Wed Apr 23, 2008 4:18 pm
#593785
I'm currently revising for my air law exam by taking the Air Quiz online exams to highlight gaps in my knowledge. However, there is one question on temperature effects on altimeters which either Im not understanding right, or the air quiz answer is wrong.
The question is
Which of the following statements concerning altimeters is true?
A In air colder than ISA, an altimeter will under-read the true altitude
B In air colder than ISA, an altimeter will over-read the true altitude
C In air hotter than ISA, an altimeter will over-read the true altitude
D Normal temperature variations do not affect altimeter accuracy
My logic is, colder air = denser = higher pressure. The effect of this is that the altimeter thinks it is at a lower altitude (where it would normally be that higher pressure). The altimeter is therefore under-reading the true altitude. You are flying higher than what is being indicated.
The air quiz answer is telling me it is B, the altimeter is over-reading the true altitude.
Am I right or is Air Quiz right?
If I am wrong, can someone please correct my logic so I have it square in my head!
Thanks
Mark
The question is
Which of the following statements concerning altimeters is true?
A In air colder than ISA, an altimeter will under-read the true altitude
B In air colder than ISA, an altimeter will over-read the true altitude
C In air hotter than ISA, an altimeter will over-read the true altitude
D Normal temperature variations do not affect altimeter accuracy
My logic is, colder air = denser = higher pressure. The effect of this is that the altimeter thinks it is at a lower altitude (where it would normally be that higher pressure). The altimeter is therefore under-reading the true altitude. You are flying higher than what is being indicated.
The air quiz answer is telling me it is B, the altimeter is over-reading the true altitude.
Am I right or is Air Quiz right?
If I am wrong, can someone please correct my logic so I have it square in my head!
Thanks
Mark