VCTS: Alternate Requirement?
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VCTS: Alternate Requirement?
Hi all,
Have searched Google and on here for any discussion about this, so be gentle.
Sydney's TTF on Sunday was intermittently endorsed with VCTS. I was pretty certain that doesn't call for any alternate/holding fuel, and was checking the AIP to confirm definitions (TAF forecasts valid for within 5nm of ARP, VC is approx 8-16km ARP (8km = 4.3nm...good one
) and the TS alternate requirement is if the storms/associated severe turb are forecast at the destination). Is the consensus that it doesn't impose any requirements?
Was thinking of asking CASA but thought I'd get a quicker response here
Have searched Google and on here for any discussion about this, so be gentle.
Sydney's TTF on Sunday was intermittently endorsed with VCTS. I was pretty certain that doesn't call for any alternate/holding fuel, and was checking the AIP to confirm definitions (TAF forecasts valid for within 5nm of ARP, VC is approx 8-16km ARP (8km = 4.3nm...good one
) and the TS alternate requirement is if the storms/associated severe turb are forecast at the destination). Is the consensus that it doesn't impose any requirements?Was thinking of asking CASA but thought I'd get a quicker response here
Oooorrrr maybe it's a last minute addition just prior to your arrival and you'd get in no probs if only continuing was legal
CASA wouldn't give a definitive answer anyway. They would just say that it would depend on the circumstances. Those circumstances being if you had an incident that involved a TS being in the vicinity of the airport. In my interpretation I would say you don't have to carry the fuel but you would be crazy not to.
Yes.
A forecast of storms or their probability requires an alternate unless it’s endorsed with tempo or inter.
Let’s also think of it practically. There’s a big cell at 8nm on the centreline of the most into wind runway. It’s affecting arrivals. The sequence slows. You’re held until they can slot you in.
The only time you’d disregard this is on an ETOPS flight. As long as the wx conditions are above landing minima, you’re good.
A forecast of storms or their probability requires an alternate unless it’s endorsed with tempo or inter.
Let’s also think of it practically. There’s a big cell at 8nm on the centreline of the most into wind runway. It’s affecting arrivals. The sequence slows. You’re held until they can slot you in.
The only time you’d disregard this is on an ETOPS flight. As long as the wx conditions are above landing minima, you’re good.
Yes.
A forecast of storms or their probability requires an alternate unless it’s endorsed with tempo or inter.
Let’s also think of it practically. There’s a big cell at 8nm on the centreline of the most into wind runway. It’s affecting arrivals. The sequence slows. You’re held until they can slot you in.
The only time you’d disregard this is on an ETOPS flight. As long as the wx conditions are above landing minima, you’re good.
A forecast of storms or their probability requires an alternate unless it’s endorsed with tempo or inter.
Let’s also think of it practically. There’s a big cell at 8nm on the centreline of the most into wind runway. It’s affecting arrivals. The sequence slows. You’re held until they can slot you in.
The only time you’d disregard this is on an ETOPS flight. As long as the wx conditions are above landing minima, you’re good.
Last edited by t_cas; 26th Oct 2017 at 21:12.
A unique Australian requirement
I've gotta say the term Austronaut is a good one.
A unique Australian requirement
The bit that says you need extra fuel when thunderstorms are forecast. Pretty sure under ICAO there's no such requirement. Certainly all the pilots I've flown with overseas have never heard of it except for the Australians.
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The original question was a very good one.
Can I please ask for clarification from m.r.a.z.23; you said it was a TTF and that it had intermittent endorsement of VCTS.
As the TTF is made up of two elements; the METAR and the trend, was the VCTS on the METAR part or the trend part?
I have never seen a forecast of VCTS, but I have seen many observations (METARs) of VCTS.
I doubt that a forecast would have that in it because it's too non-specific.
Can I please ask for clarification from m.r.a.z.23; you said it was a TTF and that it had intermittent endorsement of VCTS.
As the TTF is made up of two elements; the METAR and the trend, was the VCTS on the METAR part or the trend part?
I have never seen a forecast of VCTS, but I have seen many observations (METARs) of VCTS.
I doubt that a forecast would have that in it because it's too non-specific.
Captn Fathom, in the new forecasts, TS will be listed, or not. The “prob 30%” will disappear.
Also, forecasts won’t be updated if the weather improves...
Such a brave new world for Austronauts (Great term!)
It is interesting at a recent Avsafety seminar to hear CASA say that BoM are insisting on the changes to bring Oz in line with ICAO, but at another seminar, BoM were saying nothing to do with them, it’s a CASA requirement!
Also, forecasts won’t be updated if the weather improves...
Such a brave new world for Austronauts (Great term!)
It is interesting at a recent Avsafety seminar to hear CASA say that BoM are insisting on the changes to bring Oz in line with ICAO, but at another seminar, BoM were saying nothing to do with them, it’s a CASA requirement!
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m.r.a.z.23,
I would take it that the VCTS does impose the operational requirements. There is nothing in the rules about distances. You seem to be somewhat hung up regarding distances but I suggest they are a red herring.
The rules simply state "TS at the destination". Does "VC" constitute "at"? My reading would be yes, on the grounds that any weather mentioned in METAR, TTF and TAF would be intended to be considered "at", as that is the whole purpose of those reports/forecasts.
I would take it that the VCTS does impose the operational requirements. There is nothing in the rules about distances. You seem to be somewhat hung up regarding distances but I suggest they are a red herring.
The rules simply state "TS at the destination". Does "VC" constitute "at"? My reading would be yes, on the grounds that any weather mentioned in METAR, TTF and TAF would be intended to be considered "at", as that is the whole purpose of those reports/forecasts.
on the grounds that any weather mentioned in METAR, TTF and TAF would be intended to be considered "at", as that is the whole purpose of those reports/forecasts.
What about RETS? Are you also required to carry fuel for that? I would be interested to see the TTF that the OP was looking at.
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m.r.a.z.23,
On reflection, I now think the opposite of what I did yesterday.
The rules state that TS impose an operational requirement when FORECAST at the destination.
But when you see VCTS, you are not looking at a forecast but are looking at either a METAR or the "report" component of the TTF.
You will never see VCTS in a forecast. Therefore, VCTS cannot trigger the operational requirement. This can only happen via a TAF or ARFOR.
On reflection, I now think the opposite of what I did yesterday.
The rules state that TS impose an operational requirement when FORECAST at the destination.
But when you see VCTS, you are not looking at a forecast but are looking at either a METAR or the "report" component of the TTF.
You will never see VCTS in a forecast. Therefore, VCTS cannot trigger the operational requirement. This can only happen via a TAF or ARFOR.