Bob Tait Aviation Theory Forum - Recent Topics

TAF3 query

Ravi — Sun, 10 May 2026 00:21:30 +0000

Supposing you have a TAF3, arriving in Sydney. The TAF3 is from 220730Z and the conditions are fine to land ( no alt or holding required )

Then FM220900 the conditions change to 26006KT 9999 thunderstorms FEW015 BKN018CB

Your ETA is 0850Z

The question asked how much holding/alternate requirements are needed if the following is forecast at Sydney.

My thoughts that as long as you arrive before the FM, then no alternate or holding is required? Is this correct?

Assuming that if you were to land at 0900, then the conditions require that an alternate is required is that correct?

I understand that in the first 3 hours of TAF3, the time buffers do not apply, but will apply 30 minutes before and after if it is after the first 3 hours

I also understand, that in a TAF3, from ENR1.1 10.7.2.9 that only any reduction in visibility or if there was a PROB30 or PROB40 for TS or associated severe turbulence, then you can ignore this? But if there were other deteriorations ie. if the CLOUD was > SCT below 1500 at ETA, or if the wind was > aircraft could handle? or if there was a definate TS at arrival, then holding fuel would be required? Is this correct?

Is there any reason why CASA has included only 2 parameters to ignore and not the others

Kind regards

Ravi

Some posts are unavailable

Ravi — Sat, 09 May 2026 06:13:02 +0000

There are some posts that come up as 404 and I think they re related to exams

I am about to sit the CPL Met and wanted some generic guidance. Can someone assist.

Id like to know without specifics what types of questions?

The Sydney WAC and PCA are required material but were they of use

How close are the Bob Tait practice tests similiar to the real?

Ive also read the BOM aviation knowledge center and wondered how close or accurate that is?

Any guidance will help

Kind regards

Ravi

CASA EXAM Change to exam permitted materials

Bob Taits admin — Thu, 07 May 2026 01:23:37 +0000

Student Notice – CASA Plain English Guides

CASA has announced that the Plain English Guides may now be used in examinations where the corresponding current legislation is listed as permitted material.

For example, if an exam permits access to Part 61, then the Part 61 Plain English Guide may also be taken into that exam. The same principle applies to other Plain English Guides where the relevant legislation is permitted.

Students must remember that the current legislation remains the primary and correct source. The Plain English Guide is only a supporting document. If there is any difference between the legislation and the guide, the legislation overrides the guide.

At this stage, CASA has not produced Plain English Guides for Part 121 or Part 135. Therefore, there are currently no Plain English Guides available for those Parts.

Please make sure your exam materials are current, permitted for the exam you are sitting, and used correctly.

PNR - Contingency Fuel

expat87 — Mon, 27 Apr 2026 02:49:32 +0000

When calculating a PNR for a Part 135 flight with a 10% contingency requirement, I would like to confirm the correct interpretation of safe endurance.

My understanding is that the trip fuel for the original A to B sector is not used in the PNR calculation, because once the PNR is being determined the relevant flight becomes:
Departure -> PNR -> Departure

Therefore the safe endurance should be:

PNR trip fuel = (Fuel at take-off − final reserve fuel − holding fuel) ÷ 1.1
with the PNR trip fuel then converted to time at the applicable cruise fuel flow.

The reason I am asking is that the original A to B flight may contain margin fuel, and I want to confirm that the 10% contingency is applied only to the fuel required for the PNR return calculation, rather than being based on the originally planned A to B trip fuel to destination.

Can someone confirm whether this is the correct interpretation?

CPL CNAV exam apparent GPWT/GAF questions

James_Fatchen — Mon, 27 Apr 2026 00:49:12 +0000

Hi all,

according to my practise exam provider there is a possibility of GAF and GPWT questions in the CNAV exam! However there is nothing I can see in Bobs CNAV book that references GAF/GPWT, is this something I need to consider before sitting the exam?

thank you

POWER OUTAGE.

Bob Taits admin — Wed, 22 Apr 2026 07:29:54 +0000

Apologies, our servers were unavailable for most of 22 April after the Council shut down power to the airport. We experienced some difficulty restoring the server systems once power was returned. Services should now be back online and operating normally.

RPL-N exam study

Justin — Wed, 08 Apr 2026 11:11:50 +0000

Hi guys,

I’m studying for my RPL-N exam. To make the most efficient use of my time, is there a recommendation of what chapters to study from volume 1 and 2 please?

Cheers!

happy easter - studying hard

Melanie — Sat, 04 Apr 2026 03:31:27 +0000

Hi there, just introducing myself. on my last CPL subject - Performance. I have been working through, self studying for about 20 months now from PPL, through IREX into CPL. bob tait has been brillant.

The books are very thoughtful and from a giant math avoidance person I can follow it thorough and make passes.

CPL Performance Figuring out how the online course fits with the book

Melanie — Sat, 04 Apr 2026 03:27:27 +0000

I am working my way through the book and doing the online course at the same time. I can't figure out how the course fits with the book.

So far I have watched videos 1-6 carefully. then looked through 7-12 to see how it fits, but cannot make them work against the book.

Video 1 - Pages 1-5

Video 2 - Pages 6-14??

video 3 - Pages 16 - 19??

Video 4 - Pages 22 - 65?

Video 5 - pages 67 - 109 - but there does not seem to be any video on climb gradient, GS and time interval,

Video 6 - pages 137 -?

Video 7 - jumps back to page 110 - 119??

Video 8 - pages 120 - 136??

Video 9 - pages 139 - 150?? - this video just starts in the middle of a sentence

Video 10 - pages 151 - ?

Videos 11 and 12, I can't figure out how they fit in.

the problem is, after video 4 it appears to be chaotic for videos 5-12.

Can someone help me out with the structure please.

IREX Questions

Christopher — Thu, 02 Apr 2026 13:09:09 +0000

Hi everyone,

I have a few questions and I have the exam soon.

If you only have 1 VHF + 1 HF Com and you need an alternate, and that alternate has PAL, do you need to carry 30 minutes holding fuel if flying by day AND/OR night or do you only need the holding fuel if you're flying at night? AIP ENR 1.1 10.7.4.4 doesn't really specify at what time of day you need it.

Will I have to calculate BOD for a certain destination aerodrome in the exam if I need to calculate holding fuel for BOD + 10 mins or will the BOD be given in the question?

The textbook says that you can use Grid LSALT in the calculation of alternate minima and takeoff minima for aerodromes withn no published IAP, however, the regs for visual approach requirements talk specifically about LSALT/MSA for "the last route segment". I looked up the specific definition of a route segment in the ERC low user guide and it says that a route segment has a defined LSALT, track, and distance etc. Doesn't that technically mean you can't use Grid LSALT because it's not a "route segment" LSALT?

Also, I was doing a practice exam and got this question:

You are approaching Townsville at 0312Z. You wish to obtain the latest meteorological reports for your arrival.

The time and frequency on which the next VOLMET for Townsville will be available are -

Select one:

0330 on HF

0400 on HF

the current time on VHF

0330 on VHF

I selected current time on VHF because I thought you could use the Bellenden Kerr VOLMET (119.75Mhz) or the Mt Blackwood VOLMET (119.85Mhz) but the correct answer was 0330 on HF. Is it based on the fact that you need to be on continuous listening watch on at least 1 VHF frequency and that's why you select the HF VOLMET? I'm a bit confused here as well.

Thank you