Instrument Departures

October 16th, 2010

The previous post has got lost somewhere deep down in my blog. This topic is quite controversial and in my (somewhat humble) opinion quite important. So I’m going to post another one just to see if anyone out there in cyberspace can post a more meaningful reply.

JAR-OPS 1.230 Instrument departure and approach procedures

(a) An operator shall ensure that instrument departure and approach procedures established by the State in which the aerodrome is located are used.

(b) Notwithstanding sub-paragraph (a) above, a commander may accept an ATC clearance to deviate from a published departure or arrival route, provided obstacle clearance criteria are observed and full account is taken of the operating conditions. The final approach must be flown visually or in accordance with the established instrument approach
procedure.

(c) Different procedures to those required to be used in accordance with sub-paragraph (a) above may only be implemented by an operator provided they have been approved by the State in which the aerodrome is located, if required, and accepted by the Authority.

The part “to deviate from a published departure or arrival route, provided obstacle clearance criteria are observed and full account is taken of the operating conditions” clearly indicates that you can not deviate in IMC where clearance from obstacles could not be guaranteed. And if you are below MSA (or MRA), the only time you could guarantee obstacle clearance is if you are following a published track.

The same paragraph exists in UAE CAROPS (even with the same number) and a very similar paragraph exists in the Namibian CARs and the content is implied by the entire PANS OPS Section 3 Departure Procedures. The entire PANS OPS II goes into great detail explaining the calculations involved in determining the compliance with terrain avoidance for departures – none of which anyone could be expected (neither pilot or ATC) to complete on departure.

If a country does not have departure procedures then the airport must comply with the omnidirectional departure requirements, that is – there are no obstacles in the departure which prevent an omni directional departure at 3.3%.

Many pilots believe you can depart in IMC without a departure procedure. In fact in some countries, it is a routinely done and no one seems to think there is any problem with it.

The whole essence of PANS Ops II is to define how to construct safe tracks for pilots to follow when they are below the applicable MSA (that means also MRA if you don’t have a precision radar service!).

If you were allowed to fly around below MSA (or MRA) without a published track, wouldn’t you be allowed to do it at all times? I mean what is the difference between being below MSA on arrival or on departure except the direction the nose is pointing? (The mountains hurt just as much when you hit them on a climb as they do when you hit them on a decent!)

Besides from that, when we look at relative costs, if you have gone to the expense of establishing and maintaining an instrument approach procedure, it cost very little extra to publish a departure procedure, and if you haven’t then it’s simple to apply the same weather minimums for arrival and departure, VMC below MSA.

Again the only time the pilot/operator is responsible for his/her own terrain clearance is in VMC or in an emergency.

I think this sums it up fairly nicely, but I am sure I will get some variations of interpretations on this paragraph, since it does not say “where one exists” but nor does it say “at all times” but lets get some debate on this!

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