69

Hi,

Could someone tell me if I am wrong or the test is incorrect?

Distance 520 NM. Time 02:10. Find the speed

a)245kts
b)250kts
c)240kts
d)235kts

Is giving me answer c but the test correction marks d for answer.

Cheers again!