Hi

I am going through the practice exams, and I am having an issue with one of the answers. I think the worked solution is wrong. If you take the 'correct' answer of 123 Kg and apply zero fuel weight, you find that the CG is out.

Refer VFR (Day) Booklet Loading System CHARLIE page 14/15.Given:

Aircraft empty weight 689 kg; Empty aircraft index units = 19522; Oil = 7 kg; Row 1: pilot and passenger = 110 kg; Baggage (baggage compartment) = 75 kg; Fuel 140 litres

The maximum passenger weight, in kg, that may be carried in Row 2 at take-off is closest to - 93 KG, 123 KG, 135 Kg, 154 Kg.

For 123 KG in row 2, I found:
Full Fuel: 1103 KG and 33139.1 IU with an ARM of 3004.45.
Zero Fuel: 1004 KG and 30218.6 IU with an ARM of 3009.82

The zero fuel ARM is too far to the right on the graph

For 94 KG in row 2, I found:
Full Fuel: 1074 kg and 32122.1 with an ARM of 2990.1
Zero Fuel: 975 kg and 29201.6 with an ARM of 2995.0

It is less than obvious which is closer, so I then looked at a weight of 108.5 kg, half way between the two answers

For 108.5 KG in row 2, I found:
Full Fuel: 1088.5 kg and 32617.1 IU with an ARM of 2996.5
Zero Fuel: 989.5 kg and 29696.6 IU with an ARM of 3001.2

This then suggests that 123 KG is actually closer to the correct answer, but it does give a CG which is out of bounds and therefore is not acceptable. What is worse, from my point of view, the worked solution does not attempt to calculate the CG at zero fuel with the proposed 123 KG baggage.

Or have I totally missed something?

Thanks

Darryl

Hi Daryl,

Thanks for bringing that question to our attention. There were indeed problems with it! I have corrected the working and added the correct answer option which was missing in the original version. Got to love those brain f@rts

Cheers,

Rich

Hi Richard

Can you please post the actual correct workings to this question (given you have fixed it up) including the plotted graph please?

That would be tremendously helpful, as there seems to be various answers floating around on this one.

Regards
Simon.

Hi Simon,

So we don't spoil the question for others working through the Exam Preps, I have sent you a PM with the solution as a PDF attachment.

Cheers,

Rich