IREX Theory (Alternates)

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Hi everyone, I am studying IREX at the moment and have a question regarding alternates and holding.

The AIP's state that if the forecast is endorsed with an inter or tempo whereby cloud or vis reduces below the alternate minima then the pilot must either nominate an alternate or carry the applicable holding fuel.

However what happens if there is an inter or tempo and cloud and vis remains ABOVE the alternate minima?

Is the pilot still required to carry the holding fuel even though no alternate is required?

Thanks in advance

NP:confused:

[Stiff Under Carriage]

No, if the forcast conditions within the TEMPO or INTER are above the alternate minima, no holding or alternate fuel is required, unless the TEMPO or INTER is endorsed with THUNDERSTORMS.

[DraggingAir]

"The AIP's state that if the forecast is endorsed with an inter or tempo whereby cloud or vis reduces below the alternate minima then the pilot must either nominate an alternate or carry the applicable holding fuel. However what happens if there is an inter or tempo and cloud and vis remains ABOVE the alternate minima?"

As you correctly stated, the operational requirement relates to weather below the alternate minima. There is no requirement stated for weather above the minima.

There are two references in AIP that relate to your question.

1) What is an INTER or TEMPO?

AIP provides a definition of INTER and TEMPO in GEN 3.6.5 "...significant variations of a temporary or intermittent nature..."

The variation(s) could be weather that is improving or deteriorating.

2) When is holding fuel required?

AIP sets out a requirement for holding fuel when the variation mentioned in GEN is one that is a deterioration below certain criteria.

AIP ENR 1.1 73.2.4 "...intermittent or temporary deteriorations..."

So, it is possible to have an INTER or TEMPO, but not have an operational (holding/alternate) requirement.

DA.

[flog]

Rule of thumb says that you need an alternate if one of three things happens:
1/ Cloud base below alternate minima
2/ Vis (including lights / lighting) below alternate minima
3/ Instruments both in the aircraft and available to use (RAIM, US, etc.) approporiate for the approach.

So in your case, you wouldn't need them unless TS are forecast in there somewhere.