Enroute Alternate Weather Requirements

[tayyareci]

Hello everybody,

If anyone can give me a reference for this question I really appreciate I am unable to find it so far,

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

thanks

[tayyareci]

found the answer

“JAR-OPS 1.245
(a) Unless specifically approved by the Authority […], an operator shall not operate a two-engined aeroplane over a route which contains a point further from an adequate aerodrome than the distance flown in 60 minutes at the [approved] one-engineinoperative cruise speed”.

thanks

[Jimmy Do Little]

on a non ETOPs route for a twin engine operation what's the weather requirements for an enroute alternate airport

Does the following help?

3.4.6 Alternate Airports

1. An aeroplane shall not be released unless the required take-off, destination and alternate airports, including en route alternate airports to be used in the event of a system failure which requires a diversion, are listed in the operational flight plan, (e.g. on board copy of computer flight plan).
2. Suitable en route alternates are also required to be identified, listed and provided to the crew with the most up to date information (e.g. airport data, facilities, weather, etc.) as part of the dispatch release for all cases where the planned route of flight contains a point (Note: appendix "B" includes the word "no" a this point) more than 60 minutes flying time at the approved one-engine-inoperative cruise speed from an adequate airport. Since these en route alternates serve a different purpose than the destination airport and would normally be used only in the event of an engine failure or the loss of a primary airframe system, an airport may not be listed as an en route alternate unless:
   1. The landing distances required as specified in the Aircraft Flight Manual for the altitude of the airport, for the runway expected to be used, taking into account wind conditions, runway surface conditions, and aeroplane handling characteristics, permit the aeroplane to be stopped within the landing distance available as declared by the airport authorities and computed in accordance with the applicable regulations;
   2. The airport services and facilities are available and adequate for the operator's approved approach procedure(s) and operating minima for the runway expected to be used;
   3. The latest available forecast weather conditions for a period commencing one hour before the established earliest time of landing and ending one hour after the established latest time of landing at that airport, are equal to or exceed the authorized weather minima for en route alternate airports in appendix B; (Standard Alternate Requirements).
   4. For the same period, the forecast cross wind component for the intended landing runway, including gusts, is less than the maximum permitted cross wind for a single engine landing. Where no single engine demonstrated cross wind value exists, 80% of the all engine demonstrated value will be used.

[Wizofoz]

We are getting a few terms mixed up here, I feel.

What Jimmy has quoted is the requirements for an aerodrome to be considered a Suitable airport. An aircraft on an ETOPs flight must always be within the ETOPs maximum threshold (120, 180 or 207 mins at the pre-determined, single engine diversion speed as appropriate) at any time that it is more then 60mins flight time from an Adequate airport.

There are no weather requirements for an airport to be considered an Adequate airport.

I think what tayareci might be referring to a Fuel en-route alternate, required to reduce contingency fuel from 5% to 3%. Such an aerodrome need only meet the requirements of an Adequate airport, and as such has no weather requirements.

[Jimmy Do Little]

wizofox... True and correct, but

on a non ETOPs route for a twin engine operation what's the weather requirements for an enroute alternate airport

[Wizofoz]

Jimmy-

If you are non-ETOPs the weather requirements for en-route alternates are nil, as you only have to consider adequate airports.

From your quote-

for all cases where the planned route of flight contains a point more than 60 minutes flying time at the approved one-engine-inoperative cruise speed from an adequate airport.

If you are always LESS then 60mins from an adequate airport, you are non-ETOPS. Adequate airports have no weather requirements.

[Jimmy Do Little]

I think the confusion here is in the difference between, Alternate "Planning" and Alternate "Actual".


----------------------

From my companies FOM (Per applicable Regulations)

Definitions from FOM... (Non-ETOPS. ER ops covered in separate section)

Alternate aerodrome : An aerodrome to which an aircraft may proceed when it becomes either impossible or inadvisable to proceed to or to land at the aerodrome of intended landing.

Alternate aerodromes include the following :
Take-off alternate : An alternate aerodrome at which an aircraft can land should this become necessary shortly after take-off and it is not possible to use the aerodrome of departure.

En-route alternate : An aerodrome at which an aircraft would be able to land after experiencing an abnormal or emergency condition while en route.

Destination alternate : An alternate aerodrome to which an aircraft may proceed should it become impossible or inadvisable to land at the aerodrome of intended landing.


Duties and Responsibilities....
....Ensure that the provisions specified in the Operations Manual(s) in respect of fuel, oil and oxygen requirements, minimum safe altitudes, aerodrome operating minima and availability of alternate aerodromes, where required, can be complied with for the planned flight;

Pilots are responsible for monitoring weather of destination airport, enroute
alternates (if applicable), destination alternates(if applicable) (VOLMET or other appropriate service) NOTAM’s etc, during flight to ensure that there have been no changes which may affect the safety of the operation.

In the event of changed conditions at the destination or any alternate airport due to weather or some other factor the commander must take the responsibility as to the appropriate course of action.

Remember, there is a difference between "Suitable Enroute Alternate" and "ETOPS Alternate", or whatever your company (authority) decides to call it. (See Boeing Reference 22 Oct 2005).

My door is wide open for further discussion, as these things are often misunderstood.

[Wizofoz]

Sure.

Nothing you've quoted indicates any requirement for en-route alternates to conform to any particular weather minima if the flight is non- ETOPS.

Can you quote anything that would, say, cause a re-route or cancellation to be required because any or all en-route aerodromes, within the 60 minute ETOPS threshold, was below any particular weather minima? Yes, you should know what the weather is like at aerodromes on your route, so you know whether they are available to divert to, but there is no planning OR en route minimum weather that they have to conform to to commence and continue the flight, as long as the flight is non-ETOPs.

You can fly 10 000 miles over nothing but aerodromes that are 0/0 in fog, as long as you are never more than 60 minutes from an Adequate Aerodrome, the definition of which does not include any weather requirements.

[Jimmy Do Little]

Can you quote anything that would...

Everything above is simply cut and pasted from various relevant manuals, etc.

You can fly 10 000 miles over nothing but aerodromes that are 0/0 in fog, as long as you are never more than 60 minutes from an Adequate Aerodrome, the definition of which does not include any weather requirements.

Only if that aircraft actually had a 10 000 mph S/E cruise speed.

More Regulatory quotes:.....

Take off alternate is required if weather below landing minima of the airport:

• T/O alternate must be within 60 minute at S/E inop cruise
• Weather at alternate airport must be above alternate minima at time of

departure and at ETA for alternate.....

Blows the 10000 mile idea.

Alternate is an Alternate. All need some planned weather requirement to be NOMINATED on a flight plan (ATC or CFP).

ETOPS is simply better defined, and the regulations are condensed.

If you could quote ANY regulations or authorized reference, I'd be happy to consider.

[Wizofoz]

Sorry Jimmy, but you are simply wrong. There is no requirement for an Adequate Airport to conform to any weather minima, and no requirement OTHER than an aircraft be within sixty minutes of an adequate airport at every point on the flight.See Tayaracie's second post.

Destination and Takeoff alternates have weather requirements. Suitable Airporst (only relevent to ETOPS) have weather requirements. Adequate airports don't. The very Regs you have quoted say this, but you are miss-interpreting them.

Some cut'n'pasting of my own-

1) Adequate - an adequate airport is an airport, which the operator and TCCA consider to be adequate, having regard to the performance requirements applicable at the expected landing weight. In particular, it should be anticipated that at the expected time of use:
the airport will be available, and equipped with the necessary ancillary services, such as ATS, lighting, communications, weather reporting, navaids and emergency services; and
at least one approach aid will be available for an instrument approach.


2) Suitable - a suitable airport is an adequate airport with weather reports, forecasts or combination thereof, indicating that the weather conditions will be at or above minima as specified Appendix B of this document, and field condition reports indicate that a safe landing can be accomplished during the period of intended operation.

Note that there are no weather requirements for an Adequate aerodrome.

You must remain within 60 mins flight time of an Adequate aerodrome, unless you have approval to operate ETOPs.

Now please supply one quote which says you must stay within 60mins of a Suitable aerodrome.

[Jimmy Do Little]

I agree, there is no legal requirement (Government, authority, etc) with each country (Some do) , but MOST FOM will include it, thus making it legal for their operations.



I also clearly stated earlier that my above references were FOM / AOC references.

---------------------------------------------

USE OF ADEQUATE AIRPORTS FOR NON-ETOPS FLIGHTS

Normally weather for adequate airports are not required except:

- where the departure airport is below landing minima, a useable adequate airport must have a valid forecast from 30 mins prior to earliest time of use to 30 mins after latest time of use.

PRE-FLIGHT (non-ETOPS) and in the non-ETOPS segments of an international flight there must be an adequate airport above the landing minima within 60 min / 405 nm (180 min / 1200 nm ETOPS A/C) of the A/C for the entire route. This is a company (not regulatory) requirement to make sure that enroute airports are available for use. MEL reductions in ETOPS diversion distances do not affect this requirement (ETOPS affecting MELs apply to ETOPS flights).

INFLIGHT, there is no legal requirement to monitor/maintain adequate airport weather above landing minima. Airmanship dictates general airport proximity and associated weather awareness.


Again, Planning (Pre-Flight) and actual (In flight). There is a difference.

The original question....

on a non ETOPs route for a twin engine operation what's the weather requirements for an enroute alternate airport,

answer that I have in FOM (approved by local authority)

there must be an adequate airport above the landing minima within 60 min / 405 nm ...of the A/C for the entire route

R T F Q


As a side note:

...a suitable airport is an adequate airport with weather reports, forecasts or combination thereof, indicating that the weather conditions will be at or above minima as specified...

...there must be an adequate airport above the landing minima...

...by definition, implies a "Suitable" Airport.

[Wizofoz]

OK, I see that your company has a requirement over and above the regulatory requirements. That's fine (but things would have been sped up if you'd indicated it was a company thing, not a regulation), but I can assure you it is not the case with "most' airlines, at least not those operating under JAR.

I've worked for a total of 5 Airlines. An Australian major, a Japanese operator, A European Charter company, A European Lo-Co and now a large ME based international which complies with JAR.

None of them, nor, as far as I am aware, the likes of BA, Lufthansa, VA etc have any requirements over and above the regulations.


The OP asked what the weather requirements were for non-ETOPS en-route alternates. From a regulatory standpoint, and for the actual operation of most airlines, there ARE none, planning or otherwise.

[Jimmy Do Little]

Have worked for some of the same 5 major operators (ETOPS and NON-ETOPS). All had a similiar requirements in their FOM's, albiet you had to dig deep in the books to find.

Time to put this one to bed.

Cheers

[0-8]

Direct from our Ops Manual (Large European operator):

NON-ETOPS Operation

The route must remain within 60 minutes of an Adequate airfield.
Note, that for the purposes of 'Adequate' the airfield does not have to
meet ANY weather criteria, but must meet the definition of an
Adequate airfield in Ops Manual A Section 8.6.2.1.

[Jimmy Do Little]

Depends on your company I suppose.....

Reminds me of a quote from an Unknown source....

"You learn to fly in a few hours, it takes years to learn when NOT to fly"
--------------------------

Incidentally... From the US FAR's (FAA Regulations)

Sec. 121.191

a) No person operating a turbine engine powered transport category airplane ....

2) The net flight path allows the airplane to continue flight from the cruising altitude to an alternate airport where a landing can be made ...where the airplane lands after an engine fails.......

b) For the purposes of paragraph (a)(2) of this section, it is assumed that--
(1) The engine fails at the most critical point en route;....

5) The alternate airport is specified in the dispatch or flight release and meets the prescribed weather minimums; and ....

[Henry VIII]

Sorry guys, I guess it’s time to refer to rules regardless of each single company ops manual.

EU-OPS 1.297 (C) says :

[(c) Planning minima for a:

(1) Destination alternate aerodrome,
(2) Isolated aerodrome,
(3) 3% ERA Aerodrome,
(4) 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 forecasts, 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.]

Table 1 Planning minima – [Destination
alternate aerodrome, isolated destination
aerodrome, 3% ERA and en-route alternate
aerodrome]
Type of approach------------Planning Minima
Cat II and III-------------------Cat I (Note 1)
Cat I-----------------------------Non-precision (Notes 1 & 2)
Non-precision----------------Non-precision (Notes 1 & 2)
------------------------------------plus 200 ft/1 000 m
Circling-------------------------Circling

Note 1 RVR.
Note 2 The ceiling must be at or above the MDH.


EU-OPS 1.297 (D) details the ETOPS en-route planning minimas.

Regards

[Jimmy Do Little]

[(c) Planning minima for a:

(1) Destination alternate aerodrome,
(2) Isolated aerodrome,
(3) 3% ERA Aerodrome,
(4) 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 forecasts, 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.]

Thank you Henry. I think I've been saying this all along.

[Wizofoz]

EU-OPS 1.297 (D) details the ETOPS en-route planning minimas.

No, you haven't. The En-Route alternate specified in Henrys post refers to an ETOPS Suitable airport, not a non-ETOPs adequate

5) The alternate airport is specified in the dispatch or flight release and meets the prescribed weather minimums;

The alternate YOU are refering to is a DESTINATION alternate, not an en-route one.

A company may choose to exceed the regulations in any way it chooses, but the regulations are as I and others have outlined to you.

My "10 000 Mile" Idea was correct under the regs and most airlines practices.

[Jimmy Do Little]

Check it again...

EU-OPS 1.297 (C) says :.... (Note "C")


EU-OPS 1.297 (D) details the ETOPS en-route planning minimas. (Note "D")

As I stated so many times earlier. It's about "Planning" and "Inflight". Eitherway, enroute alternate is typically required, and weather must be ABOVE landing minima during the "Planning" phase of flight.


Incidently. The same applies for ETOPS, however those rules include the term "Suitable". However, if during "Planning" an airport defined as "Suitable" was later (During the ETOPS portion of the flight) degraded to Adaquate, a reroute to non-etops would not be required - amongst other things (Fuel when depressurized, etc, etc)


Again, the question refered to is NON-ETOPS.


I think Henry (and Oldsmokey in a previous forum) was pointing out that you may be wrong. I'll leave it up to them to confirm either case.

[Wizofoz]

Eitherway, enroute alternate is typically required, and weather must be ABOVE landing minima during the "Planning" phase of flight.

You have not produced any supporting documents for this, except for your companies individual procedures, and have had several shown to you that contradict you. You even said so yourself, but now seem to have changed your mind.