Approach CAT I

[Johnwayne]

Good evening everbody
i have a doubt and i am looking some help to clarify: if i have a metar of an airport like this : vrb02 kts rvr 550m vv001 , i am allowed to start the approach despite the ceiling vlue?
or better (i know jar ops#430) the controller can consider that airport good for CAT I APP even if only the rvr is according minima and not ceiling?
Please help me.
And the controller can clear me even if the min rvr reported on jeppesen chart is 800m and is giving me 550m? In that case i have to divert is it correct?:confused:

[Lemper]

Unless the approach chart specifies "CEILING REQUIRED", yes you can start the approach. The ATC will clear you for approach, but at some (big) airport, LVP may be enforced, which will not affect your approach as long as the Wx remains at or above minima. BTW, Vertical Visibility is NOT a ceiling!

[Spitoon]

Can't give you the answer to this but here is a UK ATC view.

First, the vv001 is not a cloud ceiling value but a vertical visibility, which implies that there is no measurable ceiling. Second, ATC does not concern itself about what minima the pilot may need (although most controllers have a pretty good idea of CAT I minima) but rather tells the pilot what the conditions are and then will ask for the pilot's intentions, i.e. pilot makes the decision and ATC will do whatever it can to accommodate the pilot's wishes.

Hope this is some help.

[RYR-738-JOCKEY]

The reported vv would serve as a ceiling in my world, and should be above your required ceiling (for non-precision). But vv is used when ceiling is typically below 500' and when it's difficult to judge because of precipitation.

From my personal experience, ATC is not taking the decision for you, which sometimes would be appropriate in my view. For instance you're doing a CATIIIa approach at night, RVR is 350 and then the touchdown zone lights fails. The controller should both know that the required RVR is then 550, and more importantly advise every aircraft of this ("..below minimums.."). I get the feeling they just leave it to us to decide, 'cause they won't get in trouble anyway...
ATC is there to help us out, but I have noticed that they can sometimes report wx to be at minimums just to give us a chance. Especially when it comes to wind, which is very difficult to report because it changes all the time when it's gusty and close or above limits. It's not much of a help when you get a report of max x-wind and you're not able to align in the flare.

[Bob Lenahan]

CAT I Approach minimums are based on visibility at the time of crossing the faf.
bl

[p_bakes]

RYR-738-JOCKEY, you mention that....

RVR is 350 and then the touchdown zone lights fails. The controller should both know that the required RVR is then 550, and more importantly advise every aircraft of this ("..below minimums..").

I would suggest that the reason the controller doesn't make a sweeping statement like that is because the minima can be different for different operators/types.

If the above case happened to me, all I need to do is adjust required RVR to 300m, not 550m. It would be a bit time consuming to for a controller to have to dig out details of each individual arrival's required minima, so they just leave it up to the pilots.

pbakes

[RYR-738-JOCKEY]

p_bakes: Are you sure? I believe the JAR-OPS required RVR is 550 night and 300 day for given situation...But, I enjoy being a bit provocative in order to get some inputs. :E

[Spitoon]

ATC is not taking the decision for you, which sometimes would be appropriate in my view. For instance you're doing a CATIIIa approach at night, RVR is 350 and then the touchdown zone lights fails. The controller should both know that the required RVR is then 550, and more importantly advise every aircraft of this ("..below minimums.."). I get the feeling they just leave it to us to decide, 'cause they won't get in trouble anyway...
Maybe you're being provocative but, certainly in my part of the world, this is the reverse of what ATC does. The commander, as is often pointed out when any suggestion is made to the contrary, is responsible for managing his or her aircraft and making decisions on the basis of all the relevant information. The UK has dipped its toe into getting ATC to tell pilots when they are about to make an approach below minimum - the so called absolute minima procedure - and it is hugely confusing and widely misunderstood. And it doesn't apply in CAT II/III because of the different minima that different operators have.
ATC is there to help us out, but I have noticed that they can sometimes report wx to be at minimums just to give us a chance. Especially when it comes to wind, which is very difficult to report because it changes all the time when it's gusty and close or above limits. It's not much of a help when you get a report of max x-wind and you're not able to align in the flare.Maybe, but can you be sure? Most of the data that is passed to pilots is recorded and it would be a foolish controller who misrepresents the data to a pilot. But if you think it's the case - and, who knows, it could be inaccurate sensing equipment - there are ways to report it. Each State across the EU now has to have a safety occurrence reporting system - use it.

[p_bakes]

RYR-738-JOCKEY,

sorry you're figures are quite correct for a CATIIIA approach, I was thinking about the CATIIIB figures, should have read your wording a bit more carefully! However my point stands that how does the controller know what each aircrafts limits are? What if the crew have unwittingly let their autoland currency lapse? so many variables that it's not worth leaving the decision making to the controllers.

pbakes

[Henry VIII]

Good evening everbody
i have a doubt and i am looking some help to clarify: if i have a metar of an airport like this : vrb02 kts rvr 550m vv001 , i am allowed to start the approach despite the ceiling vlue?
or better (i know jar ops#430) the controller can consider that airport good for CAT I APP even if only the rvr is according minima and not ceiling?
Please help me.
And the controller can clear me even if the min rvr reported on jeppesen chart is 800m and is giving me 550m? In that case i have to divert is it correct?:confused:
My company (Europe) according JAR rules allows to start the approach regardless of the wx report. The go-no-go gate is the OM or equivalent position; at that stage the wx report MUST be at or above the required one. After that point we can continue down to the minima to search for rwy visual contact.
I agree that vv is not to be considered a ceiling.
ATC do not know each company minima stated in the OM part C.
800 mt are referred to general visibility, 550 to rvr.
Controller will clear you unless LVP in progress (vis. blw 400 mt.).

From my point of view I prefer to continue the approach, unless other consideration(s) affecting fuel, safety, altn airport and park availability, etc. takes priority.

HVIII

[I-2021]

The go-no-go gate is the OM or equivalent position;

Are you sure about that ? If the weather goes below minima after the beginning of the approach the OM becomes your go/no go gate.

[wheresthecoffee]

Henry is spot on, if there is an OM.

If not, use 1000' aal.

[RYR-738-JOCKEY]

OM, or FAF, or 1000' AAL, me thinks.

[bookworm]

p_bakes: Are you sure? I believe the JAR-OPS required RVR is 550 night and 300 day for given situation...But, I enjoy being a bit provocative in order to get some inputs. :E

We don't all operate to JAR-OPS1.

[FlapsOne]

738

Jar Ops 1.405 makes no mention of FAF - prob cos it's normally too far out.

OM or equivalent position or 1000' above aerodrome are the only points mentioned.

[212man]

I think the expression we are looking for is "Approach Ban"

[FlapsOne]

Well, maybe - but that expression doesn't feature in the Jar Docs at all.
JAR-OPS 1.405 Commencement and
continuation of approach

(a) The commander or the pilot to whom
conduct of the flight has been delegated may
commence an instrument approach regardless of the
reported RVR/Visibility but the approach shall not
be continued beyond the outer marker, or equivalent
position, if the reported RVR/visibility is less than
the applicable minima. (See IEM OPS 1.405(a).)
(b) Where RVR is not available, RVR values
may be derived by converting the reported visibility
in accordance with Appendix 1 to JAR-OPS 1.430,
sub-paragraph (h).

(c) If, after passing the outer marker or
equivalent position in accordance with (a) above, the
reported RVR/visibility falls below the applicable
minimum, the approach may be continued to DA/H
or MDA/H.

(d) Where no outer marker or equivalent
position exists, the commander or the pilot to whom
conduct of the flight has been delegated shall make
the decision to continue or abandon the approach
before descending below 1 000 ft above the
aerodrome on the final approach segment. If the
MDA/H is at or above 1 000 ft above the
aerodrome, the operator shall establish a height,
for each approach procedure, below which the
approach shall not be continued if the

RVR/visibility is less than the applicable minima.
(e) The approach may be continued below
DA/H or MDA/H and the landing may be completed
provided that the required visual reference is
established at the DA/H or MDA/H and is
maintained.

(f) The touch-down zone RVR is always
controlling. If reported and relevant, the mid point
and stop end RVR are also controlling. The
minimum RVR value for the mid-point is 125 m or
the RVR required for the touch-down zone if less,
and 75 m for the stop-end. For aeroplanes equipped
with a roll-out guidance or control system, the
minimum RVR value for the mid-point is 75 m.

[RYR-738-JOCKEY]

FlapsOne: I thought the "equivalent position" was FAF. OM for precision approach. FAF for non-precision. But if no OM, then the point where you intercept GS from platform alt can be defined as FAF. And finally for approaches with neither, then use 1000' AAL...

[I-2021]

Thanks FlapsOne:ok: