Senario - do we need an alternate?
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Senario - do we need an alternate?
Here's a question for you....
This issue has come up repeatedly, and as far as I can tell, colleagues are evenly split on the answer.
Assume you are flying from A to B, with preflight WX not indicating alt required, so we are landing with standard company FOD (2.4 for 737 / 2.0 for Ejet).
ATC broadcasts a Hazard Alert for B, with WX now below the alt minima.
Do you now need an alternate for B ??
I have tried not to be leading in this senario - I have a strong opinion on the answer (which I'll withhold for now), and have sought answers from CAR, CAO, CAAP, Vol 1, Jepps etc, but opinions are divided.
Thoughts?
This issue has come up repeatedly, and as far as I can tell, colleagues are evenly split on the answer.
Assume you are flying from A to B, with preflight WX not indicating alt required, so we are landing with standard company FOD (2.4 for 737 / 2.0 for Ejet).
ATC broadcasts a Hazard Alert for B, with WX now below the alt minima.
Do you now need an alternate for B ??
I have tried not to be leading in this senario - I have a strong opinion on the answer (which I'll withhold for now), and have sought answers from CAR, CAO, CAAP, Vol 1, Jepps etc, but opinions are divided.
Thoughts?
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If 'B' has TTF forecasting, I'd be checking that, and if it indicates a change to conditions below the alternate minima, then, yes, you do need an alternate. If you don't have the fuel to go anywhere, then I guess it's a PAN call and some paperwork afterwards.
What sort of hazardous WX are you talking about?
If 'B' is only covered by the original forecast, but the actual is as you describe, then a decision is required based on other airport availability and remaining fuel.
Again, it comes down to where else could you go.
What sort of hazardous WX are you talking about?
If 'B' is only covered by the original forecast, but the actual is as you describe, then a decision is required based on other airport availability and remaining fuel.
Again, it comes down to where else could you go.
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Great question, a very grey area indeed, I will look forward to viewing the answers! 
In short my opinion is that you do need an alternate if the forecast/TTF goes below minimums while enroute! Now I will need to go and find a reference to support that choice.
In short my opinion is that you do need an alternate if the forecast/TTF goes below minimums while enroute! Now I will need to go and find a reference to support that choice.
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My 2cents
Once your airborne all bets are off, as long as the weather at destination stays above the landing minima no probs.
Its a bit hard to add extra fuel to satisfy an alternate requirement once your airborne.
Once your airborne all bets are off, as long as the weather at destination stays above the landing minima no probs.
Its a bit hard to add extra fuel to satisfy an alternate requirement once your airborne.
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I'm with Whe Cares on this one. My understanding is that the legal concept of an "Alternate" is applied during the flight planning stage only. Once you have dispatched/pushed back/airborne or whatever you gotta call it, the weather at your destination needs to be above landing minima only, in order for you to conduct an approach. I am not commenting on the airmanship/sensibility of operating towards a destination if landing is not assured, but merely whether you actually legally "need" to carry an alternate if the the destination forecast has changed.
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ATC broadcasts a Hazard Alert for B, with WX now below the alt minima.
A range of options is now possible depending on the exact nature of the weather and my fuel state. Care to provide a little more information?
Hazard alert is issued for a change that has an immediate and detrimental effect on the subject. I don't think it per se constitutes a new forecast so an alt is not legally required. But it does imply a new forecast is coming. Once a new forecast is acquired then you must have the fuel. You could stick your head in the sand and not obtain the updated forecast and so continue. (Not what I would recommend)
In the above scenario I would think that AIRMANSHIP would dictate that alt fuel/holding fuel should be held, unless you have no fuel to go elsewhere i.e you are past the point of last diversion.
What about if it was severe low level windshear, or X-wind exceeding the limits etc. etc. what would be most prudent?
In the above scenario I would think that AIRMANSHIP would dictate that alt fuel/holding fuel should be held, unless you have no fuel to go elsewhere i.e you are past the point of last diversion.
What about if it was severe low level windshear, or X-wind exceeding the limits etc. etc. what would be most prudent?
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Hazard alert is issued for a change that has an immediate and detrimental effect on the subject. I don't think it per se constitutes a new forecast so an alt is not legally required. But it does imply a new forecast is coming. Once a new forecast is acquired then you must have the fuel.You could stick your head in the sand and not obtain the updated forecast and so continue. (Not what I would recommend)
Yeah Right!
If that was the case, why do we end up with aircraft parked all over the east coast when SYD weather goes down unexpectedly!
Once you have dispatched/pushed back/airborne or whatever you gotta call it, the weather at your destination needs to be above landing minima only
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My $.03 (thinking as I type ...)
AIP lists three key areas to be considered when deciding whether an alternate is required: Weather, Lighting, & Navaids. When an alternate is required for weather or lighting, carrying sufficient holding fuel is an option, but for most of us it isn't practical to take on fuel in flight.
Since you can't take on additional fuel in flight, whether for holding or diverting to an alternate, once a flight has commenced you only have whatever is the tanks. So any calculation of fuel for alternates must be done at the flight planning stage. Unless you take vast amounts of unrequired fuel, there's no practical way to (re-)plan your alternate(s) in flight in most parts of Australia.
BTW WRT "the weather at your destination needs to be above landing minima only, in order for you to conduct an approach" in Australia, there's nothing in the rules to stop you starting an approach even if the weather is below that specified for the approach. i.e. There's no prohibition on "taking a look". What you can't do, of course, is continue past the DA/MDA if the weather is below the minima.
AIP lists three key areas to be considered when deciding whether an alternate is required: Weather, Lighting, & Navaids. When an alternate is required for weather or lighting, carrying sufficient holding fuel is an option, but for most of us it isn't practical to take on fuel in flight.
Since you can't take on additional fuel in flight, whether for holding or diverting to an alternate, once a flight has commenced you only have whatever is the tanks. So any calculation of fuel for alternates must be done at the flight planning stage. Unless you take vast amounts of unrequired fuel, there's no practical way to (re-)plan your alternate(s) in flight in most parts of Australia.
BTW WRT "the weather at your destination needs to be above landing minima only, in order for you to conduct an approach" in Australia, there's nothing in the rules to stop you starting an approach even if the weather is below that specified for the approach. i.e. There's no prohibition on "taking a look". What you can't do, of course, is continue past the DA/MDA if the weather is below the minima.
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Absolutely...you need an alternate. If you do not have the required fuel then a diversion is required. If a diversion cannot be achieved then it's a PAN call. At the end of the day this is all about situational awareness and what is available inflight.
For example: MEL to PER, no requirements preflight. At TOPD tempo TS are issued for PER. Since the FOB is not sufficient to hold the tempo and the PNR for KG is probably around the 20000' mark on descent, it's a 180 and divert to KG. If however, KG was not available (say due to WIP) then you are well past your PNR for AD and in this case you are committed to a landing at PER. In the first example, you would be hard pressed to try and explain to CASA that you didn't have to divert to KG because preflight all was ok.
For example: MEL to PER, no requirements preflight. At TOPD tempo TS are issued for PER. Since the FOB is not sufficient to hold the tempo and the PNR for KG is probably around the 20000' mark on descent, it's a 180 and divert to KG. If however, KG was not available (say due to WIP) then you are well past your PNR for AD and in this case you are committed to a landing at PER. In the first example, you would be hard pressed to try and explain to CASA that you didn't have to divert to KG because preflight all was ok.
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The question presupposes that you are in a position to consider diversion. The Hazard Alert with WX now below the alt minima may come so late in the flight that you have no options available other than to continue to destination as planned - example 320 autoland at Adelaide in un-forecast fog some time ago.
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Some years ago i remember a 747 freighter inbound to Syd, there was forcast fog which did eventuate. So they started their diversion to Mel to be told 15min later that it was closed due to fog.
Do you think he had the fuel to for another alternate.
Nope.. he returned to Syd with an autoland.
Do you think he had the fuel to for another alternate.
Nope.. he returned to Syd with an autoland.
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who_cares wrote
Please tell us that you are the sole occupant of a VH registered aircraft.
Once your airborne all bets are off, as long as the weather at destination stays above the landing minima no probs.
When you live....
I'm in the camp with those who believe Alternates in the ALTN sense are flight planning beasts only. As soon as I'm airborne then I'm required to manage the flight considering all the conditions around me.
Unplanned deteriorations at either the destination or planned alternate require attention and decision making - this is not only airmanship but, if not legally mandated, would at the very least open one up to a charge of negilgence or reckless endangerment should things go pear shaped.
So technically - in the example given - no, an new alternate is not required in the flight planning/notification sense (otherwise you'd be hearing flight plan amendment requests all over the radio as people changed their ALTN). Practically, everyone here agrees that in the above scenario some rapid in-flight replanning would be done and a new plan developed which would cover ones arse in the event of an unfortunate outcome.
For those who believe that an ALTN is required mid-flight, riddle me this - what if there isn't one? You can't just press CTL-ALT-DEL and start again - and no one could go you for not having one......
UTR
PS There was a thread ages ago about starting approaches with less than DH/MDA conditions. IIRC, in Oz it's ok to have a look anyway, in the US it isn't.
Unplanned deteriorations at either the destination or planned alternate require attention and decision making - this is not only airmanship but, if not legally mandated, would at the very least open one up to a charge of negilgence or reckless endangerment should things go pear shaped.
So technically - in the example given - no, an new alternate is not required in the flight planning/notification sense (otherwise you'd be hearing flight plan amendment requests all over the radio as people changed their ALTN). Practically, everyone here agrees that in the above scenario some rapid in-flight replanning would be done and a new plan developed which would cover ones arse in the event of an unfortunate outcome.
For those who believe that an ALTN is required mid-flight, riddle me this - what if there isn't one? You can't just press CTL-ALT-DEL and start again - and no one could go you for not having one......
UTR
PS There was a thread ages ago about starting approaches with less than DH/MDA conditions. IIRC, in Oz it's ok to have a look anyway, in the US it isn't.
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riddle me this - what if there isn't one?
That ASIR may now be the subject of investigation by CASA.
See the ATSB A330 report on the PER incident.
from the report
Perth and Learmonth were the only aerodromes in Western Australia that could be classified as suitable for the A330, and Learmonth was 599 NM (1,110 km) from Perth.
As a result of this occurrence, the operator implemented an interim flight planning fuel policy specifically for Perth.
As a result of this occurrence, the operator implemented an interim flight planning fuel policy specifically for Perth.
Breakfastburrito,
There is a big difference berween landing less than alternate minima and landing less than landing minima. I would definitely declare a pan for the latter but only declare a pan for the former if the conditions warranted.
There is a big difference berween landing less than alternate minima and landing less than landing minima. I would definitely declare a pan for the latter but only declare a pan for the former if the conditions warranted.
Last edited by desmotronic; 29th Jan 2009 at 05:26. Reason: transposed pronouns
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desmotronic, quite true from a practical point of view. However the legalities don't change. If, in the QF A330 PER case the WX, had hypothetically been below the ALT criteria, but above the landing minima I believe the crew would still have been required to make a PAN and submit an ASIR to be legal.
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At no point have I advocated that you would continue merrily on your way to your destination without considering other alternatives.
But sometimes there maybe be now other course of action. you cant put fuel in your tanks when airborne or move suitable aerodromes closer.
But sometimes there maybe be now other course of action. you cant put fuel in your tanks when airborne or move suitable aerodromes closer.
Hi breakfastburrito,
I don't see the need to declare a PAN if the destination weather is above landing minima. That's a bit of overkill.
I'm afraid i can't add much from the Australian perspective, but fwiw, in my company we differentiate between flight planning and in flight considerations. This may include nominating a new destination and/or alternate in the air, but the primary motivation is a safe conclusion of the flight based on actual conditions.
The academic nature of this discussion is probably appropriate on the ground but not in the air. As in the Qantas A330 incident, if the **** really hits the fan and the weather craps out, you just do whatever you can.
Cheers.
edit: typo
I don't see the need to declare a PAN if the destination weather is above landing minima. That's a bit of overkill.
I'm afraid i can't add much from the Australian perspective, but fwiw, in my company we differentiate between flight planning and in flight considerations. This may include nominating a new destination and/or alternate in the air, but the primary motivation is a safe conclusion of the flight based on actual conditions.
The academic nature of this discussion is probably appropriate on the ground but not in the air. As in the Qantas A330 incident, if the **** really hits the fan and the weather craps out, you just do whatever you can.
Cheers.
edit: typo