Hi PaulGa,

Check in the AIP, ENR 1.2 - 1 Para 1.1.3

1.1.3 For pilots not authorised to fly at night, it is recommended that
they plan to arrive at the later of the destination aerodrome or
alternate aerodrome at least 10 minutes before last light
(allowing for any required holding).

So if you are planning to allow an extra 10 minutes for a circuit, you should allow 20 minutes in total before Last Light.

Cheers W

Thanks Wayne…appreciate your reply clarifying that. I am doing the exam Monday so trying to iron out grey areas. Apologies for all of the questions but with home study, I am having to work backwards from the answers to questions and search for where/what i have got wrong.
Is it possible to check 2 more for me please.
1. Q39 of the same test had an answer of 61g. It appears the answer had 10.2G for the hold at Charlie which i think should be 7.5. Can you check this and let me know if this is correct or how the 10.2 is calculated ?
2. Q40. When fuel is burnt from auxiliaries i understand that it stays within the envelope. I did another practice exam and got it wrong with this answer…they did mention 2360kg in the question which Bob covers in the text. If that question pops up in the exam what would you suggest the answer is if they don’t mention weight ?
On top of chart accuracy and rounding this subject is a challenging one when you’re 50. ????
Thanks again,
Paul

Paul,

Q39 - 30 minutes of holding for weather is at holding rate required of 15 gph is 7.5 gals. You are correct, so there is an error in the book. Minimum fuel is 24.3 x 1.1 + 15 + 3 + 6.2 + 7.5 = 58.43 gal.

Q40 - As the aux fuel is used, the C of G moves forward. The forward limit moves forward at a faster rate as the weight changes. This is a design feature to ensure that the aircraft stays in balance as fuel is burnt. At a weight of 2360kg, the forward limit of C of G stops moving and it is doubtful that there would be any fuel remaining in the Aux tanks.

Decimal points and accuracy is a big discussion within each class. CASA recommends on their website that decimal points are kept throughout the calculation with a final rounding to an appropriate whole number at the end. As most exam questions now require the entry of a whole number, one hopes there is a small leeway for the answer

Cheers Wayne

Thanks Wayne

Hello Wayne,

Last one for the day I promise....With this question from the Practice Tests. I was hoping to clarify why the load couldn't be rearranged. Most questions state load not to be changed etc.... As this question didn't I assumed you could shift packages from the rear to the compartments that could take more load....ie. 10 kg to the nose and 60 to wings which brings it back inside the envelope. I might be overthinking this one.

Refer to ECHO loading system RPL-PPL-CPL Workbook. Page 16 to 19.
An Echo aircraft has a basic empty weight and moment of 1963 kg and 490.75 index units respectively. It is loaded as follows:
Row 1 ...................... pilot and one passenger [77 kg each]
Row 2 ...................... two passengers [77 kg each]
Row 3 ...................... two passengers [77 kg each]
Nose compartment ........... nine 5 kg packets
Wing compartments .......... four 10 kg packets
Rear compartment ........... eight 10 kg packets

The minimum number of packets that must be removed from the aeroplane, to ensure that the centre of gravity remains within limits at all stages of the flight is

Paul, just a quick thought that maybe the packages are different sizes and physically will not fit in the nose or wing compartments. Always follow the examiners direction. Removing weight from the rear compartment has the greatest impact on moving the C of G forward.

Cheers W

Some comments if I may ...

[color=blue](a) . Q40. When fuel is burnt from auxiliaries i understand that it stays within the envelope. I did another practice exam and got it wrong with this answer…they did mention 2360kg in the question which Bob covers in the text. If that question pops up in the exam what would you suggest the answer is if they don’t mention weight ?[/color]

Careful. There is no reason why the fuel burn will keep you in or out of any particular area of the envelope. Problem belong pilot to keep under control. The OEM is not going to go out of its way to make things needlessly difficult but there is an expectation that pilots have a basic level of weight control competence and a healthy fear of death if they get things excessively wrong.

[color=blue](b) Q40 - As the aux fuel is used, the C of G moves forward. The forward limit moves forward at a faster rate as the weight changes.[/color] [color=red]This is a design feature to ensure that the aircraft stays in balance as fuel is burnt[/color].[color=blue] At a weight of 2360kg, the forward limit of C of G stops moving and it is doubtful that there would be any fuel remaining in the Aux tanks.[/color][/color]

I suggest not the case. The usual problem relates to the relationship of forward CG and stall speed. Certification stall speeds feed back into things like takeoff and landing speeds. As these speeds go up, so does the takeoff and landing distances. The OEM wants to flog aircraft to the marketplace. They are not going to put up with needlessly high stall speeds. Usually, there is not much in the way of a load control penalty if we lose that upper forward bit of the envelope. Generally, for lighties, you will find that the forward sloping CG part of the envelope just happens to have some relationship to a fairly constant sort of stall speed variation ie the OEM gets a commercial benefit without causing any major upset to the customer.

[color=blue](c) Most questions state load not to be changed etc..[/color]

The question should state what the questioner intends. For CASA exams, keep in mind that a lot of questions are marked electronically. It makes things a lot harder for coding if the computer has to look at a heap of permutations and combinations. Far easier for the examiner just to limit things a bit.

Thanks John...I do prefer to understand rather than learn questions so appreciate your reply and commentary.

Cheers,

Paul