LOW VIS Operations

[scramjet]

When does ATC decide when to implement Low Visibility Operations at an Airport?

Today in Brisbane they had Low vis operations with 2000m vis (I think).
From company sim training I had always taken low vis operations as being less than 500m vis (when it is Capt only take off)

Couldn't seem to find anything in Jepps- (Though of course that doesnt mean its not there) references greatly appreciated

Thanks

[89 steps to heaven]

At Mackay, low vis operations are implemented at 800m vis. This also is the cut off for operations as the lighting backup power does not meet the requirements for operations down to 500m vis.

[VH-XXX]

I assume you are referring to IFR rather than special VFR? Special VFR would be around 3k minimum.

[Green gorilla]

I have had ATC say special VFR but reduced VIS may the same as expect instrument approach.

[VH-XXX]

Anyways if you are referring to special VFR, 3km would be the absolute minimum and you would want to make absolutely sure that you know it's better than 3k vis once you are outside the gaap or C or where-ever you are.

What really P:mad:es me off is when I may request a special VFR departure which happens a fair bit in Melbourne I get some clown butting in and telling the tower that operations are not suitable for VFR. No identification, no callsign, just comments that are very unhelpful. That's when I have to reply with SPECIAL VFR thanks Mr. Loser as I depart.

[Pera]

Each aerodrome has it's own rules based on equipment (eg lighting) and local factors.

IMHO low vis ops refers to movement around an aerodrome, not whether VMC exists.

[joeyjojo]

Currently, the requirements pertaining to aircraft operator take-off and landing minima are specified in CAR 257, AIP Enroute 1.5, or as conditions attached to an exemption issued to an airline operator. The standards for aerodrome facilities and procedures are specified in the Manual of Standards (MOS Part 139). The standards for Air Traffic Service are specified in MOS 172, but it does not contain specific low visibility standards or requirements.
ATC at each aerodrome develop its own low visibility procedures. ATC only provide the meteorological information to pilots and the decision to conduct a low visibility operation rests with the pilot.
CASA through the AIP, allows IFR (generally RPT) aircraft to take-off with 500m visibility at any aerodrome that has 60m spaced runway edge lights – ATC controlled or non-controlled. MOS Part 139 requirement, in accordance with ICAO Annex 14, is that aerodromes used in take-off below 800m RVR is to be provided with standby power for runway lighting with the capability of 1 second switch over time. In Australia, this is not provided at aerodromes without ATC presence. There may be a case to relax the aerodrome requirement if the standby power facility is not really required to support the take-off operation.
Currently, AIP Enroute 1.5 specified take-off visibility minima down to 500m. Major airlines have been given exemptions to take-off with 400m RVR if the aerodrome edge light spacing is not more than 60m and to take-off with 300m RVR if the runway edge lights and centre line lights were available (light spacing is not indicated in the AIP - Enroute Supplement). The 300m RVR is at variance with ICAO, the JAA and FAA which require runways used in take-off in RVR of below 350m to have Cat II or III aerodrome movement area lighting, viz. high intensity runway edge and centre line lights and taxiway lights. The exemptions are granted to airlines subject to a range of requirements on the flight crew, but no specific requirements on the ATC or the aerodrome operator. CASA has no guidance for issuing such approvals and tying together the aerodrome operators, ATC and the airline operators.
Annex 14 requires the runway holding positions of a runway used in RVR of less than 550m to be provided with stop bars unless appropriate aids and procedures are available to assist in preventing inadvertent incursions of aircraft and vehicles, otherwise the aircraft on the manoeuvring area are to be limited to one at a time, and vehicles on the manoeuvring area are limited to the essential minimum. Currently, there are no stop bars at Australian aerodromes and the ATC do not limit aircraft to one at a time in less than 550 RVR. Appropriate aids and procedures are not defined or documented. Some major aerodrome operators are concerned of possible liability on their part in allowing their aerodromes to be used in RVR of less than 550m with no stop bars, as there is no assurance that appropriate aids and procedures are in place. Currently, at each aerodrome, the aerodrome operator and ATC develop their own procedures.

[Tidbinbilla]

Simply put - whenever visibility is below 800m.

TID

[ForkTailedDrKiller]

Simply put - whenever visibility is below 800m

I thought I had put it much more simply than that!

Dr :8