wsmempson: The statistic that tells you all you really need to know is that there has not been one single instance of aircraft colliding with one another whilst flying in IMC OCAS since the second world war.
So other posters have said.
That sort of statistical analysis can lead to tears. That's exactly the sort of analysis that lead to the space shuttle disaster. Very low probability but with a disastrous outcome. As I see it it's a bit like Russian Roulette. I can imagine the uproar if such an accident ever happened.
fisbangwallop
It's the same here, IFR flights have no protection outside CA. Once outside of controlled airspace there will be no traffic info based on radar plots, the ATC unit providing radio coverage doesn't have that info. Traffic information is passed on by an area information ATC unit based on the IFR plans in the system and position reports from airborne aircraft.
Yes I'm well aware of the difference between IFR and IMC and VFR and VMC. This is what triggered my original post in this thread. It seemed to me that someone was apparently flying on VFR rules but actually going IMC.
The CAR's in New Zealand state
Visual Flight Rules
91.301 VFR meteorological minima
(a) Except as provided in rule 91.303, and paragraphs (b) and (c), a pilot-in-command must not operate an aircraft under VFR—
(1) when the flight visibility is less than that prescribed for the corresponding class of airspace in Table 4; or
(2) at a distance from clouds that is less than that prescribed for the corresponding class of airspace in Table 4.
(b) Except as provided in rule 91.303, a pilot-in-command must not takeoff or land an aircraft, or fly in the vicinity of an aerodrome, under VFR when the flight visibility, or the cloud ceiling, is less than—
(1) at aerodromes within a control zone, that prescribed in Table 5; and
(2) at aerodromes in uncontrolled airspace, that prescribed in Table 6.
(c) A pilot-in-command of—
(1) a helicopter may operate in Class G airspace with a flight visibility of less than 5 km if manoeuvred at a speed that gives adequate opportunity to observe other traffic or any obstructions in order to avoid collisions
For Class G airspace (uncontrolled) Table 4 states
Above 3000 feet AMSL or 1000 feet above terrain whichever is the higher,
2 km horizontally, 1000 feet vertically, visibility, 5 km below 10,000 ft, 8 km above 10,000.
At or below 3000 feet AMSL or 1000 feet above the terrain whichever is the higher
Clear of cloud and in sight of the surface, 5 km visibility
The exceptions in rule 903 referred to above do not relate to uncontrolled airspace.
If you cannot meet the VFR minima you need to comply with IFR rules and the IFR rules state
Instrument Flight Rules
91.407 IFR flight plan
(a) A pilot-in-command of an aircraft must—
(1) submit a flight plan to an appropriate ATS unit prior to any flight under IFR;
As I have since learned you guys don't need to be on an IFR plan to fly IFR.