CARS oxygen requirements

[Stunty]

I'm self studying for my CPL and am finding the section in the AIM/CARS on Oxygen requirements very confusing and poorly written.

Firstly, a question from the 2004 Culhane exam book is throwing me. You are on an unpressurized commercial acft having 7 pax and 2 crew to be operated at 12,000 for 45 minutes. The flight crew require how minutes of oxygen supply, The pax require how many masks, and the pax require how many minutes of oxygen?

Well I figure looking at the table the crew need 30 minutes total (15 each), the pax need one mask, and the pax need 15 minutes Oxy total, based on the fact that under 13,000 10% pax need masks, and everyone has to suck oxy for the period in excess of 30 minutes. Apparently the answer is 1 hour for the crew, 1 mask for the pax and pax need oxy for entire period above 10k?

Now onto the pressurized aircraft table. My biggest issue is the first part of the table states all crew and 10% pax require oxy for the entire period above 13k. Next part says all pax need oxy for the entire period above 13k Which is it - 10% or all pax.

Ideas?
Thanks

[CD]

I'm self studying for my CPL and am finding the section in the AIM/CARS on Oxygen requirements very confusing and poorly written.
...
Ideas?
You are correct. The charts in 605.31 were intended to clarify and simplify the requirements from the ANO/Air Reg days. Unfortunately, that didn't happen... :ugh:

Proposed changes have been accepted through the CARAC process (http://www.tc.gc.ca/civilaviation/regserv/Affairs/carac/menu.htm) that once again, are intended to fix the problems. You can review the history of the problems associated with the oxygen requirements as well as the proposed changes at these two links:

NPA 2003-020 - Supplemental Oxygen Requirements For Unpressurized Aircraft (new 605.31) (http://www.tc.gc.ca/civilaviation/RegServ/Affairs/carac/NPAs/CASO/Archives/feb03/2003020.htm)
NPA 2003-021 - Supplemental Oxygen Requirements for Pressurized Aircraft (new 605.32) (http://www.tc.gc.ca/civilaviation/RegServ/Affairs/carac/NPAs/CASO/Archives/feb03/2003021.htm)

However, they still have to go through a legal review so who knows what the final version will actually look like...:hmm:

While this information is not likely going to help you now, at least there is some hope that the current problems will be fixed (and not just replaced with more :} ). To check the status of these or any other regulatory change, you can use this website:

CARAC: Notice of Proposed Amendments (NPAs) System (http://www.tc.gc.ca/aviation/applications/npa/)

[Stunty]

Oh good. So im not completely stupid then. Thanks for the NPA info.

Agreed the pressurized table is a dogs breakfast.

However, the unpressurized table is fairly straight foward - any ideas why I am getting this question wrong? Is the answer in the book wrong? In the table the reference about crew needing a minimum of 1 hour on transport ops only applies to flight above 13k. So to me it still looks like the answers are 30 minutes, 1 mask, 15 minutes.

Thanks
stunty.