In any event I do not know if the CAA would allow a see and avoid method to be sanctioned
BBK
There was a lengthy debate in the media today with various involved parties.
The Airlines were complaining that the new existing permissable levels were far too low. The example being half a thimbleful of talcum powder in the volume of a large five bedroom house!
We are not talking about the volume of ash which will cause long term damage if at all to jet engines which is a cost, accounting, management problem! but the density of ash which is a hazard to the aircraft and pax.
My own feelings are that if the ash density is dense enough to cause a safety threat it will be visible in either polluted cloud or mist form.
They are "feelings" but then it was admitted today that the new limits were also no more than a guess with the airline now wanting those limits tripled.
If its not visible it "may" cause a long term maintenance cost problem but there again may not.
Hence my referral to flying in daylight hours where pilots can see and avoid in VMC conditions.
Infact there have only ever been two serious incidents both at night and both into dense ash clouds.
I was only talking about the UK and aircraft in the climbing or descending portions of the flight rather than high altitude cruise where maybe the threat isnt so pronounced.
One question I would like to know is whether ash has been found in the tropopause which is much lower to the north?
Obviously not everyone can avoid night flight but the majority can at this time of year. If this goes into winter then the majority will not avoid night flight in ash areas.
Pace