Adequate airport planning for non-ETOPS and WX minima
 

Hello,

I have recently got into a heated discussion with my colleague about the necessity of planning the enroute alternate for the purpose of our upcoming Atlantic crossing on a non-ETOPS flight. Since I don’t really have as vast of an experience as my older ops coworker, I started to doubt whether my understanding and interpretation of the EASA regulations on this subject are accurate. I’d like to point out that the company I work for does not possess the approval for ETOPS. Our COM states that “the maximum distance from an adequate airport for the flight with one engine inop is 820 NM (120min) for such and such a/c type.” The definition of the adequate aerodrome which can be found both in our COM and EASA docs states similarly that the adequate aerodrome, means an aerodrome on which the a/c can be operated, taking into account the applicable performance requirements and runway characteristics. NOTHING ABOUT THE REQUIRED WX MINIMA.

After carefully studying the AMC 20-6 and CAT.OP.MPA140 I have deduced, that for non-ETOPS operations, and at the planning stage, the weather conditions at the adequate airport which can be used for the ETP plotting do not have to meet any specific minima as it does in the case of the ERA (Dispatch minima for ERA). Keep in mind that for the purposes of this discussion and type of flight the fuel is not a factor, we are not trying to reduce the contingency down to 3%.


Therefore, after a brief explanation I’d like to ask the two following questions:

1. From a legal perspective and in light of the EU OPS rules, do I have to account for the weather at the adequate aerodromes when planning the route that allows the a/c to remain within 120 minutes from the mentioned adequate aerodromes along the route?
   
   
2. And again, from a legal perspective and in light of the EU OPS rules, do I even have to include the enroute alternate aerodrome if planning a non-ETOPS flight over, let’s say, the Atlantic?
   

I believe that in our argument there is confusion between the meaning and purpose of the adequate AD and ERA, which are clearly not the same thing. I explained that imo, we could have adequate airports planned to meet the 120 min diversion requirement but not all of them (or even none of them) have to be above the WX minima at the stage of planning the flight. I am only asking about the legality of such ops because naturally, I would think twice before releasing the a/c if all the diversion ADs along the route would forecast the wx way below the minimums. Idk maybe there's something I'm missing here. Thanks for your help and please forgive me if this is the 100th time someone asks this question. I just haven’t found any conclusive answer to this argument.

So are you ETOPS or not?

Hey, no. No, as I mentioned multiple times throughout this post, this is for non-ETOPS aircraft. Sorry if I made it sound confusing.

Have I missed something in your post ? I was always under the impression that non ETOPS had to be no more than ONE hour from an adequate airfield. Otherwise you need ETOPS approval. That’s assuming that it’s a public transport operation.

Your 120 minutes is very confusing, but not part of the question.

Yes, for normal planning (planned within distance coverable in 60 mins with the approved OEI speed) the required airports along the route need to be adequate (the definitions and requirements are available in the regulation). That's it, no pre-dispatch WX conditions to fulfill.

ERA, on the other hand, is a nominated alternate (to achieve a specific goal) and just like any other alternate fields there is a mandatory WX limit to achieve before dispatch.

In practical life there is a bit of overlay, as for longer routes beyond cca 3 hrs 30 min it is beneficial to use an ERA.

But that comes irrespective of the planning mode - ETOPS or not.

Thanks for the answer FlightDetent!

And yes, EASA has changed it back in August of 2019 for non-ETOPS. It's 120 min from an adequate airfield now (for most with MOPSC of 19 or less).


"(b) point CAT.OP.MPA.140 is amended as follows:
—
point (a) is replaced by the following:‘(a) Unless approved by the competent authority in accordance with Subpart F of Annex V (Part-SPA), the operator shall not operate a two-engined aeroplane over a route that contains a point further from an adequate aerodrome, under standard conditions in still air, than the appropriate distance for the given type of aeroplane among the following:

(1) for performance class A aeroplanes with a maximum operational passenger seating configuration (MOPSC) of 20 or more, the distance flown in 60 minutes at the one-engine-inoperative (OEI) cruising speed determined in accordance with point (b);

(2) for performance class A aeroplanes with an MOPSC of 19 or less, the distance flown in 120 minutes or, subject to approval by the competent authority, up to 180 minutes for turbojet aeroplanes, at the OEI cruising speed determined in accordance with point (b);"

source: and I can't post links yet... but it's in Commission Implementing Regulation (EU) 2019/1387

MOPSC was the key, I'm enlightened now. Thanks for the response.

I think the worst-case scenario is a flight that follows a coastline. With our 60 minutes-equivalent rule if you're overhead a fogged airport (that you know about before, legally) you are 2x 60 minutes distance (still air) from the two closest available airports (ahead and behind). 900 NM for us, long way.

It doesn't make sense, but:

Suitable (ETOPS) = weather required
Adequate (to keep you non-ETOPS) = no weather required

At least that's the way it's written. So you could fly from the the Middle-East to UK, non-ETOPS, with every airport “weathered in”, as long as they were open.

Common-sense and airmanship apparently doesn’t have anything to do with it.

Good luck.

Common sense suggests such is yet to happen. Airmanship requires an understanding the risk in aviation is greater than absolute zero, which is okay as long as it is managed reasonably.

The non-etops rule assumes that on a day of
- a real engine failure, single side
- to an aeroplane flying non-etops over austere places
- which happens at the most critical point of the route
- on a day when the closest field is available but not suitable

==== there's at least one pure soul worth saving onboard, so that ======
+ the remaining engine will not fail from independent causes in less than 2 hours (for the 60 mins-distance rule)

The four 'minus' probabilites above multiply, resulting in an effective nil chance of being that unlucky. Even if, then frankly engines don't fail in the cruise much at all. Take-of and climb cases are well covered by the TKOF ALTN requirement, the same principle applies for G/A at the other end. Applies for the remaining engine as well as for the first one to fail.