Lido Charts, question about minimums
Thread Starter
Joined: Feb 2012
Posts: 8
Likes: 0
From: belgium
Lido Charts, question about minimums
Hello,
I've a question for the Lido charts experts:
ILS 08 (Cat 1).
In the table, you can read, for cat C plane:
CAT 1 DME :
200 - 750
330
It means: DH: 200 ft, DA 330 ft, and ... 750 m
Now the ATIS: vis 300m , RVR 900m , VV200ft
Can I try to shoot the approch ?
Ok, we can disregard the DA and DH.
We only take care of vis / RVR, but in this case, visibility is below 750, but RVR above). So, what do you think ??
I will tell you my opinion after
Cheers
I've a question for the Lido charts experts:
ILS 08 (Cat 1).
In the table, you can read, for cat C plane:
CAT 1 DME :
200 - 750
330
It means: DH: 200 ft, DA 330 ft, and ... 750 m
Now the ATIS: vis 300m , RVR 900m , VV200ft
Can I try to shoot the approch ?
Ok, we can disregard the DA and DH.
We only take care of vis / RVR, but in this case, visibility is below 750, but RVR above). So, what do you think ??
I will tell you my opinion after
Cheers
Last edited by benmicolon; 6th November 2012 at 02:05.
Thread Starter
Joined: Feb 2012
Posts: 8
Likes: 0
From: belgium
Hello,
Thanks for your answer.
Yes of course vv is not revelant. Now, let's go into details,
My question is about the value "750" ...
In the lido charts, this distance could be written like:
case 1: 750
case2: 750V
case 3: 750R
case 4: 750R/550V
Each case is very different. According to lido introduction document.
Case 2: you need a visibility of 750m, no conversion possible
Case 3: you need an RVR of 750m. If RVR not availlable, then you can use the visibility , with no conversion.
Case 4: RVR must be above 750, visi can be disregarded. If RVR not reported, vis must be above 550 (no conversion possible)
and, our case, Case 1: no letter after the value, it means that we are talking about "RVR/CMV" (= a calculated RVR resulting from a calculated met visibility). Converting factor between 1 and 3 depending of day night, lighting etc. No conversion possible if the result is less than 800m. Conversion not allowed for CAT 2/3 app, for TO minima, or if an RVR is reported already.
In our case, the RVR is reported, so the conversion is not allowed. But it doesn't mean that you can use the RVR value. I understand : "take the vis, convert it, if allowed", take the result and compare it with the value, then decide if you can do the app".
It's a bit confusing, isn't it ?
Thanks for your answer.
Yes of course vv is not revelant. Now, let's go into details,
My question is about the value "750" ...
In the lido charts, this distance could be written like:
case 1: 750
case2: 750V
case 3: 750R
case 4: 750R/550V
Each case is very different. According to lido introduction document.
Case 2: you need a visibility of 750m, no conversion possible
Case 3: you need an RVR of 750m. If RVR not availlable, then you can use the visibility , with no conversion.
Case 4: RVR must be above 750, visi can be disregarded. If RVR not reported, vis must be above 550 (no conversion possible)
and, our case, Case 1: no letter after the value, it means that we are talking about "RVR/CMV" (= a calculated RVR resulting from a calculated met visibility). Converting factor between 1 and 3 depending of day night, lighting etc. No conversion possible if the result is less than 800m. Conversion not allowed for CAT 2/3 app, for TO minima, or if an RVR is reported already.
In our case, the RVR is reported, so the conversion is not allowed. But it doesn't mean that you can use the RVR value. I understand : "take the vis, convert it, if allowed", take the result and compare it with the value, then decide if you can do the app".
It's a bit confusing, isn't it ?
