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## Climb Weight limits

• Alex Alpine
• Topic Author

### Alex Alpine created the topic: Climb Weight limits

Hello, in page 37 of the CFPA CPL booklet it discusses climb weight and how you compare drawing the line throughout the entire chart (line B ) versus drawing a line against the climb weight limit reference line (line A) and you choose the lesser of the two. Just to confirm, line A is outside the diagonal part of the climb weight limit reference line, do you just continue vertically if you hit the horizontal part of the reference line?

Picture included!

Hopefully this makes sense, Thanks!
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• John.Heddles
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• ATPL/consulting aero engineer
• Posts: 876

### John.Heddles replied the topic: Climb Weight limits

drawing the line throughout the entire chart

This establishes the field length limited TOW.

drawing a line against the climb weight limit reference line

This establishes the climb weight limited TOW.

The two have nothing to do with each other. They are quite different limits for the calculation exercise. You have to comply with both requirements, so you are limited by whichever is the lower value.

That they are drawn on the one sheet is a simple matter of convenience and saving real estate. As you review various format charts over your career in flying, you will observe that there are various ways to draw climb limits.

line A is outside the diagonal part of the climb weight limit reference line, do you just continue vertically if you hit the horizontal part of the reference line?

Correct. You still need to run both the field length limited and climb weight limited calculations. If your entry line hits the climb line in the horizontal section, that just means that the climb limit is greater than the MTOW and, hence, you truncate the climb limited calculation at the MTOW case. Strictly, you are still comparing the two limits. However, effectively, the climb limited weight is irrelevant as it is greater than MTOW which becomes your effective climb limit. Then, if the field length limit is less than MTOW, you restrict the operation to that weight.

Engineering specialist in aircraft performance and weight control.