Awo Euops
 

Hy guys,

I have a doubt about the "new" interpretation of low vis proc, in particular the vis/rvr convertion table.
I can use this table only if rvr is not reported and rvr required is 800m or more.
Now this is the situation:
1.ils cat 1 at night with all the HIALS rvr required 550.
With rvr reported at 550, I land
Without rvr reported and vis 500m, I can't land....is that correct??

2.ils cat1 at night with all the HIALS rvr required 900
With rvr reported at 900, I land
Without rvr reported and vis 450m, I use the famous table and I land...is that correct??

Probably there is something that I don't understand...

Thanks for your help
Michelda

Ops 1.430
 

Hi,

All correct...in EU world.

In some States, you can find a separate minimums listing. For the same RWY, you can have different minimum values. One for RVR (noted Rxxx), one for visibility (Vxxx) and in some cases one for converted met vis (Cxxx).

If those values are all identical, no prefix is attached to the value and then VIS has to be used without conversion if RVR is not reported.

If those values differ (R, V charted together), VIS has to be used without conversion if RVR not reported.

Hope it's clear :8

Hy shortfuel

but something is strange.....
usually an higher minima is created because you have some obstacles in the approach or go around sectors. So in the second case you have "more significant" obstacles and with a lower visibility than an ils "without" obstacles you can start your approach.....

thank you for your answer
Michelda

Sure about this?

EU OPS says:

"Conversion of reported meteorological visibility to RVR
1. An operator must ensure that a meteorological visibility to RVR conversion is not used for calculating take-off
minima, Category II or III minima or when a reported RVR is available.

Note: If the RVR is reported as being above the maximum value assessed by the aerodrome operator, e.g. “RVR more than
1 500 metres”, it is not considered to be a reported RVR in this context and the Conversion Table may be used.

2. When converting meteorological visibility to RVR in all other circumstances than those in subparagraph (h)1.
above, an operator must ensure that the following Table is used:"

Hy breakthesilence

that is the old 1.430. there is a new one. Your company could decide to improve it in July 2011 (I don't remember the day...I guess 16th)

ciao
Michelda

I looked for a new issue of the EU OPS but I found only that one.
The airline I work for is still using JAA minimums (so the Jeppesen table called JAA MINIMUMS instead of the STANDARD at the bottom of the approach charts). Have you a link to the new EU ops?

It still says what i wrote before :O

I don't think you have red a lot of times it:O
Pag 84

I didn't imagine there were 2 sections in the same document!

However, when the time to apply these procedures will come, the airline (i guess yours too) will provide all the informations you need :}

Hi all!

In my company we have chenge to the NEW eu-ops and we have the same problem to understand exactly this part of the NEW 1.430 about the new conversion logic fo vis/RVR (or CVR). :ugh:

Any idea in your companies ?

Hi topper80

Welcome on board

OK, here's my take on your question......

You cannot convert a met viz to RVR (converted met viz or CMV) to a value lower than 800m. So your first example of night with HIALS enables the met viz to be converted by a factor of 2.
2 x 500m = 1000m CMV and you can make an approach.

If the met viz was less than 400m, i.e. by multiplying by 2 it comes to less than 800m CMV it is invalid.

Therefore a simple rule of thumb for a night approach with HIALS requires a met viz of 400m to be converted to a CMV of 800m for all approaches requiring 550/600/650/700/750 or 800 RVR.

To answer your questions, you can make an approach in both of your scenarios.

By day with HIALS you multiply the met viz by 1.5 instead of 2.

Hope this helps (well, it's certainly my understanding, but I'm always keen to learn),

Sid :)

I disagree Sid. English is not my native language but I also checked the French version of EU-OPS to be sure.

If your required RVR is < 800m then conversion shall not be used in any case.

So in our OP first example, landing is not a legal option if RVR is not reported.


Michelda,

I see your point and what could seem strange. But don't forget that in the second case, if let's say your required RVR is 900m, your associated DA will be well above 200ft (closer to about 400ft AAL) where in the first case it most probably is 200ft.

Hy short fuel

With new euops, mda almost doesn't exist.
In flight, you don't need ceiling to start the approach. In my opinion, it is strange that you can start your approach in the second case and not in the first one.

Michelda

Edited to make you happy :8

I tend to forget a lot but I think I remember that one :E

Now I can sleep well:O:O:O

Danke

Michelda

So : I can NEVER use the conversion table for procedures that REQUIRE rvr <800m? Can't I land without RVR report??? :ugh::ugh::ugh:

With regard strictly to EU-OPS new appendix, that is correct.

But some EU States do not apply EU regulations directly. Those regulations have to be incorporated in national laws. That takes time.

The best thing to do is to check your Operations Manual, that has been approved by your Authority, that is the controlling document.

I would have to agree with SidHolding. According to my approach plate provider, their Legend section states the following:

"A conversion of MET visibility possibly given is allowed as long as the resulting RVR/CMV after conversion is equal to or higher than 800m."

Our ops manual has not yet been amended - we're still using JAR-OPS minima (due to change soon).

Hope this helps.

Fly