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View Full Version : Minima ? what is going on out there?


Thanos1970
14th Jan 2008, 01:22
Hi, i was commuting to Prague this evening, and when we landed, i could not see the wing, so i cross checked RVR and Cat 2 min.

Arrival 2142Z
Metar 132120 02003KT 0150 R24/0225N R31/0175N FZFG VV001 M02/M01 Q1016

Cat 2 min RwY 24 300 RVR.(unless N-registered)


whow about approach ban?????????????

What is going on ?

OsPi
14th Jan 2008, 02:54
LKPR 132200Z 07003KT 0150 R24/0225N R31/0200N FZFG VV001 M02/M02 Q1017 0615//95 1319//95 NOSIG
LKPR 132130Z 02002KT 0150 R24/0225N R31/0175N FZFG VV001 M01/M02 Q1017 0615//95 1319//95 NOSIG
LKPR 132100Z 35002KT 0150 R24/0250N R31/0200N FZFG VV001 M02/M02 Q1018 0615//95 1319//95 NOSIG

Seems like RVR was below 300 meters most of the time. What runway did you use?

With calm winds like that landing in any direction would be possible, and runway 24 is CATIII approved.

Speevy
14th Jan 2008, 03:01
24 is the preferential rwy in lvps in PRG...
So I would say it was a 24 landing in Cat III
Speevy

dolly737
14th Jan 2008, 07:31
The deciding RVR values are those communicated by ATC just before the Outer Marker, not the METAR.

Right Way Up
14th Jan 2008, 08:10
Thanos,
Before getting too excited and not a little accusatory, you should check the facts.

Prg 24 is a Cat III runway. :rolleyes:

BTW you should have been able to see the wing, I suggest the windows were obscured.

AltFlaps
14th Jan 2008, 08:34
Yo Thanos,

Unless you were sitting at the point end ... you don't know what went on.
You can do a CAT IIIb onto R24 at PRG, and that requires only 75m.

Let the the boys do their job up front and you just sit and enjoy your gin and tonic in the back !

If you feel you can't trust the crew to fly you there, then I suggest you drive in future :*

SmokeAndNoise
14th Jan 2008, 09:07
Remember that the 150m from the metar are met vis. It's not uncommon to have a much better actual RVR even with a fairly low met vis like this..

Hot Wings
14th Jan 2008, 09:18
When there is an R in front of the runway then that means that it is an RVR and the N means no change (not North!). U would mean RVR increasing and D decreasing.

Dunhovrin
14th Jan 2008, 10:02
i (sic) could not see the wing

Did you have a window seat?

Maude Charlee
14th Jan 2008, 10:18
I would suggest that a quick 'back to basics' course in how aeroplanes land on runways would be in order if we're trying to guage RVR by looking out along the wing. Are you familiar with the direction it points in with regard to the landing direction? :ugh:

Shot Nancy
14th Jan 2008, 11:10
When there is an R in front of the runway then that means that it is an RVR and the N means no change (not North!). U would mean RVR increasing and D decreasing.

RVR past tendancy: U (up), D (down), or N (no change).

I think we are all being wound up.

Julian Hensey
14th Jan 2008, 11:37
I can confirm with a friend of mine who flew into Prague that the wing edge was not visible, and the end of it could only be seen when the lights were turned on and the light could be seen.

FlightDetent
14th Jan 2008, 11:38
whow about approach ban?????????????

There is no such thing as an approach ban in Czech. Welcome to the world outside UK. It is operator's/commander's responsibility to observe applicable minima and procedures. Prague RWY 24 is CAT IIIb ICAO, European minima are:

C3b RVR 75 m
C3a RVR 200 m
C2 RVR 300 m.

If your aircraft was equipped for C III and crew approved to execute such approaches, which I suppose so, all worked as advertised. Your airline is proud to have safely brought you to the destination in such poor weather, and quite rightly so. Job well done.

FD (the un-real)

Right Way Up
14th Jan 2008, 12:04
FD,
Approach ban is not a UK limitation it is a JAR one. (1.405) The term is an old one but still applies that you cannot pass the marker or equivalent point unless the RVR is equal or better to minima.

Bluasfly
14th Jan 2008, 13:26
ALTFLAPS
I have been flying heavy aircraft for many years and the cat3b limit has been 100m the 75m has been the stop end limit and not the threshhold or mid point limit, you must be flying something very special.

A4
14th Jan 2008, 13:46
Bluasfly,

I fly the Airbus narrow body series (A319/20/21) and we operate to CAT 3B with RVR requirement of 75m and NO Decision height.

The worst RVR I've ever landed in was 100/100/100 but the Met Viz on the ATIS was 25m :eek: (had to listen twice to make sure we heard it correctly). The landing was normal but the taxiing from the runway to stand was VERY slow - 25m was probably about right.

Sounds to me like the PRG flight was all operated correctly in accordance with JAR-OPS.

A4

PS The CFM56 doesn't like taxiing in FZFG - I've never seen Fan blade icing accumulate so quickly even with EAI on.

A4

Hahn
14th Jan 2008, 14:28
Th fan blades pick up ice because they are not deiced. Engine a/i heats only the good old intake......

A4
14th Jan 2008, 15:21
Hello Hahn

Yes, I appreciate that but the CFM-56 on the A319 does seem to aquire blade ice very quickly. Engineers have told me that the same engine on the B737 series does not aquire ice at anywhere near the same rate. It's been a while but I don't recall it being a problem on the V2500's either.

I recall landing in FZFG. It was "CAVOK" on top and the fog tops were about 600 feet agl, surface temp -3. By the time we were on stand perhaps after 7-8 minutes in the fog each blade had approx 2-3mm of ice on the back of the blades - not easily noticeable on a dark, foggy and cold walk round.

Engineers did their best but during the 15 second run up prior to departure the N1 vibs hit 6.5 momentarily before settling down to <1 - and off we went.

A4

sleeper
14th Jan 2008, 16:54
Also flying Heavy, (immaterial) but cat IIIb needs 75 m not 100m. Must be a company thing.

fox niner
14th Jan 2008, 17:42
Yep. For me 75 meters of RVR are enough to land in cat IIIB. I heard that the 75 meters RVR are there to enable the pilots to vacate the runway AFTER landing, and taxi to the gate. The landing itself is irrelevant (as there is no DH)

Cat IIIC would be 0 RVR. This would mean you need an auto coupled guidance to the gate. this does not exist as we all know. But some time ago when the system was invented and all these different ILS integrities were made, it was contemplated.
It was considered too expensive, so hence there is no cat IIIC. (0 RVR requirement)

I guess the landing in prague was completely legal.

FlightDetent
15th Jan 2008, 09:34
FD,
Approach ban is not a UK limitation it is a JAR one. (1.405) The term is an old one but still applies that you cannot pass the marker or equivalent point unless the RVR is equal or better to minima.

We understand each other quite well. Yet there is no such thing as "approach ban" in JAR OPS 1.405. The OM/equivalent position requirement is a operator's procedure (a regulation-forced one). Let's keep the term "approach ban" for moments when ATC will refuse to issue an approach clearance, which is a UK thing. Savvy? ;)

Hot Wings
15th Jan 2008, 10:07
Shot Nancy,

Quote:
When there is an R in front of the runway then that means that it is an RVR and the N means no change (not North!). U would mean RVR increasing and D decreasing.

RVR past tendancy: U (up), D (down), or N (no change).

I think we are all being wound up.

Perhaps I should have added "RVR values since the last report"!

Who's winding up who?

Right Way Up
16th Jan 2008, 18:47
Savvy?

Not exactly when regarding Jar Ops! ;) but we are both on the same wavelength.

ATC don't ban you they just warn you that you will be landing below minima. Stolen from the locos landing below minima thread (from UK AIP)

4 If pilots state that it is their intention to commence an instrument approach and the reported RVR is below the Absolute Minimum,
ATC will issue a warning message as follows:
‘(Callsign) you are advised that the current RVR/visibility is (number) metres which is below the absolute minimum for a (name)
approach to runway (number). What are your intentions?’
4.1 If pilots indicate that it is their intention to continue the approach below 1000 ft above aerodrome level, ATC will pass the
following message:
‘(Callsign) if you continue the approach and descend below 1000 ft above aerodrome level, it is believed that you will be
contravening UK legislation and I shall be required to report the facts, acknowledge’.
This will be followed, at the appropriate moment, with:
‘(Callsign) there is no known traffic to affect you making a (name) approach to runway (number)’.
Subsequently, ATC controllers will not issue a landing clearance but will use the following phraseology at the appropriate time:
‘(Callsign) runway visual range (number) metres, there is no known traffic to affect you landing, surface wind (number) degrees
(number (knots))’.

Seems like a fair procedure. Might just stop you from making a big error.

FlightDetent
17th Jan 2008, 06:48
I stand corrected.