MET ATPL UNSOLVED QUESTIONS

[david_320200]

Hi everyone. I am starting this thread to put up Met Questions which either are incorrectly answered in Oxford books or may be i am unaware of the correct approach to solve them. Either case i would like to request everyone who are in a better state of knowledge than me to reply with a solution.

I would keep adding the questions as i come across them.

Thankyou all for your valuable time!

Here we go,

1) At a certain position, the temperature on the 300 hPa chart is -48°C; according to the tropopause chart, the tropopause is at FL 330. What is the most likely temperature at FL 350?

a. -54°C b. -50°C c. -56.5°C d. -58°C . coorect ans is (a)

[LieDetector]

There is a thread for ATPL exams, use the search function.

[aviatros]

go for this met forum

http://www.pprune.org/professional-p...questions.html

[St_Elmo]

1) At a certain position, the temperature on the 300 hPa chart is -48°C; according to the tropopause chart, the tropopause is at FL 330. What is the most likely temperature at FL 350?

300 hPa corresponds to FL300 approx
Temp at FL300 = -48 Deg C
Temp at FL330 = -48 Deg C + (2(30-33)) Std ISA Lapse Rate = -54 Deg C

Tropopause begins at FL330. thus, temperature at FL350 = -54 Deg C

[david_320200]

Thankyou for the quick solution. I could not assimilate the fact that the Temp at Tropopause could also be higher or lower than -56.5. I was doing it the other way around. EYES OPENED UP NOW!!

[david_320200]

2) Which of the following is true? QNH is:

a. Always more than 1013.25 hPa
b. Always less than 1013.25 hPa
c. Never 1013.25 hPa
d. Can never be above or below 1013 hPa

Ans C. (i think all of them are incorrect) can anyone explain .?

[david_320200]

You fly over the sea at FL 90, your true altitude is 9100 ft and QNH is unknown. What can be said about the atmosphere temperature?

a. QNH is lower than standard
b. It is colder than ISA
c. It is warmer than ISA
d. Nothing, insufficient information.

Ans is D. How and why? Is it because Altitude on QNH and ISA Deviation both are unknown?

[St_Elmo]

Re-phrased answer:-
2) Which of the following is true? QNH is:
a. Always more than 1013.25 hPa
b. Always less than 1013.25 hPa
c. QNH can be lower as well as higher than 1013.25 hPa
d. Can never be above or below 1013 hPa

Voilà that is the answer to your next question. Flight levels are wrt 1013.25. Local pressure altitude wrt to QNH is not given and as QNH can be lower as well as higher than 1013.25 hPa. Thus, d. Nothing, insufficient information

[Halfwayback]

David

Welcome to Pprune.

You have had some of your questions answered here already but these are generic questions that you should be asking of your ground instructor and not just posting here which is a forum for specific SE Asia discussions.

I am closing the thread.

HWB