The take off minima of 400 metres with 150 metres under low visibility procedures and less still with the right qualifications and equipment plus approval from the competent authority has been part of the ICAO annexes for a long time. I think there has just been a relaxation in the 150m part.
I don’t think it was really written with pilots of light aircraft in mind but is more to do with airport operators being able to cover themselves for insurance purposes.
I.E. on many airport plates there is a 400 m minimum take off distance noted.Therefore there is either a declared RVR of 400m or the pilot has to declare that he can see 6 (I think or it might be 7 I need to look that up) runway markers when lined up on the threshold in France its called a VIBAL.
If the airport declares Low Visibility Procedures are in operation it is a warning to the airport emergency services to be on standby for take offs and landings and the pilot should be able to see a minimum of 2 runway markers when lined up at the threshold.
Below that needs special equipment, qualifications and permission. I don’t think they really care if Jacko takes off from his own airfield on 0/0 conditions, crashes his aircraft and kills himself:) (sorry Jacko), The 400m and 150m are calculated probably in the same way as obstacle clearance limits are calculated and probably agreed with insurance companies based on the risk of an aircraft in low visibility leaving the runway through loss of control and crashing into an Airbus full of passengers. Do you think the airport’s insurance company would pay out or the pilot’s insurance for that matter if you took off below the minimas and if there was no regulated minima it would be a good excuse for an insurance company to set its own minima, after the accident of course:)
Ibra wrote:
(I am sure most Pitts pilots will ground loop in 150m visibility )
I love the thread drift! Actually on take off aren’t you looking at the runway side which is about 10m away? Famously Pitts forward visibility on take off and landing is around zero.
this is a proposal sent out for comments
Yes I am aware of that; I get them on email also.
It was the convoluted language I could not work out. When is this applicable? It is like this which almost nobody seems to know about but which means that the EASA approach ban does not exist if there is no RVR measurement hardware.
should be able to see a minimum of 2 runway markers when lined up at the threshold.
One airline pilot told me it is 3 
I don’t think they really care if Jacko takes off from his own airfield on 0/0 conditions, crashes his aircraft and kills himself
Well, obviously nobody is going to be looking, but if it could be proved (which is impossible beyond reasonable doubt, but for insurance – a civil action – it needs to be BRD only) the insurance may not pay out.
Of perhaps more interest is whether the above approach ban concession is applicable to allowing a 150m departure for light GA.
150m was the minimum visibility to allow a B747 to taxi along an airport. Or so they told me 20 years ago…
RobertL18C wrote:
Famously Pitts forward visibility on take off and landing is around zero.
Seems so, if you are faster than 20kts on the runway all you need is a glimpse on objects sitting 10m to one side (or both sides) to press on the rudder without any forward visibility my comment on ground loop is when slow (ground roll or taxi), one tend to use far away objects: fixed clouds in the sky (or fixed stars for the braves), the far buildings or trees at 2pm…these provide better references on position/orientation better than objects nearby: they either don’t move or move too much
Pitts pilots know how to live in obstructed flat geometry but probably not very good in hyperbolic geometry , you can add some taxi in unlit grass on cloudy nights before sending them solo for taxi/takeoff in 150m visibility?
airways wrote:
150m was the minimum visibility to allow a B747 to taxi along an airport. Or so they told me 20 years ago…
How much of that relates to turn radius on ground? or engine/break inertia on taxi speeds?
It is 70m wing span, so 150m works for checking that the strobes are flashing
How much of that relates to turn radius on ground? or engine/break inertia on taxi speeds?
It is 70m wing span, so 150m works for checking that the strobes are flashing
None. You’ll just be able to see the taxi guide line.
Peter wrote:
So a KLN94 cannot be used (not approved for RNAV1) but a GNS430 can (?).This is really quite amazing that some 30 years on, this block is finally beginning to move.
If this were a US regulation, I read the “or RNP APPR” as an alternative. The KLN94 complies with RNP APPR.
PepperJo wrote:
If I read this correctly it would not allow to fly a VOR or NDB approach with the GPS (like in the US?). At least not if VOR/NDB are used in the final approach segment:
That is not allowed in the US either. The US does not permit substitution on the final approach segment for the VOR or NDB if it is being used for lateral navigation. It can be used to determine ATD to a fix. The only exception is if the approach is an overlay approach and includes “VOR or GPS” or “NDB or GPS” in the title.of the procedure and these are no longer in the US approach procedure inventory.
johnh wrote:
Seems not to be true any more:It’s somewhat moot anyway since I doubt if there are any approaches which haven’t long since had a GPS overlay.
US still requires that the VOR or NDB be operational and that the final approach course indication be monitored in the cockpit, so the equipment must be installed and working. This has always been true, but the FAA made a clarification that effectively allowed a VOR or NDB approach to have the autopilot guided by the GPS as long as the raw data is displayed and monitored for course alignment. If the VOR or ADF indication is not within normal tolerances during the approach, then you have to miss the approach or use the VOR or ADF indication for guidance,
That suggests that the ability of US pilots to remove the ADF or the DME is based on
Europe fails on all three.
