Hi there,

This is a question in regards to the latest PPL book page 1.3.12, drill exercises, question 1; Loading system Alpha.

You having indicated in question 1 that the fuel on board at take off is 197 litres. Yet in the answer, you have input it as 140kg. There is no mention anywhere of how you worked this out (unless I missed it?) and I'm curious if the actually exam itself will address this unknown factor (which a google search tells me is 0.72 or 0.71 depending on who you read.)

Is this a known omission in the book, or is it deliberate and does anyone know how this factor will translate in the exam? Will CASA tell me or do I just need to know this by memory and if so, is it 0.71 or 0.72?

Thanks again everyone.
M

Gidday Matt

For many years, CASA used .71 for the specific gravity of AVGAS. That has changed some time ago to .72. In fact if you check CASA's conversion factors in the ERSA CON section, you will find that they have used .72. So you can be confident that .72 is the go. What has happened here is the answer to the question was worked years ago when the figure was accepted to be .71.

Don't stress too much about the 2kg, there is no way the answer choices in the exam will be anything like that close together and the question always includes the phrase 'is closest to'. In fact, since AVGAS is actually a mixture, the actual specific gravity varies slightly from batch to batch.

Also it is interesting to note that, since a litre is a unit of volume, the actual mass of fluid in a litre changes with temperature. There is a little more fuel in a litre on a cold day than there is on a hot day due to the expansion caused by temperature rise.

Bob

Thanks Bob.

Just got another quick question regarding LS Charlie.

In the book the questions in the quizzie (#13) you are asking us to compute some answers using the arm, but the arm values are not supplied. Is this what it will be like in the exam or do I need to memorise all the arm values as 2750 for Row 1, 3600 for row 2, 2950 for Fuel etc...? Or are they supplied somewhere?

Thanks again, looking forward to finishing this chapter I tell you!

M

Hi Matt,

The arms are listed on page 15 of the Training & Examination Workbook (formerly known as the VFR (Day) Work Booklet). You will be given access to a copy of this booklet when you sit the exam. A current copy can be found here:

www.casa.gov.au/wcmswr/_assets/main/fcl/...yberexam/day_vfr.pdf

Just be aware there are a few errors in that publication which we talk about in this forum thread:

www.bobtait.com.au/forum/important-news/...in-casa-vfr-workbook

Cheers,

Rich

Perfect! CASA making it easy for me, haha

Cheers,
M