Bob Tait Aviation Theory Forum - Recent Topics

ppl performance

Ravi — Sun, 13 Sep 2026 12:40:03 +0000

Respected all, now onto CPL performance. On page 114 of the e text I used the wheel to determine the head wind and tail wind to establish ground speed . The parameters FPT 040M forecast is 120deg 20 kts @ 10 E variation so 110 Deg Magnetic. I used the wheel which gave me the head wind of 7 Knots going out to give me a GS of 173 - that I got but then turned the wheel to 220 for the reciprocal and got a tail wind of the same value. Therefore how is the tail wind 185 and not 187?

Please can you assist

Forward limit

JBULL — Sun, 23 Aug 2026 03:00:30 +0000

G'day everyone,

I have a question regarding the FWD limit.

I understand that when you need to add or subtract weight and the aircraft is forward of the forward CG limit, you can use the chart to plot the current CG and then add the weight and moment to determine where it intersects the FWD limit.

However, I find this method can be difficult to get an accurate answer because it depends on how precisely you can plot and read the graph.

Is there a way to mathematically double-check the result, rather than relying solely on the graph? Or is the graph generally intended to provide a rough answer and get you close enough to the correct value?

Thanks in advance for any help.

Fuel calculations. PNR Fixed reserve / Holding

Patrik — Wed, 29 Jul 2026 23:55:49 +0000

Hi everyone :) I am little confused about how to calculate the Final reserve fuel. When I use bob Tait exams, we use cruise fuel flow but other exams the use the holding fuel flow. What is it? Holding fuel flow or Cruise fuel flow?

Online Learning

andylittle — Mon, 27 Jul 2026 04:07:46 +0000

Hi all, are the online learning textbooks automatically updated with each new errata issued?

Thanks, Andrew

Recency requirements - question 45 from PART 7 the general questions

Pontius — Fri, 24 Jul 2026 23:25:48 +0000

The answer guide gives choice c/ for the conditions in the question. Why is the answer not a/. The question does not imply that a circling approach would be needed hence the requirement stipulated in answer c/ is redundant?

Thanks for any advice.

LSALT calculation when No IAP - IREX online practice exam 3. Q . 24..

Nick Smit — Sat, 18 Jul 2026 15:25:38 +0000

IREX question — could someone please clarify?

Hi all, could someone please have a look at this question and explain why 2100 ft is considered the correct answer?

According to the AIP, my understanding is that the required altitude should be:

Grid LSALT + 500 ft = 1900 + 500 = 2400 ft (or 2600 ft depending on the chart/grid value used)

So I was expecting the answer to be closer to 2550/2600 ft, not 2100 ft.

Question:

You depart Caiguna (S32.16.8 E125.28.7) for Forrest (S30.51.3 E128.06) in VH-OZY. Your intention is still to return to Caiguna should an engine fail in IMC after departure. You plan to track to Forrest via W486.

To allow you to depart under these circumstances, there must be no more than four eighths cloud below an altitude of:

a) 2800 ft
b) 2100 ft (marked correct — can someone explain why?)
c) 2550 ft
d) 1813 ft

My understanding is that for an engine failure in IMC after departure, the return route clearance should consider LSALT + 500 ft, so I’m unsure where the 2100 ft comes from.

Would appreciate any explanation or AIP reference.

TIA

Untitled.jpg

ICAO CPL + IR (Argentina) to CASA conversion - study resources & advice

LucasEsposito21 — Fri, 10 Jul 2026 21:07:15 +0000

Hi everyone,

I hold a CPL and Instrument Rating issued in Argentina under ICAO standards, and I'm starting the process of converting to an Australian CASA licence. As I understand it, this means CHUF + COSA for the CPL, plus a flight test, and possibly something separate for the IR (still confirming with CASA exactly what applies to the instrument rating conversion).

A few questions for anyone who has been through this:

1. Where did you study for COSA specifically? I understand it draws from CPL Air Law, Meteorology and Navigation rather than being a single clean subject - did you use a single book/course or combine a few?
2. Any tips on the CAR/CAO/CASR extracts or permitted materials that made the biggest difference for you?
3. If there's anyone from Argentina or elsewhere in South America who has done this conversion, I'd love to hear about your experience - particularly around the language side of studying Australian law/documents as a non-native English speaker, and how you handled the instrument rating side of the conversion.

Any advice, resources, or war stories are very welcome. Thanks in advance!

adding weight vs shifting weight

Jess — Mon, 06 Jul 2026 04:49:09 +0000

Hello. I have been doing various practice exams about the place and have come across what may just be an inconsistency but may be something I am missing. Some questions want me to move weight before I add ballast, some questions do not, unless the question specifically says one way or the other, what does CASA expect? For example, what is the minimum amount of fuel required in the main tanks as ballast in an ECHO loaded as follows: 1970kg and 475.66 index units, row 1 154kg, row 2 154kg, row 3 160kg and rear compartment 5 x 30kg packages with 5 kg sandbags available?

If I move one package from the rear to the front and then add three sand bags I get well inside the rear limit, but if I don't move the package from the rear I do need ballast fuel even with 40kg of sandbags in the nose locker. I had not seen the shift-before-you-add method until recently, is this the new thing?

Revision Test 8. Question 41. Page 89. Personality types. (P, G etc)

lusty-urban-entomb@ — Sat, 13 Jun 2026 11:27:31 +0000

Hi all.

Just thought I'd introduce myself first. My first question here probably the start of many. Studying for CPL-H. Only sat CHUF and failed at 63%. Seeking a little human help if anyone could be so kind. I will help if I can. Seen some great explanations so far.

Why is an instructor who allows a deviation from approach, person directed but not goal directed (P+G-)

Could anyone explain this any better than the explanation on page 79?

Many thanks

Evan

about to do Human Factors

Ravi — Sun, 24 May 2026 14:58:36 +0000

Greetings all

Just wanted to know about the Human Factors exam preparation. Im planning on sitting in a few months.

I have the Bob Tait Text but

1 Is there any other material that is required, like the material from CASA on Human Factors

2. There were apparently questions asked about flight duties and hours, which are ATPL subjects, where do I get this information from?

Kind regards

Ravi