View Full Version : Another Mass&Balance Q
Q. The loaded mass of an aircraft is 12400kg. The aft CG limit is 102 in. aft of the datum. If the CG as loaded is 104.5 in. aft of the datum, how many rows forward must two passengers move from the rear seat row (224 in. aft) to bring the Cg on to the aft limit, if the seat pitch is 33 in. Assume a passenger mass of 75kg each?
A. 7 rows
Any help on this.
From post 7
"A picture is worth a thousand words"
This is very basic maths! If you get stumped by a question like this, ALWAYS sketch it out!
The actual answer is 6.26 rows.
This is what I did
12400*2.5=31000 150*33=4950
12400/4950=6.26
The answer seems a bit too far out from 7 given by the book.
Mad (Flt) Scientist
8th Aug 2008, 21:34
This is what I did
12400*2.5=31000 150*33=4950
12400/4950=6.26
The answer seems a bit too far out from 7 given by the book.
If they move 6 rows, they are 0.26 rows "short" - so you'd still be outside the limits.
6.26 is the MINIMUM amount they must move in fractional rows. But seats come in integer rows - unless on a certain recent flight from SFO. :)
So if you must move a bit more than six, the minimum you actually must move is seven.