I am planning on sitting the performance exam. 

Good man, that man.  You'll find performance relatively straightforward in that, providing you know your stuff, the questions fall out in a pretty straightforward manner.

As CASA doesn't release the exam questions, it is a tad difficult for us to nail down exactly what is in the questions, save what we might deduce and infer from student post-exam comments.

Are the questions in the bob tait book similar to the exam

General comment feedback suggests that Bob's material is pretty relevant to what you might expect to see in the exam.

The supplement that is in Casa is that the same as the supplement from the Bob Tait

Suggest you download the CASA exam booklet from the CASA website to make sure you see the words as they are written.   Having said that, I recall that Bob included some planning data which is additional to the CASA booklet.   As there are various editions of the booklet, make sure you have the version which includes the red text "FOR EXAMS FROM 2 DECEMBER 2021 ONWARDS".

I understand there are 2 part and 4 part questions

Not sure that I understand just where you are going here, so I must leave any comments to others

Some questions take some time even to read, are the questions similarly verbose

The exams have been noted in respect of a touch of verbosity.

The formulae re the weight to shift etc are they to be learnt off by heart?

Most students, regrettably, tend to a philosophy which emphasises just getting the pass and less of the learning about the subject material.  For these folks, learning a formula takes a lot of pressure off them.   For the weight shift problem, in particular, the formula is not necessary as it just echoes a simple moment balance.   You can get to the answer, quite easily, by setting a datum at the desired cg, running a moment calculation and setting the total moment to zero.  Such is what we mean by the term cg.

What percentage are ECHO questions.

As the other aircraft have been examined at RPL/PPL level, it is reasonable to expect the majority of questions to focus on the Echo.

Do you have to use TAS or ETAS in the answer

ETAS is a bit of a bugbear for me.  This (very sensible and appropriate) term was coined by EBJ, or one of his cohorts, almost immediately after he assumed control of the patent from Lahr/United Airlines in the mid 50s.   

ETAS is just the value of TAS resolved along the track vector in the solution of the wind triangle.  For those interested, ETAS=TAS x cos(drift) - no more, no less. 

Presuming that we are considering the use of either the Dalton (E-6B and E6B/E6-B clones) or the Jeppesen (CR or clones), ETAS has nothing to do with the Dalton solution (ie forget it) but is always required for the CR solution.   Please brain dump the 10 degrees drift nonsense idea in the CR description of ETAS - it was introduced by Jeppesen for in-flight considerations but introduces an error into the calculation which is counterproductive for the CASA exams - just figure ETAS every time for every question using the CR (regardless of drift) and you won't go far wrong.  Further, the approximation is totally unnecessary as the ETAS calculation takes about 1-2 seconds at most.

So, getting back to your question.  If you are using the Dalton, forget ETAS - not relevant at all.   If you are using the CR, always use ETAS as it is an integral part of the solution.  One caveat: if the question is looking at wind components along track and doesn't have enough information to figure the numbers in the usual flight planning manner, you really need to use ETAS, rather than TAS, to relate the numbers.   If you are using a Dalton, while the device doesn't need, or use, ETAS, you can figure the ETAS value, quite easily, by using a Douglas protractor to drop a perpendicular from the end of the TAS/HDG vector to the track vector - ETAS is the length of the resulting part-TR/GS vector.

Were there many questions that required the runway distance supplement in the ERSA

Expect some.  If you are having difficulties with the ERSA, please post some questions and we can sort any problems out without any difficulty.

What is the best flight computer to use, the circular or the slide ruler one?

Presuming we are talking Dalton or CR, which are the two main computers in the marketplace, it doesn't matter in the slightest.   You'll get the same answers, providing you run the devices in the correct manner.  Most of the Daltons don't include any compressible flow correction (the ASI is calibrated for incompressible flow due to historical considerations and it overreads at higher Mach numbers) so, with the basic computer, you need to apply either a CAS to EAS or F-factor correction to get the correct TAS.  Most people tend to go with the line of least resistance for the ATPL exams and use the CR (which applies the correct compressible flow equations) but, for PPL/CPL, either flip a coin or choose the one you prefer against any criterion.  Each is easy to use, once you have been shown how it really works - generally, the accompanying user manuals are pretty average.  One point to note - the CR gives you two ways to figure TAS.  The traditional way is the same as on the Dalton and needs the compressible flow corrections to get the correct TAS answer.  This uses the cutouts labelled something like "True Airspeed Calculation" which sets up (on the outer C/D log scale against 10) the value of 1/√σ used in calculating TAS from CAS/EAS depending on Mach number.  If you use the Huber Supersonic TAS computer, which is overlaid on the calculator side of the CR, it incorporates the compressible flow equations and you don't need to apply a compressible flow correction.

We'll see you giving medicine away and becoming an airline pilot, yet, good sir.

@john-heddles Amazing advice as always. The only way Im going to afford flying is through medicine so much as Id like to, Im going to have to stick with it.. but also I still enjoy it. Perhaps I want to enjoy both. I appreciate your sentiments on understanding and that I believe is key to everything so yes do try to do this. Im also trying to see if the ETP and PNR have similarity to the crossed ladder theorm. A topic for another day !

Many many thanks once again.

Human factors I passed with significant ease. No KDR except in the TEM but then that is not from lack of understanding I feel but considerable confusion over nomenclature and I think Ill have to write have to write a discertation on this as I think some of the wording in TEM is in itself a potential cause of threat and error! but that is with my professor of surgery hat on!

Kind regards 

Ravi 

I'm also trying to see if the ETP and PNR have similarity to the crossed ladder theorem 

The off-track ETP/PNR calculations have a passing similarity, much to the chagrin of ATPL students.

Human factors I passed with significant ease

I would have been absolutely surprised had that not been the case.

considerable confusion over nomenclature

I suggest that you have many hundreds of CPL/ATPL students who would enthusiastically echo your observation.

@john-heddles 

Thank you I have seen in the Bob Tait exam book on using the 2 difference computers re the derivation of the ground speed and therefore with the Dalton,  you dont need to use the ETAS and then with the CR you have ETAS easily able to be calculated using the drift correction factor. You did outline a method of ETSA...

If you are using a Dalton, while the device doesn't need, or use, ETAS, you can figure the ETAS value, quite easily, by using a Douglas protractor to drop a perpendicular from the end of the TAS/HDG vector to the track vector - ETAS is the length of the resulting part-TR/GS vector.

However suppose CASA asks you to calculate ETAS and you only have a DALTON, can you please share a picture on how you calculate this please

or 

Am I barking up the wrong tree and CASA doesnt as questions to calculate ETAS?

Kind regards

Ravi

with the Dalton you don't need to use the ETAS and then with the CR you have ETAS easily able to be calculated 

With the Dalton, it's not just a case of not needing to use ETAS - you cannot use ETAS as there is nowhere to use it in the graphical solution of the full triangle - it has absolutely naught to do with the Dalton solution, it is only pertinent to the CR solution where the vector items are resolved along the track vector and ETAS needs ALWAYS to be calculated if you want the correct answer.

suppose CASA asks you to calculate ETAS and you only have a Dalton or am I barking up the wrong tree and CASA doesn't ask questions to calculate ETAS?

Absolutely the latter.   It is child's play to figure ETAS on the Dalton - see below.  However, were CASA to ask exam candidates to work out a value for ETAS, Gavin would have a riot on his hands - the folks who use a Dalton would have no idea what the question was on about .. ETAS ? what on earth is that ?   

I'll knock up some graphics to show how ETAS relates to the CR solution, and how to find ETAS on the Dalton, in the next few days.  It's dead simple, once you see how it works.

Organisations which insist on students using the CR will include exercises in calculating ETAS to reinforce the technique but one needs to keep in mind that figuring ETAS on the CR is a trivial calculation taking around a second to accomplish.   But it is certainly of no concern when it comes to specific CASA exam questions.

I guess a lot of students have been seduced into using the CR, largely due to Jepp's aggressive marketing in the early days (50s through 70s) -  shades of Microsoft ?   That's fine, but it really doesn't matter at all which one you use, especially for PPL/CPL.   The only significant differences are

(a) the CR is smaller and fits in one's shirt pocket, while the Dalton lives in the navbag, and

(b) the CR incorporates Huber's computer for higher Mach number TAS calculations - which uses the compressible flow equations - and avoids the need for the corrections which are required on most of the Daltons.