View Full Version : Another IREX Question
6th Aug 2012, 09:11
This one relates to take off minima from the Bob Tait Book (CIR Revision Questions, Set 2, Question 9:
"You are on the ground in Brisbane in a category B twin. The aircraft is equiped with 2 VHF NAV with glide slope, 2 ADF's on one SACA approved GPS, but the DME is unservicable. You do not have a flight director or coupled autopilot. No PEC is available for your aircraft. Conditions favour RWY 19. Your aircraft has no pressure error correction data. If your intention is to return in the event of an engine failure in IMC after take-off, the minimum ceiling and visibility required for take off is;
As i read it, the take-off minima for this particular aircraft is 300' and 2000M (no mention of number of pilots, jet etc. etc.).
The answer in the book is based around the RWY 19 ILS Z minima, adding 50' for no PEC (book says 257', but it's 259 on current plate) and 1.2km vis due no FD or AP. I understand how this would be the answer if it was more restrictive than 300' and 2000m, but it is not.
Why is 300' and 2000m not the answer, since this is the more restrictive limit?
6th Aug 2012, 10:54
You will find the answer for that in ENR 1.5 para 4.4.4a. If a return to land at the departure aerodrome will be necessary in the event of an engine after take off - the meteorological conditions must be at above instrument approach and landing minima for the aerodrome.
If the chart says 257' and 1.2kms vis, then thats your new take-off minima.
Hope this helps.
6th Aug 2012, 14:29
Sorry, Forgot to fully answer your question.
Why is 300' and 2000m not the answer, since this is the more restrictive limit?
In this instance, the question uses and aerodrome with an approach that has a lower cloud and vis minima. Other aerodromes will have higher take off minima because of the approach if you will be returning due engine failure.
The exam doesn't take into account what you think would be more restrictive or what you think the safer option will be.
The question is testing your ability to interupt the AIP and, after exploring all the options, apply the most correct answer.
7th Aug 2012, 03:59
That's not right.
The minima for take-off is 300' and 2000m. That is the minimum weather conditions the regulator has decided is necessary to safely take-off and cope with an engine failure. If you have things that make engine failures easier, such as two crew, auto-feather, turbo-jets etc then the take-off minima can be reduced. But if you don't have those things, the minimum is 300' and 2000m. What they are also saying is that if you intend to land back at your departure airfield in the case of some sort of failure then obviously you have to have weather conditions suitable for an approach, but if the minima for the approach are less than the standard take-off minima that doesn't magically make it easier to cope with an engine failure after take-off in a single pilot prop with no auto-feather.
To sum up, the take-off minima are the minimum weather conditions for take-off. The landing minima are the minimum weather conditions for landing. If you plan to take-off and land at the same aerodrome for whatever reason then the weather must be above both the take-off AND the landing minima.
7th Aug 2012, 04:43
Ask two lawyers and you will get two different answers.
But as far as I can interpret, the minima is 300'+2000m
Apparently you can't directly copy/paste text from AIP:rolleyes: but here is the key phrase.
4.4.4 It is a condition of the use of the minima in Section 4.4 (300'/2000m) by a multi-engine aeroplane that:
a. if a return to land at the departure aerodrome will be necessary in the event of an engine failure - the meteorological conditions must be at or above instrument approach and landing minima for the aerodrome or such as to allow a visual approach; and
All it states is that you may use the 300'/2000m minima only if the conditions are above the approach minima, it does not say that you may use a lower minima.
Also technically a return to land is necessary and the approach minima is something like 900'/4.5k it does not state that anywhere that you increase the take off minima to that level, it just means that you may only use the 300'/2000m minima if the conditions are above 900'/4.5k.
Gotta love oz air law.:E
Btw for that second point, in the IREX you don't get to argue your answer so you should put the higher landing minima in that case.
7th Aug 2012, 05:20
Couldn't agree more with you both, but that's NOT what is taught in many IREX courses (Bob Tait springs to mind), unless something's changed in the last few years.
I apply the same logic (flying piston types), if conditions are less than 300'/2000m, I won't depart, legal or not. I don't want to be tackling an EFATO in a piston twin in IMC at that level (or anywhere near it really).
It is (or was) taught in some IREX courses that if the ILS landing minima are less than the standard takeoff minima, you may use the ILS minima for takeoff. I seem to remember doing practice IREX exams where this gave a correct answer (I.e. using the ILS minima for takeoff).
7th Aug 2012, 09:00
Yikes. There are enough hurdles to stumble on without the text book giving you the wrong answer!!!
7th Aug 2012, 13:03
Throw the book away
Close your Eyes
Works for me !!:ok:
7th Aug 2012, 14:19
4.4 Take-off minima for other IFR aeroplanes
4.4.1 The take-off minima in Section 4.4 applies to an IFR aeroplane that is NOT a qualifying multi-engine aeroplane within the meaning of Section 4.3.
4.4.2 The take-off minima for the aeroplane are:
a. a ceiling of 300FT; and
b. visibility of 2,000M.
4.4.3 It is a condition of the use of the minima in Section 4.4 that the pilot in command of the aeroplane must ensure that:
a. terrain clearance is assured until reaching either en route LSALT or departure aerodrome MSA; and
b. if a return to the departure aerodrome is not possible, the aeroplane’s performance and fuel availability are each adequate to enable the aeroplane to proceed to a suitable aerodrome, having regard to terrain, obstacles and route distance limitations.
4.4.4 It is a condition of the use of the minima in Section 4.4 by a multi-engine aeroplane that:
a. if a return to land at the departure aerodrome will be necessary in the event of an engine failure, the meteorological conditions must be at or above instrument approach and landing minima for the aerodrome or such as to allow a visual approach; and
b. if engine failure occurs at any time after V1, lift-off, or encountering non-visual conditions, terrain clearance must be assured until reaching either enroute LSALT or departure aerodrome MSA.
Just Joined, I believe it does raise the take off minima to the approach minima by implication if you have to return to the same aerodrome as you are departing.
If you are going somewhere else, then 300/2 applies, but you must be able to get to LSALT or MSA if you're in the soup when the engine fails. If you have to return, then why did you depart in the first place if the approach minima are higher than 300/2??? How are you going to see to get back to the runway once you are at the minima?
Agreed it says you cannot use 300/2 if the met conditions are below the appch min, so what are you going to use instead?
Common sense should be prevailing by now.
As for a solution to the original post, my ILS 19 plates have a 220' (270' with no PEC) minima,therefore 300/2 is the correct answer anyway.
Are you sure there wasn't a reference to the 19Y being the only one available because you must have a DME for this appch (overwater, no markers) and GNSS is not permitted (different distance reference to the 19Z appch) which would limit you to the 19 LOC minima at 410' and 2.2km vis. Can't see this as a problem, though as the DME is the only difference between the Y and Z approaches and the "SACA" approved GNSS should take care of that aspect anyhoo.
Other than that, why don't you call Bob and confirm the specifics of this question?
He rarely uses anything other than Section 4.4 type a/c in his examples.
Have you got a textbook edition that has been amended since?
Check you've included all details.
7th Aug 2012, 14:58
MakeItHappenCaptain, I want to make it clear I am talking the pedantic, as it is written to the word meaning, not the logical implication.
As I wrote:
Also technically if a return to land is necessary and the approach minima is something like 900'/4.5k it does not state that anywhere that you increase the take off minima to that level, it just means that you may only use the 300'/2000m minima if the conditions are above 900'/4.5k.
I.e. You can only take off if the conditions are above the landing minima, but the take off minima does not change. Just if the conditions are below the minima you are not allowed to use the take off minima, hence the phrase 'it is a condition of the use of'.
So yes, logically the minimum conditions required to take off would be referred to as the 'take off minima' but in an over the top, legal way, the actual standard take off minima does not change.
Usually the question is phrased 'If a return to land in the case of an engine failure is required, the minimum conditions that must exist for your take off are:
1. *Whatever the approach minima is*
Which covers it anyway.
7th Aug 2012, 15:56
Hey, agreed with you, just presenting it in a way that the inevitable "Well it doesn't say exactly, so what do you do?" critics will understand.
It was a bit hard to word without making it seem like I was correcting you, but I think I achieved that pretty well. Not my intention and apologies.
8th Aug 2012, 03:45
No you did, mis-read on my part.
Good luck with your exam tik_nat!
8th Aug 2012, 08:40
Thanks everyone for your replies.