Bob I have a question for you, something I have not come across yet in your book while using hard and fuel ballast's to find the minimum fuel ballast required.
If no passenger is on the second seat in row one, we could not only fill the forward compartment, but add a further 77Kg onto the seat right? Providing ZFW permits
And if the seat was to be removed we could add an additional 5Kg, which is what the seat weigh's anyway.

Likewise if we were given a number of passenger's, but they were all lighter than 77Kg, we could place them in row 2 and add 77Kg of ballast in row one.

Ofcourse if this may be 70 or 75 if set weight sand bags were used.

Thanks in advance

You are absolutely correct. There is no reason why you could not add ballast to an empty row one seat, however you would have to watch out for zero fuel weight. The examiner often gives you a load will bring you to the ZFW limit after you add hard ballast to the nose. If that was the case, you could not add anything to row one even if it was empty.

Your idea of swapping a lighter passenger for a heavy one in row one would also work. I doubt if that scenario would apply in an exam question though.

Bob

Thanks Bob, most useful as always

Bob,

I'm unclear of the definition of "Operating Weight" I you are told the operating weight and also told the seats have been removed does the operating weight already take account of the removal of the seats or are they a deduction to be made in the calcs??

Thanks,
Jeff

Hi Jeff,

The operating weight is essentially the weight of the aircraft without useable fuel and payload. If they give you an "operating weight" and state the seats have been removed then you would assume the weight of the seats has already been taken out.

Cheers,

Rich

I found when sitting the exam they make it reasonably clear whether they want you to subrtact the seats or whether it has already been done. I only had one question where I had to remove the seats, and that was the typical question where you're given a weight and moment index, and then asked to remove the seats and come up with the new moment, COG etc.
My advice is if you have a question which involves removed seats, read it carefully, if you are still unclear whether they have taken the moment and weight away, then just assume they have, as all weights and moments I had were true operating weights and all those calculations had been done for me.

My last CPL exam and the only one I was truely dredding, and walked out very proud with 100%

A big thanks to Bob Tait and the others who gave advice here. PPL flight test in a couple of weeks then the Irex study begins, joy.

There is at least one question like this in the CASA database - I got it yesterday. The ZFW was well and truly under the limit (~2400kg with payload).

I chose to add 75kg worth of hard metal bars to the row 1 seat after filling the nose prior to calculating the minimum fuel ballast and I got the question wrong, so I would suggest that you do not add hard ballast to the row 1 seat in CASA exams.

Just to complicate things further, the question also provided basic empty weight and moment, then when listing the payload in row 3 of 160kg of cargo added that the seats in this row had been removed - no indication that the basic empty weight/moment reflected this so I subtracted 10kg from row 3 for the seats as well. This has a surprisingly large effect on the outcome of the answer too for such a small weight.

Hi Ray,

We've been having this discussion over at the CPL-Perf course forum and if they give you a BEW and MI and tell you the seats have been removed you will normally assume the values are for the aircraft with the seats out.

Cheers,

Rich

P.S. by the way, thanks for some great answers on the forums here. Your help is undoubtedly much appreciated by your fellow students. Well done!

In all the questions I encountered where seats were removed, they gave the BEW details with seats removed, and clearly stated this; and where they were removed, they were removed because other equipment had taken their places, therefore I did not have to decide whether or not to add ballasts in change of the seats, as the stations were full. Maybe I just got lucky, but this is something I was stressing about a little before the exam, in fact this was the only exam I really stressed over, yet achieved 100%
My advise to others would be to study the Bob Tait book through and through, then sit the exam with confidence, I think the more you worry about these little perdantics the more uneasy you enter the exam room. Go in feeling confident, and even if you do get thrown one or two trick questions, you will still pass with ease. I think dealing with numbers is more straight forward in CASA exams than dealing with words and structured sentences, such as the AGK exam!

100% in Performance? Wow, outstanding effort mate, well done! It is obvious you have nailed this subject well and truly. Thanks for the exam feedback too. It will be a comfort to others facing the CFPA exam.

Cheers,

Rich