Brookes:
That's no excuse for pretending that zero VA is the only option, or is actually a viable option. We just need better forecasting.
I'm sorry to say that until your ash forecasting becomes more accurate and operational issues regarding maintaining separation for a mass diversion are addressed, then grounding may remain the only available option.
Pace:
I do not question your arguement on risk! but if you read my previous posts you will see there are FAR greater demonstrated risks with a long history of fatal accidents which we do accept and think little of.
Ash todate has a couple of unfatal incidents in dense ash at night and no reported incidents in light ash in over 50 years and millions of flights.
The percieved threat and thats all it is does not warrant the restrictions and financial hits that light ash has caused.
If you want to avoid being killed in an aircraft then dont fly as there is always an element of risk.
Ash in low density is one of the tiniest risk situations and doesnt justify the reaction it has generated or the financial damage to the aviation industry it has created much of which has been media generated hype and scaremongering.
I can point you in many areas of aviation which do hold a far higher risk element and proven risk element if you want to improve safety but it aint ASH
Please do not tell me you have not read the following report:
http://www.alpa.org/portals/alpa/vol...8AshDamage.pdf
1. There is plenty of evidence of what happens when a jet meets volcanic ash. This aircraft was fitted with CFM 56's so its reasonably representative of modern types.:
More than 100 commercial aircraft have unexpectedly encountered volcanic ash in flight and at airports in the past 20 years. Eight of these encounters caused varying degrees of in-flight loss of jet engine power (ref. 1). In some cases this nearly resulted in the crash of the airplane. Reference 5 explains that a range of damage may occur to aircraft that fly through an eruption cloud depending on the concentration of volcanic ash and gas aerosols in the cloud, the length of time the aircraft actually spends in the cloud, and the actions taken by the pilots to exit the cloud.
There were no indications to the flight crew, but sensitive onboard instruments detected the 35-hr-old ash plume. Upon landing there was no visible damage to the airplane or engine first-stage fan blades; later borescope inspection of the engines revealed clogged turbine cooling air passages. The engines were removed and overhauled at a cost of $3.2 million.
There was no evidence of engine damage in the engine trending results, but some of the turbine blades had been operating partially uncooled and may have had a remaining lifetime of as little as 100 hr.
In other words, things will work just fine, right up until they don't.
That was one aircraft. You do not need to be a genius to understand what happens to engine logistics if Fifty or one hundred aircraft suffer this amount of damage, there is not enough engine overhaul capacity in the world to cope with such an event! How many times do I have to tell you this?
As for risks, of course there is risk, but the risk has to be
managed. Currently the only method we have of managing the VA risk at present is to close airspace until a better method is found.