Enroute Alternate Weather Requirements
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Whoa guys and girls!
Henry - you have actually 'misquoted' EU OPS! If you look at (c) the "required at the planning stage" is on the same line as (4) En-route alternate aerodrome. You have dropped it a line. NORMALLY an 'en-route alternate' is not specified/used by a company. When it is, those weather restrictions apply. Hopefully knickers untwisted?
Have a look at 1.1.92 ''adequate' (a) [and note the slight difference for ETOPS 'adequate']
Henry - you have actually 'misquoted' EU OPS! If you look at (c) the "required at the planning stage" is on the same line as (4) En-route alternate aerodrome. You have dropped it a line. NORMALLY an 'en-route alternate' is not specified/used by a company. When it is, those weather restrictions apply. Hopefully knickers untwisted?
Have a look at 1.1.92 ''adequate' (a) [and note the slight difference for ETOPS 'adequate']
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I've quoted: FAA, TC, CAAS and several company OPS manuals. I also included the references.
Henry was kind enough to quote EU-OPS.
The general point that you seem to be missing is this:
All flights must operate in a safe manner, and therefore have a place to go in the event that things don't go as expected (Common sense amongst other things).
Some regulations include this requirement. Some don't. Many - no most -western Operators include a similar requirement.
Non-etops flights (When required) have the same weather requirement for enroute alternates (weather.....1 hour before ETA to 1 hours after...etc), along with destination alternates, take-off alternates, etc. The difference is 60 mins, versus 120,180, etc, etc for ETOPS.
Also, there is the inclusion of the term "Suitable" with ETOPS, which is not included in Non-ETOPS. Non-ETOPS simple says, "Adequate Airport...with "weather above landing minima..."
Now, if your ME airline believes that flying "10000 miles" with no "Adaquate Enroute Airport" with "weather above landing minima" is acceptable, then rest assured I'll be avoiding that airline!
Big reminder! We are talking about "Planning" not about "In-flight". And, as BOAC stated
Henry was kind enough to quote EU-OPS.
The general point that you seem to be missing is this:
All flights must operate in a safe manner, and therefore have a place to go in the event that things don't go as expected (Common sense amongst other things).
Some regulations include this requirement. Some don't. Many - no most -western Operators include a similar requirement.
Non-etops flights (When required) have the same weather requirement for enroute alternates (weather.....1 hour before ETA to 1 hours after...etc), along with destination alternates, take-off alternates, etc. The difference is 60 mins, versus 120,180, etc, etc for ETOPS.
Also, there is the inclusion of the term "Suitable" with ETOPS, which is not included in Non-ETOPS. Non-ETOPS simple says, "Adequate Airport...with "weather above landing minima..."
Now, if your ME airline believes that flying "10000 miles" with no "Adaquate Enroute Airport" with "weather above landing minima" is acceptable, then rest assured I'll be avoiding that airline!
Big reminder! We are talking about "Planning" not about "In-flight". And, as BOAC stated
When it is, those weather restrictions apply
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Jimmy - it matters not what YOUR OM says except for you - the question by tayyarci was about REGULATIONS. EU-OPS do NOT require weather to be consdiered at en-route points. (Note I did not say 'en-route alternates').
This does not mean that we are all flying around over 8/8 fog ignoring the weather and not thinking about where to go! It was about what is REQUIRED.
This does not mean that we are all flying around over 8/8 fog ignoring the weather and not thinking about where to go! It was about what is REQUIRED.
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The original question was not referring to regulations, else this would be much simpler.
He is looking for a requirement, and with the reference to the difference for four engine aircraft, it is easy to assume that he's referring to Air Carrier Operations. In which case, the FOM supersedes the Regulations PROVIDED that they are more restrictive than the applicable Reg. If I assumed his question correctly, his companies FOM is the approved source for requirments, thus the answer lies there.
I looked in three separate FOM's from other Air Carriers and found very similar requirements.
Otherwise, the only clearly stated "Regulation" is that from the US FAA (FAR121), which ONLY applies to Air Carriers. FAR 91 (General Aviation) does not include such a requirement.
on a non ETOPs route for a twin engine operation what's the weather requirements for an enroute alternate airport, as far as I remember there's no requirement but I cannot find where it would be written
and is there any difference for this rule for a 4 engine operation
and is there any difference for this rule for a 4 engine operation
I looked in three separate FOM's from other Air Carriers and found very similar requirements.
Otherwise, the only clearly stated "Regulation" is that from the US FAA (FAR121), which ONLY applies to Air Carriers. FAR 91 (General Aviation) does not include such a requirement.
Last edited by Jimmy Do Little; 15th Jul 2009 at 16:56.
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Geez - this is hard going!
1) The OP is UK based therefore EUOPS applies
2) NB The OP 'found' the answer in JAROPS (no weather requirement) #2 thus OP was looking for REGULATORY
3) Your #3 refers to s/e cruise times OVER 60 mins. (see wizofoz #6) therefore not applicable.
Shame we didn't 'bed' this one at #13
1) The OP is UK based therefore EUOPS applies
2) NB The OP 'found' the answer in JAROPS (no weather requirement) #2 thus OP was looking for REGULATORY
3) Your #3 refers to s/e cruise times OVER 60 mins. (see wizofoz #6) therefore not applicable.
Shame we didn't 'bed' this one at #13
Now, if your ME airline believes that flying "10000 miles" with no "Adequate En-route Airport" with "weather above landing minima" is acceptable, then rest assured I'll be avoiding that airline!
Kindly name the airlines who's FOMs you checked and quote the requirements for weather minima non-ETOPs from them. (happy to reciprocate afterwords). You've shown a marked inability to interpret manuals so far- I'd be surprised if it didn't extend to your claim that most airlines impose these restrictions over and above the regs.
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I stand corrected. Should have been 3.4.6 (b) Alternate Airports - Non-ETOPS, which includes the statement "...No more than 60 minutes..."
Nonetheless, this is a Company Requirement. Again, the definitive answer will be in his companies FOM, and it is quite possible that there is NO requirement in that manual.
Nonetheless, this is a Company Requirement. Again, the definitive answer will be in his companies FOM, and it is quite possible that there is NO requirement in that manual.
Last edited by Jimmy Do Little; 17th Jul 2009 at 10:37.
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Interesting subject, clearly this is a grey area in the regulations.
Since most airlines just copy these regulations into their manuals, it's up to the pic to accept a route or not regarding weather.
Since most airlines just copy these regulations into their manuals, it's up to the pic to accept a route or not regarding weather.
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Thank you Mac - some daylight!
As a man (not God) said to me once - "That's why God put the 4th stripe on your shoulders" (mind you, a bit OTT, no?)
Originally Posted by boac
Jimmy - it matters not what YOUR OM says except for you - the question by tayyarci was about REGULATIONS. EU-OPS do NOT require weather to be considered at en-route points. (Note I did not say 'en-route alternates').
This does not mean that we are all flying around over 8/8 fog ignoring the weather and not thinking about where to go! It was about what is REQUIRED.
This does not mean that we are all flying around over 8/8 fog ignoring the weather and not thinking about where to go! It was about what is REQUIRED.
bfisk,
I'm not sure that he did, but that has also been addressed here. Under JAROPS, to reduce contingency from 5% to 3% one must have an ADEQUATE airport (thus we no attached weather requirements) lying within a circle whose diameter is 20% of the route distance (a minimum of 50miles) centred 75% alond the route.
Why adequate rather than suitable in this case? Dunno, but thems the rules.
I'm not sure that he did, but that has also been addressed here. Under JAROPS, to reduce contingency from 5% to 3% one must have an ADEQUATE airport (thus we no attached weather requirements) lying within a circle whose diameter is 20% of the route distance (a minimum of 50miles) centred 75% alond the route.
Why adequate rather than suitable in this case? Dunno, but thems the rules.
Hmm, see this is still rumbling on. For what it's worth my answer to the original question (for EU-Ops, non ETOPS) is that IF an en-route alternate is required because you need to reduce your contingency fuel below 5% of trip due to performance/payload problems OR you are using the 3% ERA reduction procedure (they are different things for different situations) then it must be "adequate" and permit a landing to be made at ETA +/- 1 hour using the standard alternate planning minima.
For a twin on a non-ETOPS flight you must also remain within 1 hours SE flying time of an adequate aerodrome, the definition of which does not include any weather criteria.
For a twin on a non-ETOPS flight you must also remain within 1 hours SE flying time of an adequate aerodrome, the definition of which does not include any weather criteria.
Last edited by Max Angle; 21st Jul 2009 at 18:53.
Hi Max,
My FOM simply says an airport must be "Available" and I know the common interpretation of that is "Adequate" (No weather requirements). Do you have a reference that is different? I'd be very interested to know and would have a serious look at our regs.
One thing though, I think people get caught up and think that "Adequate Airport" is a term soley associated with ETOPS planning. It isn't. It PRE-DATES the invention of ETOPS, and the fact that many routes couldn't meet the "Adequate with 60mins SE flight time" rule was why ETOPS was invented in the first place.
My FOM simply says an airport must be "Available" and I know the common interpretation of that is "Adequate" (No weather requirements). Do you have a reference that is different? I'd be very interested to know and would have a serious look at our regs.
One thing though, I think people get caught up and think that "Adequate Airport" is a term soley associated with ETOPS planning. It isn't. It PRE-DATES the invention of ETOPS, and the fact that many routes couldn't meet the "Adequate with 60mins SE flight time" rule was why ETOPS was invented in the first place.
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Wiz - I do not have EU-OPS immediately to hand, but JAR OPS 1.2.97 (c) and table have that. It also refers to 'en-route alternate when required at the planning stage' but I have never experienced that requirement on any non-ETOPS flight. Choice of non-ETOPS ERAs has always been left to the operating crew in flight.
Edit: Got the T-shirt - same ref in EU-OPS surprise surprise!
Edit: Got the T-shirt - same ref in EU-OPS surprise surprise!
The only reason to select an en-route alternate on a non-etops flight is to allow the reduction of contingency fuel below 5% of trip. You are effectively re-dispatching the flight overhead the en-route alternate or abeam it at suitable point thus enabling you to reduce the contingency to 5% of the trip from the decision point to the destination rather than 5% of the whole trip fuel. We use it quite a bit on routes that stretch a 320 or 321 to the limit such as Tehran-Heathrow, being able to lose 400kg of contingency fuel can make all the difference
As BOAC says JAR 1.297, which is available if you google it, says that at an en-route alternate has the same planning minima as a destination alternate, the rules and reference are the same under EU-Ops as far as I can tell. Quite agree that "adequate" is not simply an ETOPS term. I guess the difference with an en-route alternate is that there is a real chance of ending up there and you have to dispatch knowing that is will be available to you should you need it.
As BOAC says JAR 1.297, which is available if you google it, says that at an en-route alternate has the same planning minima as a destination alternate, the rules and reference are the same under EU-Ops as far as I can tell. Quite agree that "adequate" is not simply an ETOPS term. I guess the difference with an en-route alternate is that there is a real chance of ending up there and you have to dispatch knowing that is will be available to you should you need it.
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MA - there is still a puzzle (as always) in the regs as they distinguish between a 3% alternate and an 'en-route alternate'. Heaven knows . I think I'll just ignore it.
As far as I can tell the planning minima are the same, its their allowable location and terms of use that are different.
A 3% ERA can be used on any flight to reduce the contingency fuel to 3% of total trip fuel rather than 5% thus allowing a little less fuel to be loaded and saving (a small amount) on the burn as well as perhaps allowing a larger payload. Copied from our manual: "The en-route alternate should be located within a circle having a radius equal to 20% of the total flight plan distance, the centre of which lies on the planned route at a distance from the destination of 25% of the total flight plan distance, or at least 20% of the total flight plan distance plus 50 nm, whichever is greater, all distances are to be calculated in still air conditions." Fortunately it's easier in practice as the company have worked them out for all the routes that can benefit. It's up to the skipper on the day as to whether they want to use it or not.
There is also the option to reduce to minimum contingency (250kg on a 321) in which case the en-route alternate must be within 150nm of track and be at least 30 minutes flying time from the destination but obviously you need it fairly close to destination as you don't want 5% of the remaining trip fuel to be more than 250kg. This option can only be used if you unable to load the normal 5% (or 3% if are using that procedure) due to a performance or payload restriction.
In both cases the airfield must be above the planning minima for +/- 1 hour of ETA.
A 3% ERA can be used on any flight to reduce the contingency fuel to 3% of total trip fuel rather than 5% thus allowing a little less fuel to be loaded and saving (a small amount) on the burn as well as perhaps allowing a larger payload. Copied from our manual: "The en-route alternate should be located within a circle having a radius equal to 20% of the total flight plan distance, the centre of which lies on the planned route at a distance from the destination of 25% of the total flight plan distance, or at least 20% of the total flight plan distance plus 50 nm, whichever is greater, all distances are to be calculated in still air conditions." Fortunately it's easier in practice as the company have worked them out for all the routes that can benefit. It's up to the skipper on the day as to whether they want to use it or not.
There is also the option to reduce to minimum contingency (250kg on a 321) in which case the en-route alternate must be within 150nm of track and be at least 30 minutes flying time from the destination but obviously you need it fairly close to destination as you don't want 5% of the remaining trip fuel to be more than 250kg. This option can only be used if you unable to load the normal 5% (or 3% if are using that procedure) due to a performance or payload restriction.
In both cases the airfield must be above the planning minima for +/- 1 hour of ETA.
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I'm pretty familiar with the 3% jobbie. It is the other 'ERA' referred to of which I have no experience. I'm guessing it is just there in case a company, for some reason, wishes to nominate an ERA, although why escapes me.