Multi IFR take-off minima question

[Roger Copy Ta]

I'm studying for IREX and having problems with take off minima questions.

My understanding is: for single engine IFR a/c always use 300' and 2km vis

For multi engine IFR a/c (such as OZY, not 2 pilot), OCTA with no IAP, use LSALT and 5km vis, taking into account airfield elevation.

or... if there is an IAP use the approach landing minima, taking into account airfield elevation, runway in use due wind and the possiblity of subtracting 100' with the correct QNH.

Does this change if taking off from a controlled radar aerodrome?
When would a multi engine a/c such as OZY use the 300' and 2km vis minima, if ever?

I keep getting these questions wrong and I can't see my error. If someone could please help me out with this it would be much appreciated.

[AerocatS2A]

You can use 300' and 2km if you don't intend to return to the departure airfield in the event of an emergency (engine failure for example.) With light twins having quite poor performance on one engine, most people plan to use the departure airfield as their emergency field and so the take-off minima becomes the landing minima for the most appropriate approach, or weather sufficient to allow for a visual approach if there is no IAP. The presence of ATC and controlled airspace is not directly relevant.

With that in mind, I would use the landing minima if in a single as well. So I can return if I have a partial engine failure or something.

[Chimbu chuckles]

From memory..and it's been a while since I was a IR examiner.

For single engine aircraft;

Standard Takeoff minima (300/2km) apply except where noted on the landing chart.

For 2,3 and 4 engine aircraft <5700kg MTOW, SP, no auto feather, unable to climb on one engine at 1.9% standard takeoff minima (300/2km) apply except where noted on the landing chart.

No IAL at night visual below the LSA/MSA within 3nm of the aerodrome.

Multi engine aircraft that must return to land (no departure alternate) IAL minimas or visual approach.

The actual QNH applies to landing or filing as an alternate.

Multi engine, two crew, > 5700kg MTOW. Ceiling 0', vis 800m/500m ok with runway edge lights not greater than 60m spacing and centerline lights or marking.

Radar is of no help...except to pinpoint approx where you crashed.

Hope that helps.

Editted for 'within'

[Roger Copy Ta]

Cheers guys, think I was missing the point that if you don't intend to return to the departure aerodrome (in the event of EFATO) then you use 300' and 2km... provided you have a big set of solid steel balls!
That's some crazy f@#ked up s^%t man. :eek:

[Chimbu chuckles]

It's more a matter of if you cannot return...for instance overcast at 300' and vis of 2000m..ish:E ...only available approach has a minima of 400'/1200m (CNS Rwy 15 ILS)...well you dont look likely to get back in for an emergency return but just XXnm away is an airfield where weather is comfortably above Cat 1 minimas...or, for that matter CAVOK...and you determine that in that direction there is no terrain that precludes you getting there and you have the fuel to get there on one engine...that's called a departure alternate and you can legally depart at 300/2km.:ok:

No such option then you cannot depart, in the above case, with less than 400'/1200m..or whatever it happens to be where you're at.

Another example might be departing YSBK and holding YSSY as a departure alternate...it gets you away when you might not otherwise.

Chuckles

[LUCKY-1]

RTC. Having to have several cracks at this exam I was also in your position. The qeustion is really (as per Chimbu Chuckles advises) about what are you going to plan to do if you lose one on takeoff and in the soup. There is provision in the exam in one question where you can fly over water on one engine to a major airport nearby at sea level. This answer is also correct. Think about it. Before you commit yourself to IMC, what are your planned actions should you lose one in IMC. The minmas may allow take off, but the cloud & viz may not allow an instrument approach to your departure field. Do you see what the examiner is trying to get you to consider?

Cheers Lucky

[Roger Copy Ta]

Pprune at it's finest! Good sound advice filtering down to those in need. Thanks for the great responses boys, very helpful.

Passed the exam today (90%) and nothing in the KDR about take-off minima.
Job well done all round,
Cheers