IFR Alternate Question
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IFR Alternate Question
Hello fellow aviation enthusiasts, I have a question: Does this aerodrome require an Alternate? (for an IFR flight to the aerodrome in DAY VMC)
IFR Aerodrome, (R-NAV) available.
No TAF serivice available.
No Navaid at Aerodrome.
I`m 99% sure it it does require an alternate as the Jepps say something like "If aerodrome forecast is provisional/Not available" alternate must be planned with a firm forecast".
To me it seems rather clear, however, Some have suggested that you can plan without an alternate using the "500` Above LSALT / 8km at Aerodrome rule" and just use the Area Forecast, but that is under the RADIO AIDS section of the Jepps and refers to flight to an aerodrome not having a radio aid on the ground, and has nothing to do with a TAF being available or not.
Anyone got a definitive answer? if so could you let me know the Jepp reference.
cheers,
M.L.
IFR Aerodrome, (R-NAV) available.
No TAF serivice available.
No Navaid at Aerodrome.
I`m 99% sure it it does require an alternate as the Jepps say something like "If aerodrome forecast is provisional/Not available" alternate must be planned with a firm forecast".
To me it seems rather clear, however, Some have suggested that you can plan without an alternate using the "500` Above LSALT / 8km at Aerodrome rule" and just use the Area Forecast, but that is under the RADIO AIDS section of the Jepps and refers to flight to an aerodrome not having a radio aid on the ground, and has nothing to do with a TAF being available or not.
Anyone got a definitive answer? if so could you let me know the Jepp reference.
cheers,
M.L.
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Jepp ATC page AU-303
3.1.3
No TAF available, so you have to plan for an alternate that does have a firm forecast.
Further, re the navaids AU-304
because no TAF available, 3.3.2 a) is not available to you and therefore alternate again required. The wording is vague but does require vis and cloud forecast at the destination aeordrome which to me an area forecast would not cut it.
i.e. If a TAF was available, no alternate is required by day if you can get relief under 3.3.2 a)
Thats my answer anyway. I'm sure someone will be along shortly with something different.
3.1.3
No TAF available, so you have to plan for an alternate that does have a firm forecast.
Further, re the navaids AU-304
because no TAF available, 3.3.2 a) is not available to you and therefore alternate again required. The wording is vague but does require vis and cloud forecast at the destination aeordrome which to me an area forecast would not cut it.
i.e. If a TAF was available, no alternate is required by day if you can get relief under 3.3.2 a)
Thats my answer anyway. I'm sure someone will be along shortly with something different.
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Can't help with a Jepp ref, but.............
AIP ENR 1.1 57.1.3
When an aerodrome forecast is not available or provisional, the PIC must make provision for a suitable alternate that has a firm forecast.
AIP ENR 1.1 57.2.9
For IFR Flights, the alternate minima are as follows:
a) For aerodromes with an instrument approach procedure, the alternate minima published on the chart.
b) For aerodromes with an instrument approach procedure where an aerodrome forecast is unavailable or provisional, the PIC must make provision for a suitable alternate.
c) For aerodromes without an instrument approach procedure, the alternate minima is the lowest safe altitude for the final route segment plus 500ft and a visibility of 8km.
Now, what we have here is interpretation issues- just like the cirlcing minima but let's not start that up again!
Key words in the first bit of bolding - "AERODROME FORECAST".
The 2nd bolding says that even if you have an approach, but no aerodrome forecast, you need an alternate.
The 3rd bolding gives provision for IFR flight to a no-aid aerodrome but which does have a forecast- the interpretation problem arises because they do not state WHERE the cloud and vis info must come from.
AIP ENR 1.1 57.1.3
When an aerodrome forecast is not available or provisional, the PIC must make provision for a suitable alternate that has a firm forecast.
AIP ENR 1.1 57.2.9
For IFR Flights, the alternate minima are as follows:
a) For aerodromes with an instrument approach procedure, the alternate minima published on the chart.
b) For aerodromes with an instrument approach procedure where an aerodrome forecast is unavailable or provisional, the PIC must make provision for a suitable alternate.
c) For aerodromes without an instrument approach procedure, the alternate minima is the lowest safe altitude for the final route segment plus 500ft and a visibility of 8km.
Now, what we have here is interpretation issues- just like the cirlcing minima but let's not start that up again!
Key words in the first bit of bolding - "AERODROME FORECAST".
The 2nd bolding says that even if you have an approach, but no aerodrome forecast, you need an alternate.
The 3rd bolding gives provision for IFR flight to a no-aid aerodrome but which does have a forecast- the interpretation problem arises because they do not state WHERE the cloud and vis info must come from.
Last edited by MyNameIsIs; 18th Jun 2011 at 04:31.
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RNAV is your only approach available. If you have a 129 GPS then alt required. If you have a 146a GPS no alt required due aids.
If the area forecast indicates your last route segment can be flown under the rule no more than sct cloud below 500ft above LSALT & vis > 8k then no alt required. The difficulty is deciding from the area forecast wether this is the case at your particular destination given the sometimes vague nature of these forecasts regarding areas within the forecast and you don't know the crosswind component for your planned runway either. So my usual move is to plan for an alt anyway if there is no TAF.
If the area forecast indicates your last route segment can be flown under the rule no more than sct cloud below 500ft above LSALT & vis > 8k then no alt required. The difficulty is deciding from the area forecast wether this is the case at your particular destination given the sometimes vague nature of these forecasts regarding areas within the forecast and you don't know the crosswind component for your planned runway either. So my usual move is to plan for an alt anyway if there is no TAF.
The existance of a TSO 145a/146a GPS doesn't automatically guarantee no alt due navaids. Must also be listed in POH supps as being installed to that standard and you must have a current database and a valid FDE prediction of RAIM availability at that location.
I must admit, I'm a tad confused, Its pretty black and white to me.
AIP ENR 1.1 57.1.3
When an aerodrome forecast is not available or provisional, the PIC must make provision for a suitable alternate that has a firm forecast.
Its irrelevant if you have the ability to do an instrument approach or not. Its irrelevant if you think you can somehow ascertain the conditions for 1 airport off an area forecast or not.
Furthermore its not permissible to use RNAV alone to remove an alternate requirement when considering instrument approach options. See ENR 1.1 58.3 That said I stand to be corrected on that one as its been a while since ive read the regs re RNAV.
If you don't have an aerodrome forecast, you require an alternate. Show me where it states otherwise.
AIP ENR 1.1 57.1.3
When an aerodrome forecast is not available or provisional, the PIC must make provision for a suitable alternate that has a firm forecast.
Its irrelevant if you have the ability to do an instrument approach or not. Its irrelevant if you think you can somehow ascertain the conditions for 1 airport off an area forecast or not.
Furthermore its not permissible to use RNAV alone to remove an alternate requirement when considering instrument approach options. See ENR 1.1 58.3 That said I stand to be corrected on that one as its been a while since ive read the regs re RNAV.
If you don't have an aerodrome forecast, you require an alternate. Show me where it states otherwise.
I think Superior Soldier is right again about this. I can't see anything more bald than what's written in the AIP's regardless of what super duper GPS you have.
Rules are rules!
Rules are rules!
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das Uber Soldat, under your reasoning you can you fly to an aerodrome without a TAF under VFR without an alternate on a CAVOK day, but going IFR requires an alternate...
In my books, use the area forecast to judge whether it is 8km vis and a ceiling 500ft above the last route segments' LSALT. (AIP ENR 1.1 57.2.9 / AU304 3.2.12c)
AU601 1.2.1
A forecast must be either a flight forecast or an area forecast with an aerodrome forecast for the destination and, when required, the alternate aerodrome. For a flight to a destination for which a prescribed instrument procedure does not exist, the minimum requirement is an Area Forecast.
AU601 1.4.1
A flight operating under IFR by day may be planned to a non-instrument procedure destination provided that the aircraft can be navigated in accordance with General Flight Procedures. When the forecast for the destination is below the alternate minima (i) specified in Airports and Ground Aids, the pilot-in-command must ensure that a suitable alternate has been nominated.
(i)
AU304 3.2.12c
For aerodromes without an instrument approach procedure, the alternate minima are the lowest safe altitude for the final route segment plus 500ft and a visibility of 8km
In my books, use the area forecast to judge whether it is 8km vis and a ceiling 500ft above the last route segments' LSALT. (AIP ENR 1.1 57.2.9 / AU304 3.2.12c)
AU601 1.2.1
A forecast must be either a flight forecast or an area forecast with an aerodrome forecast for the destination and, when required, the alternate aerodrome. For a flight to a destination for which a prescribed instrument procedure does not exist, the minimum requirement is an Area Forecast.
AU601 1.4.1
A flight operating under IFR by day may be planned to a non-instrument procedure destination provided that the aircraft can be navigated in accordance with General Flight Procedures. When the forecast for the destination is below the alternate minima (i) specified in Airports and Ground Aids, the pilot-in-command must ensure that a suitable alternate has been nominated.
(i)
AU304 3.2.12c
For aerodromes without an instrument approach procedure, the alternate minima are the lowest safe altitude for the final route segment plus 500ft and a visibility of 8km
Last edited by tmpffisch; 18th Jun 2011 at 08:18. Reason: added regs
Even think about it logically for a second - I got the most bestest GPS in the world, I'm current, the RAIM & FDE are good - and it's foggy ...
That's why an alternate is always required if you don't have an AD forecast.
It's not rocket science, and even better, the rules says so!
That's why an alternate is always required if you don't have an AD forecast.
It's not rocket science, and even better, the rules says so!
das Uber Soldat, under your reasoning you can you fly to an aerodrome without a TAF under VFR without an alternate on a CAVOK day, but going IFR requires an alternate...
I've often joked with colleagues about the contradictory nature of the regs and this is no exception. There is more than 1 example I can find where a VFR aircraft gets away without requiring an alternate when an IFR aircraft would!
It might be stupid, but when you have idiots running the show stupidity is generally what they produce
AU601 1.2.1
A forecast must be either a flight forecast or an area forecast with an aerodrome forecast for the destination and, when required, the alternate aerodrome. For a flight to a destination for which a prescribed instrument procedure does not exist, the minimum requirement is an Area Forecast.
And it makes no mention of requiring an alternate. You still would require an alternate
AU601 1.4.1
A flight operating under IFR by day may be planned to a non-instrument procedure destination provided that the aircraft can be navigated in accordance with General Flight Procedures. When the forecast for the destination is below the alternate minima (i) specified in Airports and Ground Aids, the pilot-in-command must ensure that a suitable alternate has been nominated.
(i)
AU304 3.2.12c
For aerodromes without an instrument approach procedure, the alternate minima are the lowest safe altitude for the final route segment plus 500ft and a visibility of 8km
None of which you can reliably ascertain from an area forecast
All you've shown me are a few isolated paragraphs that through hazy inference suggest you can get away without an aerodrome forecast. Nothing that properly contradicts the black and white statement, listed at the very start of the Alternate requirements section of the AIP in no uncertain terms;
AIP ENR 1.1 57.1.3
When an aerodrome forecast is not available or provisional, the PIC must make provision for a suitable alternate that has a firm forecast.
There is no 57.1.3b "Unless you're pretty sure you can get specific enough information out of a area forecast.. after all, bathurst is near the ranges right?!"
In my books on an average weather day, you'd be a brave soul to fly without a TAF to an airport and plan to arrive there with min reserves because you picked the cloud base from the "CLD" section of the ARFOR and the vis from the vis description of a area a few thousand square KM.
A forecast must be either a flight forecast or an area forecast with an aerodrome forecast for the destination and, when required, the alternate aerodrome. For a flight to a destination for which a prescribed instrument procedure does not exist, the minimum requirement is an Area Forecast.
And it makes no mention of requiring an alternate. You still would require an alternate
AU601 1.4.1
A flight operating under IFR by day may be planned to a non-instrument procedure destination provided that the aircraft can be navigated in accordance with General Flight Procedures. When the forecast for the destination is below the alternate minima (i) specified in Airports and Ground Aids, the pilot-in-command must ensure that a suitable alternate has been nominated.
(i)
AU304 3.2.12c
For aerodromes without an instrument approach procedure, the alternate minima are the lowest safe altitude for the final route segment plus 500ft and a visibility of 8km
None of which you can reliably ascertain from an area forecast
All you've shown me are a few isolated paragraphs that through hazy inference suggest you can get away without an aerodrome forecast. Nothing that properly contradicts the black and white statement, listed at the very start of the Alternate requirements section of the AIP in no uncertain terms;
AIP ENR 1.1 57.1.3
When an aerodrome forecast is not available or provisional, the PIC must make provision for a suitable alternate that has a firm forecast.
There is no 57.1.3b "Unless you're pretty sure you can get specific enough information out of a area forecast.. after all, bathurst is near the ranges right?!"
In my books on an average weather day, you'd be a brave soul to fly without a TAF to an airport and plan to arrive there with min reserves because you picked the cloud base from the "CLD" section of the ARFOR and the vis from the vis description of a area a few thousand square KM.
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GentsThere were 2 parts to the OPs question.
As I read it, he asks for an answer to both parts in isolation. I think we all know and agree a 146a gps does not give free licence to do what you want.
As I read it, he asks for an answer to both parts in isolation. I think we all know and agree a 146a gps does not give free licence to do what you want.
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dUS
Reading your posts, we agree. No TAF = Alt reqd.
Regarding the RNAV bit, and a seperate argument now
Jepp RADIO AIDS page AU-8 refers
Unless using a 145a or 146a receiver with a valid FDE prediction, at both the dest and altn if reqd, provision for an altn may not be based on RNAV(GNSS) appr capability.
Agree, clear as mud.
Reading your posts, we agree. No TAF = Alt reqd.
Regarding the RNAV bit, and a seperate argument now
Jepp RADIO AIDS page AU-8 refers
Unless using a 145a or 146a receiver with a valid FDE prediction, at both the dest and altn if reqd, provision for an altn may not be based on RNAV(GNSS) appr capability.
Agree, clear as mud.
ah ok. I called a mate who informed me that the RNAV rules changed a while ago and can now under certain circumstances be counted as a radio aid when assessing the requirement for an alternate.
Having never flown one in my life I wasn't up to date on the regs. There you go, learn something every day
Cheers
Having never flown one in my life I wasn't up to date on the regs. There you go, learn something every day
Cheers
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MajorLemond,
You do NOT require an alternate for the IFR scenario you described.
About 90% of the people you ask this question of, however, will say that you do, because they are reading the following rule too literally:
The words "not available" in that rule do not mean what the 90% think they do.
That rule is actually referring to cases where an aerodrome forecast is USUALLY available (i.e those places with navaids that have TAF coverage for the daytime only). During night hours, there will be no TAF - so this rule then applies.
This rule does NOT apply to aerodromes that never have TAFs issued for them.
I could go into why the rules are like this but I might save that for a future post.
For those that think an IFR flight DOES require an alternate in this scenario but a VFR flight does NOT, have another look at that rule (above). You will see that it does not distinguish between IFR and VFR.
So, according to the 90%, VFR flights can't go very far, because they always must be carrying alternate fuel to an aerodrome that has a TAF!
The 90% are wrong, of course, because the interpretation of that rule is the same for VFR as it is for IFR - and it means that, just like for IFR, the VFR flight does NOT need an alternate in the scenario given.
Correct! This rule would not exist if the interpretation of the 90% was correct.
You do NOT require an alternate for the IFR scenario you described.
About 90% of the people you ask this question of, however, will say that you do, because they are reading the following rule too literally:
AIP ENR 1.1 57.1.3
When an aerodrome forecast is not available or provisional, the PIC must make provision for a suitable alternate that has a firm forecast.
When an aerodrome forecast is not available or provisional, the PIC must make provision for a suitable alternate that has a firm forecast.
That rule is actually referring to cases where an aerodrome forecast is USUALLY available (i.e those places with navaids that have TAF coverage for the daytime only). During night hours, there will be no TAF - so this rule then applies.
This rule does NOT apply to aerodromes that never have TAFs issued for them.
I could go into why the rules are like this but I might save that for a future post.
For those that think an IFR flight DOES require an alternate in this scenario but a VFR flight does NOT, have another look at that rule (above). You will see that it does not distinguish between IFR and VFR.
So, according to the 90%, VFR flights can't go very far, because they always must be carrying alternate fuel to an aerodrome that has a TAF!
The 90% are wrong, of course, because the interpretation of that rule is the same for VFR as it is for IFR - and it means that, just like for IFR, the VFR flight does NOT need an alternate in the scenario given.
Some have suggested that you can plan without an alternate using the "500` Above LSALT / 8km at Aerodrome rule" and just use the Area Forecast
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Hi fdg135,
I have heard a similar argument, have you got reference? Not trying to be a smartass or anything but I need to see a reg which states that for my own peace of mind... considering your reasoning is legitiment, and if an area forecast is suitable to determine the wx at an aerodrome which never has a taf... then why can't it be used for an aerodrome that " usually has a taf produced but is not available "
It makes zero sense to me if this is the case.
I have heard a similar argument, have you got reference? Not trying to be a smartass or anything but I need to see a reg which states that for my own peace of mind... considering your reasoning is legitiment, and if an area forecast is suitable to determine the wx at an aerodrome which never has a taf... then why can't it be used for an aerodrome that " usually has a taf produced but is not available "
It makes zero sense to me if this is the case.
