Absolute min vis for departures?

[IO540]

There is the 1800m for IMC Rated pilots, under IFR, applicable to the UK only.

The same pilot (IMCR or IR) could depart "VFR" down to 1500m, which is quite funny because it's better than the above.

I read somewhere that there is NO minimum vis for IR pilots departing IFR (private flight, obviously). Is this true, for both G and N?

Also, is there a min vis for approaches, if no RVR is published for the airfield?

I know that airfields in CAS (Class D typically, and in Europe they will normally have full ATC) have written down departure limits for this; typically the min cloudbase is 1000-1500ft for a VFR departure. Presumably the RVR will apply to both departures and arrivals, VFR or IFR, no?

I am not referring to rules for N and within the USA.

One probably should know all this, but visibility isn't normally an issue. It's the cloudbase that normally gets you. Only once in several years did I have to wait for ATC to tell me the vis was above 1800m before I could go, under the IMCR privileges.

I recall an occassion, when I was doing the FAA PPL (in the UK) when I asked the examiner what the minima for the checkride were. He jumped on me straight away, but in the end neither myself nor the CFII instructor could find anything in the FAR/AIM for the airfield, which was in Class G. There was a 1000ft min cloudbase for Class D, but as I say above one would expect a min cloudbase for VFR ops at a towered field anyway.

(This question is another FAA/CAA rules mixture :O )

[chevvron]

Depnds on runway lighting configuration and ancillary lighting.
UK Minima is normally 400m, but can go below this; see AIP entries for details.

[IO540]

For private flight?

[bookworm]

There is the 1800m for IMC Rated pilots, under IFR, applicable to the UK only.

The same pilot (IMCR or IR) could depart "VFR" down to 1500m, which is quite funny because it's better than the above.


The 1800 m minimum visibility for take-off and landing for IMC-rated pilots is not limited to IFR.


I read somewhere that there is NO minimum vis for IR pilots departing IFR (private flight, obviously). Is this true, for both G and N?


Correct for G-reg. AD 1.1.2 3.4 refers


Also, is there a min vis for approaches, if no RVR is published for the airfield?


If no RVR is given, the equivalent must be calculated from met vis. AD 1.1.2 7.2 refers.

I know that airfields in CAS (Class D typically, and in Europe they will normally have full ATC) have written down departure limits for this; typically the min cloudbase is 1000-1500ft for a VFR departure. Presumably the RVR will apply to both departures and arrivals, VFR or IFR, no?

Rule 24(3) requires a pilot to use the reported visibility, and VFR will not be permitted if that is less than 5000 m. Since no cloud separation is required for VFR in class D in the UK, the ICAO 1500 ft minimum ceiling is not applied.

[IO540]

Bookworm

Thank you for the info.

AD 1.1.2 contains a difficult to unravel mixture of regs and recommendations, occassionally "strong recommendations".

The min takeoff RVR is governed by the State of Registry, and foreign reg planes are lumped together with non PT UK ones, and there is no minimum specified. Why did you say "for G-reg"? It appears to me that both non-PT G-reg, and all noncommercial N-reg, have no min takeoff RVR.

Interesting about the ICAO min 1500ft cloudbase. When does it apply? Biarritz used to be 1000ft and last time I was there (2004) it was 1200ft. They are in Class D. The FAA uses a blanket 1000ft min for Class D.

[chevvron]

IO540, just to remind you, you asked about ABSOLUTE minima not recommended minima; the two are different things. I simply quoted CAP168, which incidentally differs from the AIP.
CAP168 says 400m irrespective of lighting/markings - that's for the airport operator to enforce (if necessary) whilst the AIP then tells aircraft operators they can use lower minima if they have extra lighting etc.
The minima you are quoting is the minima RECOMMENDED in the AIP.

[DFC]

With regard to Cloud ceiling and the ICAO minimum of 1500ft for a departure within a control zone, this is brought about by the following two requirements (under standard ICAO rules);

1. No enroute flight below 500ft AGL; and

2. Requirement to be 1000ft vertically from cloud in controlled airspace.

Thus with a ceiling (more than 50% sky covered) of 1400ft, it is impssible to comply with both those requirements.

The answer to that situation is to get a Special VFR clearance which removes the requirement to be 1000ft below the cloud.

Regards,

DFC

[bookworm]

Why did you say "for G-reg"?

Because I didn't look up the rules for other states of registry.

chevvron, are you suggesting that the 400 m limit is mandatory for private flights?

[chevvron]

Bookworm:
Interpretation is up to you. All I know is, if you don't have an Ops Manual approved by the CAA in the country of registration which includes permission for departure in less than 400m, departure in the UK in less than 400m may not be permitted by the aerodrome authority.

[IO540]

Ops manuals are for AOC ops only, surely. Not private flying.

[englishal]

USA has no limits in N reg. I thought in the UK it was based upon the RVR nescessary for the approach and if it was below this then you can't take off.

[rustle]

UK, G-Reg, IR, private flight departure: There isn't a minimum.

Go in 0/0 if you want.

Getting back down again if it all goes pear-shaped might be problematic ;)

I don't know about other state's rules.

[chevvron]

Rustle:
I think you'll find that since the tragic accident at Blackbushe (private Kingair crashed on takeoff in poor vis) the UK CAA would not take too kindly to people departing in O/O. Also licenced airfield operators are now required to state in their Airfield Manual the weather conditions below which departure is not permitted.

IO540:
The way I read it is if you have no ops manual saying you can go in less than 400m, then 400m is the minimum. If you're private then you have no ops manual.