Enroute alternate required at the planning stage
Gentlemen,
Question, something that has been bothering me for awhile. I've tried google and came across some discussion on the topic on this forum but the answers seemed inconclusive.
It's about alternates. Under specific conditions we need a take off alternate. We almost always need a destination alternate( EU OPS have conditions where you don't need a destination alternate, but that's beside the scope of my question), sometimes two. If we want to reduce the contingency fuel from 5% to 3% we need an enroute alternate.
There is a table that specifies the weather that the destination alternate and 3% alternate have to comply with and that is ultimately where my question is later on.
We also need 60 minute alternates if we fly a twin(B73) but they only need to be adequate and,
If we cannot enroute, for a twin maintain at least a positive climb gradient at least 1000 ft above terrain we need to clear al terrain and divert to an alternate where a landing can be made taking into account performance and meteorological conditions.
So, to summarize, there are 5 different type of alternates. Each specifies their WX requirements.
- TO alt: you need to be able to land taking into account N-1 conditions;
- 3% ERA: you need WX according to table in EU OPS 1.297
- DEST alt: you need WX according to table in EU OPS 1.297
- 60 minute alternates which only have to be adequate according to EU OPS
- Alternates in case of engine failure over high terrain where you cannot maintain a
Positive climb gradient at at least 1000 ft above terrain, you need to be able to clear
all terrain and be able to divert to an airport where a safe landing can be made taking
Into account field conditions and WX conditions
This is all very clear to me!
However, EU OPS 1.192 mentions an enroute alternate required at the planning stage!!
Furthermore EU OPS 1.297 mentions the table that specifies the WX requirements for the following alternates; destination alternate; isolated destination alternate; 3% fuel alternate AND enroute alternate required at the planning stage.
WHAT IS MEANT BY THIS enroute alternate required at the planning stage????
- It is not the TO alternate!
- It is not the destination alternate since it is already covered in the table!
- It is not the 3% alternate since it is already covered in the table!
- It is not the TO alt since it only needs to comply with WX taking into account N-1 limitations.
- it is not the alt required according OPS 1.500 since that only requires weather reports or forecasts, or any combination thereof, and field condition reports indicate that a safe land-ing can be accomplished at the estimated time of landing.
So my questions is: what does EU OPS mean with the phrase enroute alternate required at the planning stage??
Below are copy/paste segments from the applicable regulations.
Many thanks in advance
OPS 1.192
Terminology
(a) Adequate Aerodrome. An aerodrome which the operator considers to be satisfactory, taking account of the applicable performance requirements and runway characteristics; at the expected time of use, the aerodrome will be available and equipped with necessary ancillary services such as ATS, sufficient lighting, communications, weather reporting, navaids and emergency services.
d) En-route alternate (ERA) aerodrome. An adequate aerodrome along the route, which may be required at the planning stage.
(e) 3 % ERA. An en-route alternate aerodrome selected for the purposes of reducing contingency fuel to 3 %.
Routes and areas of operation
(a) An operator shall ensure that operations are only conducted along such routes or within such areas, for which:
5. If two-engined aeroplanes are used, adequate aerodromes are available within the time/distance limitations of OPS 1.245;
OPS 1.297
Planning minima for IFR flights
(c) Planning minima for a:
destination alternate aerodrome, or
isolated aerodrome, or
3 % ERA aerodrome, or
en-route alternate aerodrome required at the planning stage
An operator shall only select an aerodrome for one of those purposes when the appropriate weather reports or fore-casts, or any combination thereof, indicate that, during a period commencing one hour before and ending one hour after the estimated time of arrival at the aerodrome, the weather conditions will be at or above the planning minima in Table 1 below.
Tabel not included!!
OPS 1.500
En-route — One engine inoperative
(a) An operator shall ensure that the one engine inoperative en-route net flight path data shown in the Aeroplane Flight Manual, appropriate to the meteorological conditions expected for the flight, complies with either subparagraph (b) or (c) at all points along the route. The net flight path must have a positive gradient at 1 500 ft above the aerodrome where the landing is assumed to be made after engine failure. In meteorological conditions requiring the operation of ice protection systems, the effect of their use on the net flight path must be taken into account
(b) The gradient of the net flight path must be positive at at least 1 000 ft above all terrain and obstructions along the route within 9,3 km (5 nm) on either side of the intended track.
c) The net flight path must permit the aeroplane to continue flight from the cruising altitude to an aerodrome where a landing can be made in accordance with OPS 1.515 or 1.520 as appropriate, the net flight path clearing vertically, by at least 2 000 ft, all terrain and obstructions along the route within 9,3 km (5 nm) on either side of the intended track in accordance with subparagraphs 1 to 4 below:
4. the aerodrome where the aeroplane is assumed to land after engine failure must meet the following criteria:
(i) the performance requirements at the expected landing mass are met; and
(ii) weather reports or forecasts, or any combination thereof, and field condition reports indicate that a safe land-ing can be accomplished at the estimated time of landing.