Diverting to non-planned alternate
Thread Starter
Joined: Oct 2012
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From: Perth
Diverting to non-planned alternate
Hi, just a general question about alternates in EASA land.
Flying a light turboprop, one of the routes I fly goes from A to B to C.
Leg A-B is just over an hour, while leg B to C is under 10 minutes.
Neither airport B or C have TAFs, so I need to have two alternates. If we have a full flight on the first leg, I cannot use A as an alternate (too far away), so we use airports D and E, which we do not have any handling at.
If I fly leg B to C, and decide to divert, am I obligated to choose between D and E, or can I divert to B, even though it is not in my atc flight plan? B is much more practical, and even though weather is generally the same at B and C, B has an ILS, so there is a good chance I would be able to land at B. Would I need to plan extra fuel for that? If I go with min fuel according to flight plan, choosing B would rule out at least one of the other alternates.
By the way, this is really only theoretical. Both airport B and C issue METARS, and we wouldn't really depart B unless we knew we could get into C.
As a secondary question. As airport C is so close to B. Would I actually require two alternates assuming METAR weather is good? I know there isn't technically a forecast, but as flight time is so close, could the METAR be considered the weather we will get on arrival?
Flying a light turboprop, one of the routes I fly goes from A to B to C.
Leg A-B is just over an hour, while leg B to C is under 10 minutes.
Neither airport B or C have TAFs, so I need to have two alternates. If we have a full flight on the first leg, I cannot use A as an alternate (too far away), so we use airports D and E, which we do not have any handling at.
If I fly leg B to C, and decide to divert, am I obligated to choose between D and E, or can I divert to B, even though it is not in my atc flight plan? B is much more practical, and even though weather is generally the same at B and C, B has an ILS, so there is a good chance I would be able to land at B. Would I need to plan extra fuel for that? If I go with min fuel according to flight plan, choosing B would rule out at least one of the other alternates.
By the way, this is really only theoretical. Both airport B and C issue METARS, and we wouldn't really depart B unless we knew we could get into C.
As a secondary question. As airport C is so close to B. Would I actually require two alternates assuming METAR weather is good? I know there isn't technically a forecast, but as flight time is so close, could the METAR be considered the weather we will get on arrival?
Joined: Jan 2017
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From: joburg
The planning and requirements for alternates are a dispatch requirement.
once you are airborne you can divert to any suitable airport, regardless of what your dispatch alternates were.
They're different phases of the flight process.
As for the second question, would you be comfortable standing in front of a judge and explaining your actions? Makes the decision fairly easy
once you are airborne you can divert to any suitable airport, regardless of what your dispatch alternates were.
They're different phases of the flight process.
As for the second question, would you be comfortable standing in front of a judge and explaining your actions? Makes the decision fairly easy
Only half a speed-brake
Joined: Apr 2003
Posts: 4,459
Likes: 136
From: Commuting not home
At least partially:
METARS are acceptable in lieu of forecast, keep digging for the specific rules when and how. Which probably solves most of your dilemmas.
ALTN airports as filed are not visible to the ATC controllers who are supervising your flight. You can go wherever you like although in their helpful wisdom they might call that field whether or not you will be accepted there. In a similar fashion, for planning: There's no such thing as formal dispatch release document listing the airport you are authorised to use on the day. CMD's responsibility.
Additional interesting knowledge is to review what "TREND type landing forecast" is, I remember too vaguely to type straight away.
METARS are acceptable in lieu of forecast, keep digging for the specific rules when and how. Which probably solves most of your dilemmas.
ALTN airports as filed are not visible to the ATC controllers who are supervising your flight. You can go wherever you like although in their helpful wisdom they might call that field whether or not you will be accepted there. In a similar fashion, for planning: There's no such thing as formal dispatch release document listing the airport you are authorised to use on the day. CMD's responsibility.
Additional interesting knowledge is to review what "TREND type landing forecast" is, I remember too vaguely to type straight away.
Joined: Mar 2012
Posts: 2,605
Likes: 154
From: Having a margarita on the beach
Hi, just a general question about alternates in EASA land.
Flying a light turboprop, one of the routes I fly goes from A to B to C.
Leg A-B is just over an hour, while leg B to C is under 10 minutes.
Neither airport B or C have TAFs, so I need to have two alternates. If we have a full flight on the first leg, I cannot use A as an alternate (too far away), so we use airports D and E, which we do not have any handling at.
If I fly leg B to C, and decide to divert, am I obligated to choose between D and E, or can I divert to B, even though it is not in my atc flight plan? B is much more practical, and even though weather is generally the same at B and C, B has an ILS, so there is a good chance I would be able to land at B. Would I need to plan extra fuel for that? If I go with min fuel according to flight plan, choosing B would rule out at least one of the other alternates.
By the way, this is really only theoretical. Both airport B and C issue METARS, and we wouldn't really depart B unless we knew we could get into C.
As a secondary question. As airport C is so close to B. Would I actually require two alternates assuming METAR weather is good? I know there isn't technically a forecast, but as flight time is so close, could the METAR be considered the weather we will get on arrival?
Flying a light turboprop, one of the routes I fly goes from A to B to C.
Leg A-B is just over an hour, while leg B to C is under 10 minutes.
Neither airport B or C have TAFs, so I need to have two alternates. If we have a full flight on the first leg, I cannot use A as an alternate (too far away), so we use airports D and E, which we do not have any handling at.
If I fly leg B to C, and decide to divert, am I obligated to choose between D and E, or can I divert to B, even though it is not in my atc flight plan? B is much more practical, and even though weather is generally the same at B and C, B has an ILS, so there is a good chance I would be able to land at B. Would I need to plan extra fuel for that? If I go with min fuel according to flight plan, choosing B would rule out at least one of the other alternates.
By the way, this is really only theoretical. Both airport B and C issue METARS, and we wouldn't really depart B unless we knew we could get into C.
As a secondary question. As airport C is so close to B. Would I actually require two alternates assuming METAR weather is good? I know there isn't technically a forecast, but as flight time is so close, could the METAR be considered the weather we will get on arrival?
Regarding the second question the answer is maybe (if you have a TREND), as You need to demonstrate that You have the applicable planning minima at ETA +/- 1 hour.
Anyway You can consider the no alternate option :
(1) the duration of the planned flight from take-off to landing or, in the event of in-flight replanning in accordance with CAT.OP.MPA.181(d), the remaining flying time to destination does not exceed 6 hours; and
(2) two separate runways are usable at the destination aerodrome, and the appropriate weather reports and/or forecasts for the destination aerodrome indicate that for the period from 1 hour before until 1 hour after the expected time of arrival at the destination aerodrome, the ceiling will be at least 2 000 ft (600 m) or the circling height +500 ft (150 m), whichever is greater, and the ground visibility will be at least 5 km.
Joined: Dec 2005
Aviation Qualifications: ATPL
Posts: 4,999
Likes: 341
From: Hong Kong
If you can't get into C, the obvious choice is to go back to B - you just came from there 10 minutes ago! I'd say that is more accurate weather info than any metar or taf.
de minimus non curat lex
Joined: Feb 2001
Posts: 1,510
Likes: 7
From: sunny troon
Many moons ago, I use to fly a Shorts 360. The morning route GLA-INV-KOI-LSI and return in the afternoon.
There were no TAFS issued that early for airports 2 & 3 although you had METARS. Close scrutiny of temperature & dew point was necessary to get a feeling in ones water.
So from a planning point of view 2 (academic) alternates were considered.
The bottom line in all these wee hops is always have a BOLT HOLE even if the facilities are less than ideal.
Don’t be brave, and take sufficient fuel to stop any anxiety ever building up.
There were no TAFS issued that early for airports 2 & 3 although you had METARS. Close scrutiny of temperature & dew point was necessary to get a feeling in ones water.
So from a planning point of view 2 (academic) alternates were considered.
The bottom line in all these wee hops is always have a BOLT HOLE even if the facilities are less than ideal.
Don’t be brave, and take sufficient fuel to stop any anxiety ever building up.
Last edited by parkfell; 6th October 2019 at 12:51.
Joined: Aug 2009
Posts: 10
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From: SPAIN
In-flight replanning
The planning and requirements for alternates are a dispatch requirement.
once you are airborne you can divert to any suitable airport, regardless of what your dispatch alternates were.
They're different phases of the flight process.
As for the second question, would you be comfortable standing in front of a judge and explaining your actions? Makes the decision fairly easy
once you are airborne you can divert to any suitable airport, regardless of what your dispatch alternates were.
They're different phases of the flight process.
As for the second question, would you be comfortable standing in front of a judge and explaining your actions? Makes the decision fairly easy
Please I need some help here.
So yesterday we were flying this ultra long flight ( +12h) and 4 hrs from destination we realize we are quite tight on fuel and destination TAF is horrendous in terms of visibility. As we prepare a plan B we notice the favourite alternate ( less distance ) has less than ideal conditions, as well visibility forecasted to be marginal. So different strategies are discussed and one of them is,...what if we proceed to this alternate , again, not very promising TEMPO wx conditions although METAR is still acceptable. My question here is, if we decide to fly to this planned alternate ( from dispatch) directly, at some point, without trying the original destination, is this considered inflight replannig therefore, all considerations for new alternates and planning minima apply? I think the answer is yes, but... it was the spark of a very vivid discuasion we had in the cockpit me and 2 other colleagues.
Thanks in advance
