Header1200x385

facebook_page_plugin
× Welcome to the IREX question and answer forum. Please feel free to post your questions but more importantly also suggest answers for your forum colleagues. Bob himself or one of the other tutors will get to your question as soon as we can.

TAF question- Alternate requirements

  • SteveS
  • Topic Author

SteveS created the topic: TAF question- Alternate requirements

Hi all,

Could anyone please shed some light as to why these conditions are below the alternate minima? As I understood it, cloud more than 4/8ths and visibility below alternate minima. As stated in the TAF, there is cloud below the alternate minima but none more than 4/8ths. Should the answer for this question be A instead of C?

Thanks in advance.


#1
Attachments:

Please Log in or Create an account to join the conversation.

  • Posts: 138
  • Thank you received: 15

Bosi72 replied the topic: TAF question- Alternate requirements

The answer is in ENR 1.1 10.7.2.3, but also read whole 10.7.2 paragraph.

As you know, the weather doesn't change instantaneously at exact minute. It is assumed it takes 30mins to change.

When the forecast changes from bad to good weather, you have to take away 30min from the >good< weather to ensure conditions will be good.

When the forecast changes from good to bad weather, you also have to take away 30mins from >good< weather to ensure the weather will be good.

So, always take away 30mins from the good weather.

Also FEW+SCT=BKN

Hope above helps
#2
The following user(s) said Thank You: SteveS

Please Log in or Create an account to join the conversation.

  • Posts: 2446
  • Thank you received: 257

bobtait replied the topic: TAF question- Alternate requirements

The aternate minima for this aerodrome is 1200ft. The SCT cloud is at 1000ft and the FEW cloud is at 800ft. Since SCT is 3/8 to 4/8, and FEW is 1/8 to 2/8, the total could be as much as 6/8 at different levels below the alternate minima. If FEW and SCT exist below the alternate minima, you must consider the cumulative effect. See AIP ENR 1.1 para 10.7.2.1 (a).

Bob
#3
The following user(s) said Thank You: SteveS

Please Log in or Create an account to join the conversation.

  • Posts: 1
  • Thank you received: 0

Gerard replied the topic: TAF question- Alternate requirements

You are arriving at 0410 which is not 30 min after the end of preceding period to 0400 therefore if you can carry 20 minutes holding fuel to 0430 you will no longer require an alternate
Gerard
#4

Please Log in or Create an account to join the conversation.

Time to create page: 0.138 seconds