Thread: V-n Diagrams
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Old August 26th 04, 03:25 PM
Mike Rapoport
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The load limit for normal catagory isn't always 3.8G. In a 747 it is around
2G and a MU-2 is 3.25G.

Mike
MU-2


"Bob Moore" wrote in message
. 6...
john smith wrote

The one item for the PA32-300 that would not follow the formula for
calculating the lift line was Va. The book shows it as 132 kias, but
the formula generates a speed of 103 kias for the intercept of the
3.8 load limit line.


When is 3.8g not 3.8g? When it is 4.5g or some other number.
Remember, 3.8g is a minimum figure for the normal category.
I have seen V-N diagrams for aircraft where the 3.8g line was
extended upward to accomodate the gust loading envelope at Vno.
Observe the gust envelope in the diagram at this web site:
http://adg.stanford.edu/aa241/structures/vn.html


It is interesting to note that Piper does not allow any negative
maneuvers in the Normal catagory, on 3.8 positive.


This is contrary to the required limits in FAR 23

Bob Moore