Howdy,
I've been working through the performance book, sitting the exam next week.
On page 102 you're asking for minimum fuel calculations. As per the new CAAP - variable fuel is trip fuel only (it does not include alternate). I take this to mean that we multiply our trip fuel by 1.1 (10% variable) then add the Alternate. Is my interpretation incorrect or has this just been overlooked? It changes some answers by several gallons. CASA have you manually type in many answers now and they won't tell us the tolerances, if we don't get these calculations correct I think it'll be the difference between pass/failing those questions.
Also, you have updated answers to include the new CAAP (question 9/10 on page 98) but it still states 45 mins Fixed reserve when it should be 30 mins 🙂
Cheers!
G'day Kaos
[strike]Your interpretation is incorrect, flight fuel = (departure to destination and on to the alternate) x 1.1 + holding + taxi*
*(depending on the question).[/strike]
EDIT: Flight fuel is no longer used it is now trip fuel and the variable reserve only applies to trip fuel as such the calculation is now
[Trip fuel] x 1.1 + Alternate fuel + Holding Fuel + Taxi fuel (depending on the question)
Page 98 question 10 you are correct it should be 30 minutes as it's a private flight
I'll change the question to reflect that
Cheers
Cheers for the quick response. Also while I remember, the link in the new performance e-text is for the old CAAP not 234 (2)
In the definitions of the new CAAP (copied below) it gives the definition for Trip Fuel (not Flight fuel anymore) and Variable. The note at the bottom of Variable states it does not apply to alternate fuel?
The amount of fuel required to enable the aircraft to fly until landing at the destination aerodrome, taking into account the operating conditions in paragraph 3.3. This includes (as applicable):
a. fuel for take-off and climb from departure aerodrome elevation to initial cruising level/altitude, taking into account the expected departure routing, and
b. fuel for cruise from top of climb to top of descent, including any step climb/descent, and
c. fuel from top of descent to the point where the approach is initiated,taking into account the expected arrival procedure, and
d. fuel for conducting an approach and landing at the destination aerodrome.
Variable fuel reserve The amount of fuel required to compensate for unforeseen factors. It shall be the highest of the percentage of the planned trip fuel specified in column 4 of Table 1 for the applicable category and class of aircraft or, in the event of inflight re-planning, the percentage specified in column 4 of Table 1 for the trip fuel from the point of in-flight re-planning, or the fuel required to fly for 5 minutes at holding speed at 1,500 ft above the destination aerodrome elevation in ISA conditions (as applicable).
Note: Variable fuel reserve does not apply to alternate fuel.
If you look at the sample fuel calc annexes, they work out variable fuel reserve based on trip fuel not trip + alternate.
G'day Kaos
You have a point there we didn't catch that change in the CAAP we have emailed CASA and will report back with our findings.
I guess you don't ever have unforeseen headwinds when going to an alternate anymore CASA must have done a deal with God.
Cheers
Hahah feel sorry for you and the team Stuart! You've probably already changed most of the textbook and online course and exam questions have you?
Never ends Lucas 🙂
:laugh: :laugh: :laugh:
Thank you! Thought I was going crazy for a second there!! Appreciate the follow up 🙂
Always fun learning about the 'interesting' choices CASA makes for us 😛
The CAAP workbook is clear, Alternate is not included in variable calculation. However, the CPL Performance Supplement states company policy requires it to include Alternate in 10% variable calculation (asterisk comment under Fuel Policy). In exam do we follow CAAP or company policy?
I see your point I'll amend that to reflect the changes it was missed when we did the update
[color=blue][i][b]Alternate is not included in variable calculation. However, the CPL Performance Supplement states company policy requires it to include Alternate in 10% variable calculation (asterisk comment under Fuel Policy). In exam do we follow CAAP or company policy?[/b][/i][/color]
Some thoughts to ponder -
(a) the rules are the MINIMUM standard ie you go below the rule requirement at your peril unless in emergency situations where the commander exercises command prerogative. Keep in mind that the CAAPs, while generally useful guidance, don't carry the weight of the Act or Regulations. The pilot in command is always required and expected to think about what he/she is proposing to do or is doing. YOU can find yourself in court, very much up a creek without a paddle, if you get things wrong.
(b) company requirements (ie in the Operations Manual or similar CASA-approved/accepted documents) will be equal to or conservative in respect of, the minimum rule requirements. You follow the SOPs as published for your minimum standard of operation in routine circumstances. If you detect a non-conservative error in the SOPs, you then draw that to the attention of the operator's management folk
(c) leaving alternate fuel out of the VR calculations is fine and, in general, will be covered by various items of margin fuel in the event that the alternate is availed. Also, destination VR often is not used entirely. However, he/she who just blindly omits VR for the alternate without due consideration of what he/she is going to do and where he/she is going to find the alternate VR in the event that the alternate is to be availed ... is just not thinking up to the required command standard. If, on today's story, you need a bit more fuel to give you an out in the case of diversion .. you carry the bit of extra fuel. Otherwise, you run the very real risk of finding yourself out on a limb at the destination when you can't get in due wx or, perhaps, a disabled aircraft on the intersection ?
(d) A point in question - a very short trip to the destination and a long trip to the diversion alternate with no required holding. Do you just carry destination VR and no margin fuel ? Could be a bit silly. In some operations, VR routinely is applied to the longer of destination and alternate fuel requirements. At all times, the aim is to leave yourself with an out .. suggest you have a read of this report
https://www.atsb.gov.au/media/5773678/ao-2009-072-reopened_final.pdf
Do you think that the commander on the day and the company operations support organisation supposedly backing him up did a good job ? If you do, think again about whether you should be commanding an aircraft ...
Keep very clearly in mind .. when push comes to shove and it all goes horribly wrong, the commander is there, all by himself/herself, out on a limb with guns pointing from every direction !
Engineering specialist in aircraft performance and weight control.
That's another one we missed when we updated. Fixed now - thanks for your feed-back. Much appreciated..
Follow on to this. The CPL Performance Supplement (which is part of the book) mentions Company Policy requiring an Alternate is part of Trip Fuel.
However when I download the supplement which is handed out in the exam itself ( https://www.casa.gov.au/sites/default/files/rpl-ppl-cpl-aeroplane-workbook.pdf) it appears that no additional guidance is given regarding Company Policy other than to adhere to the CAAP (i.e. an Alternate is NOT part of Trip Fuel).
That is correct and our supplement has been amended to reflect that. The fuel policy is simply to adhere to the CAAP.
