K.Haroon Site Admin
Joined: 11 Dec 2005 Posts: 1311

Posted: Sat Apr 21, 2012 6:42 pm Post subject: Question on MEP Graphs 


(Refer to CAP 598 or figure 032_ 32)Given:OAT: 25oC Pressure Altitude: 3000 ft RWY: 26L Wind: 310o/20 kts Take off mass: 4400 lbs Heavy duty brakes installed Other conditions as associated in the header of the chart Find the AccelerateStop distance:
a) 3550 ft < Correct
b) 3800 ft
Due to Heavy duty brakes installed the the ASD that comes out from the graph has to be reduced by 7% as mentioned in the note on the graph.
(Refer to CAP 698 or figure 032_31)Given:OAT: 24oC Pressure Altitude: 3000 ft RWY: 080o/12 kts Take off Mass: 3800 lbs Other conditions as associated in the header of the graph.What is the ground roll?
a) 1050 ft
b) 1700 ft
c) 1350 ft < Correct
d) 1150 ft
Straight Forward. However Runway direction is missing in the question. It is RWY 12.
(Refer to CAP 698 or figure 032_31)Given:OAT: 24oC Pressure Altitude: 3000 ft RWY: 30R Wind: 060o/4 kts Take off Mass: 3800 lbs Other conditions as associated in the header of the graph.What is the take off distance over a 50 ft obstacle?
a) 2150 ft
b) 1670 ft
c) 1550 ft
d) 2000 ft < Correct
In my workout it comes close to 2030
For the same data the Ground roll is?
a) 2150 ft
b) 2000 ft
c) 1780 ft
d) 1670 ft < Correct
In my workout it comes close to 1700
Straight forward BUT!!  YOU REALLY HAVE TO BE PRECISE IN THIS ONE as the wrong answers are very close.
(Refer to CAP 698 or figure 032_37) Given:OAT: 0 deg C Pressure Altitude: 18000 ft Gross Mass: 3750 lbs Mixture: leaned to 25oF G rich of peak EGT. Other conditions as associated in the header of the graph What is the two engine rate of climb?
a) 1050 ft/min < Correct
b) 870 ft/min
c) 1370 ft/min
d) 550 ft/min
The above mentioned part of the graph is the trick.
There are 3 weights mentioned in the graph 3500, 4000 and 4750 lbs and 6 lines.
Each weight has two lines and each weight is written between its two lines.
For e.g. 3550lb has two lines (yellow ones). The long one is for a rich mixture and the short one for a lean mixture.
In the question the weight is 3750 and the mixture is lean.
So interpolation is required bewteen short lines (which represent lean mixture).
The first short line is 3500 (yellow) and the next short line is 4000 (blue).
So 3750 will be between them.
It is by chance the the long 3500 lb line coincides with our interpolated 3750lb line.
Drop down to get the answer.
Note: The lines are not coloured in the actual graph 
