IFR Alternate Question
This thread had run it's course. In debating hard for a definitive answer, the only one we have discovered is that there isn't one.
Valid points can be made for both sides of the argument and clearly there is no final answer on the topic.
Common sense will be ruling my fuel plan decisions and I thank my lucky stars I don't have to operate into ports without tafs!
Continue the hamster wheel at your own peril
Valid points can be made for both sides of the argument and clearly there is no final answer on the topic.
Common sense will be ruling my fuel plan decisions and I thank my lucky stars I don't have to operate into ports without tafs!
Continue the hamster wheel at your own peril
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2. Your assertion applies equally to VFR flight - and is utterly non-sensical when so applied. According to you, the VFR cockie needs to find out if his destination has an IAP. If it does (but has no TAF), he must then carry alternate fuel to an aerodrome that doesn't (or has a TAF)!
One final story. Some might say it is an airmanship decision but you can decide in which pilot's shoes you would rather be in for this very possible real world scenario:
PILOT A: Boss says "Take as much cargo as you possibly can." You have multiple trips to do anyway so the more you take the better and the boss has left drum fuel supply at the destination, Jameson Ranges. You start before dawn pulling the plane out of the hangar at Kalgoorlie. You read the forecast which shows that the trough is still hanging around the central interior. ARFOR indicates more cloud in the Southern region of Area 64. In the remaining area, which includes your destination to the North, the only cloud to worry about appears to be a low layer of SCT which is below the LSALT (but it is not MORE than SCT). The next layer is BKN about 1000ft above your LSALT. Worst vis that is mentioned for the North is reducing to 8km in light showers. You decide to go with a minimum fuel load and refuel out of the drums at Jameson.
A while later you find yourself in the early morning light approaching Jameson at the LSALT. You are now sitting between layers but it looks like that low layer has turned into a solid overcast at probably no more than 500ft AGL and that the worse weather predicted for the South of the region has actually spread further North than expected and with the early morning sun the cloud has thickened - especially after that rain overnight. The TAF for Warburton further to the West wasn't too bad but they have just announced an ammended TAF for SCT at 600ft and BKN at 4,000ft. There is rain coming out of the layer above you and as you contemplate having to try and get through that lower layer to a boggy, wet strip with your fuel guages starting to knock on reserves you suddenly feel very cold and alone wondering how you got yourself into this situation...
PILOT B: He read the same forecast and is about to do the same job as PILOT A. He decided to carry enough extra fuel to get across to Warburton. Arriving over Jameson with the same real world weather as PILOT A he says "stuff this!" and sets course for Warburton. Even though the ammended TAF is SCT at 600ft you know you will still get in there. You even have an NDB approach or RNAV approach to help you! It is a sealed strip to boot. You look forward to putting your feet up on solid ground until you can try again later in the day when the weather lifts. You also decide it might be wise to get a strip report for Jameson too incase the extra rain overnight has deemed it too wet for use.
I know who's shoes I would rather be in even though some could argue that both pilots set off on a legal flight.
Okay, I really do plan on getting off the hamster wheel now!
Last edited by Captain Nomad; 22nd Jun 2011 at 03:26.
with the same real world weather as PILOT A he says "stuff this!" and sets course for Warburton. Even though the ammended TAF is SCT at 600ft you know you will still get in there.
What's your point?
It's possible for the forecast to be wrong? 
When the weather is AS FORECAST, pilot A gets the job done in two trips, and pilot B (loaded up with gas) takes three - the difference between a profit and a loss on the job. When the company goes under, pilot B can feel righteous standing next to poor pilot A in the dole queue...
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In reference to the Bob Tait Instrument Rating Study Guide,
Question 31
You are planning an IFR charter flight in VH-OZY into an aerodrome for which no TAF is available. Select the requirement regarding the provision of an alternate for this flight -
Correct Answer (b) - no alternate is required providing the area forecast indicates no more then 4 eighths of cloud below LSALT + 500 feet and visibility not less than 8 km.
It also includes the answer explanation in the back,
31 - (b) - You can be sure that any aerodrome which has no TAF will have no instrument approach procedure other than a GPS NPA. Since a GPS NPA is ignored (actually says ingored in the book
) when it comes to planning an alternate, the requirements for no TAF are the same as the requirements for no approach procedure. AIP ENR 1.1 para 73.3
So hey I'm going to go with Mr. Tait on this one, but only because that was my understanding in the first place and his explanation has backed it up.
Question 31
You are planning an IFR charter flight in VH-OZY into an aerodrome for which no TAF is available. Select the requirement regarding the provision of an alternate for this flight -
Correct Answer (b) - no alternate is required providing the area forecast indicates no more then 4 eighths of cloud below LSALT + 500 feet and visibility not less than 8 km.
It also includes the answer explanation in the back,
31 - (b) - You can be sure that any aerodrome which has no TAF will have no instrument approach procedure other than a GPS NPA. Since a GPS NPA is ignored (actually says ingored in the book
) when it comes to planning an alternate, the requirements for no TAF are the same as the requirements for no approach procedure. AIP ENR 1.1 para 73.3So hey I'm going to go with Mr. Tait on this one, but only because that was my understanding in the first place and his explanation has backed it up.
There are two paragraphs which appear to contradict or at least undermine each other;
AIP ENR 1.1-58 ALTERNATE AERODROMES states;
This appears to be a very solid statement which says no TAF, must have alternate. (and the use of "an" in a statement - "an –indefinite article
the form of a before an initial vowel sound" means you use it instead of "a" in front of a vowell, no legal ramification other than what is stated)
Paragraphs 58.2 onwards specifies the weather minimums, not forecast requirements. Whilst 58.2.12(c) does refer to LSALT +500 it does not state a TAF is not required to contradict 58.1.3.
The issue comes when compared to flight planning requirements in ENR 1.10. The opening statement has who this is applicable to;
ENR 1.10 Flight Plan Preparation states;
So applicability is to all VFR flights away from an airport (navs/cross country) and all IFR flights (including local air work). The 50nm day VFR rule is just a dispensation for nominating an alternate due to weather below the alternate minima, not absolving you from checking the weather.
The statement which then instills the confusion is now immediately after;
ENR 1.10-1.2 Forecasts
So now in the face of ENR 1.1-58.1.3 it states if there is no instrument procedure (do not confuse with no nav-aid) you do not require an alternate due to lack of aerodrome forecast.
In answer to the original question an alternate is definitely required as there is an RNAV based instrument procedure and the aerodrome has no TAF service.
However there are the other discussions regarding the use of the area forecast when there's no instrument procedure (IFR or VFR). This can be used but it is an extremely blunt instrument and will more often then not result in an alternate being required anyway. There is a lot of discusion regarding cloud below LSALT +500 but that is only one part of the alternate minimums. Visibility, weather phenomenon and wind componants are all vital and usually very vague on the ARFOR. For instance on the Darwin sector ARFOR it forecasts isolated smoke reducing vis to 7km (VMC but below 8km alternate minima). It does not specify any specific location at all so i'm assuming you would need an alternate for everywhere within that area without a TAF that states theres no smoke there.
That being said ENR 1.1 58.1.3 is a very straightforward statement and could be a tricky one to overcome if you just happen to run out of fuel due weather whilst operating to a no-procedure aerodrome with min fuel.
With regard to this;
Considering a GPS NPA is an instrument approach procedure i'm not sure how this conclusion could be achieved without further reference to say it may be ignored.
AIP ENR 1.1-58 ALTERNATE AERODROMES states;
58.1.3 When an aerodrome forecast is not available or is "provisional", the pilot in command must make provision for a suitable alternate that has a firm forecast.
the form of a before an initial vowel sound" means you use it instead of "a" in front of a vowell, no legal ramification other than what is stated)
Paragraphs 58.2 onwards specifies the weather minimums, not forecast requirements. Whilst 58.2.12(c) does refer to LSALT +500 it does not state a TAF is not required to contradict 58.1.3.
The issue comes when compared to flight planning requirements in ENR 1.10. The opening statement has who this is applicable to;
ENR 1.10 Flight Plan Preparation states;
.......in the case of all flights away from the vicinity of an aerodrome, flights over water and all IFR flights, must make a careful study of:
a. current weather reports and forecasts for the route to be flown (ARFOR) and the aerodromes to be used(TAF);
......(the rest not relevent to the discussion)
a. current weather reports and forecasts for the route to be flown (ARFOR) and the aerodromes to be used(TAF);
......(the rest not relevent to the discussion)
So applicability is to all VFR flights away from an airport (navs/cross country) and all IFR flights (including local air work). The 50nm day VFR rule is just a dispensation for nominating an alternate due to weather below the alternate minima, not absolving you from checking the weather.
The statement which then instills the confusion is now immediately after;
ENR 1.10-1.2 Forecasts
1.2.1 A forecast must be either a flight forecast or an area forecast with an aerodrome forecast (TAF) for the destination and, when required, the alternate aerodrome. For a flight to a destination for which a pre-scribed instrument approach procedure does not exist, the minimum requirement is an Area Forecast.
In answer to the original question an alternate is definitely required as there is an RNAV based instrument procedure and the aerodrome has no TAF service.
However there are the other discussions regarding the use of the area forecast when there's no instrument procedure (IFR or VFR). This can be used but it is an extremely blunt instrument and will more often then not result in an alternate being required anyway. There is a lot of discusion regarding cloud below LSALT +500 but that is only one part of the alternate minimums. Visibility, weather phenomenon and wind componants are all vital and usually very vague on the ARFOR. For instance on the Darwin sector ARFOR it forecasts isolated smoke reducing vis to 7km (VMC but below 8km alternate minima). It does not specify any specific location at all so i'm assuming you would need an alternate for everywhere within that area without a TAF that states theres no smoke there.
That being said ENR 1.1 58.1.3 is a very straightforward statement and could be a tricky one to overcome if you just happen to run out of fuel due weather whilst operating to a no-procedure aerodrome with min fuel.
With regard to this;
31 - (b) - You can be sure that any aerodrome which has no TAF will have no instrument approach procedure other than a GPS NPA. Since a GPS NPA is ignored (actually says ingored in the book ) when it comes to planning an alternate, the requirements for no TAF are the same as the requirements for no approach procedure. AIP ENR 1.1 para 73.3
) when it comes to planning an alternate, the requirements for no TAF are the same as the requirements for no approach procedure. AIP ENR 1.1 para 73.3
Last edited by 43Inches; 23rd Jun 2011 at 06:55.
43 Inches, AIP GEN 1.5 para 8.5.5.4 see table and Notes 3 and 4
What this means is that if you do not have the relevent approved GPS reciever your destination becomes a "no-aid" destination, not a "no procedure" destination. You can still go to the destination and conduct a GPS approach but can not use the system to satisfy nav-aid alternate requirements.
Last edited by 43Inches; 23rd Jun 2011 at 08:27.
Another alternate question.
You are flying to a destination with an RNAv and the area forecasts indicates and approach may be required. (No TAF, 1x TSO 129, no ground based aids). Plan for an alternate.
Does your alternate require a ground based aid? Does day/night make a difference? There is an RNAV available and a TAF indicating visual approach conditions.
You are flying to a destination with an RNAv and the area forecasts indicates and approach may be required. (No TAF, 1x TSO 129, no ground based aids). Plan for an alternate.
Does your alternate require a ground based aid? Does day/night make a difference? There is an RNAV available and a TAF indicating visual approach conditions.
When you live....
Another alternate question.
You are flying to a destination with an RNAv and the area forecasts indicates and approach may be required. (No TAF, 1x TSO 129, no ground based aids). Plan for an alternate.
Does your alternate require a ground based aid? Does day/night make a difference? There is an RNAV available and a TAF indicating visual approach conditions.
You are flying to a destination with an RNAv and the area forecasts indicates and approach may be required. (No TAF, 1x TSO 129, no ground based aids). Plan for an alternate.
Does your alternate require a ground based aid? Does day/night make a difference? There is an RNAV available and a TAF indicating visual approach conditions.
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If you only have a TSO C129 then the alternate must have a ground based navaid and approach if the weather at the alternate would not allow a visual approach (Check out CAAP 179 page 47 for a useful flow chart).
I don't think it being day or night would change this as it is a weather related requirement and not a lighting requirement.
If you had a TSO C145 receiver (2 of them if CHTR or RPT) with a valid FDE prediction then you wouldn't have a problem nominating an alternate with just an RNAV provided the weather was at or above the alternate minima for that approach.
I don't think it being day or night would change this as it is a weather related requirement and not a lighting requirement.
If you had a TSO C145 receiver (2 of them if CHTR or RPT) with a valid FDE prediction then you wouldn't have a problem nominating an alternate with just an RNAV provided the weather was at or above the alternate minima for that approach.
