Flight level compliance – the butterfly effect
[It is too early to comment on the effect of the volcanic ash cloud on air traffic management and aviation, I will when the dust will settle 
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Screen shot from the flight level compliance module
Most of us have heard of the butterfly effect metaphor [if you haven't click here] where in a complex system, a small change here causes an overproportionate effect there. ATM is a complex system and the butterfly effect may be of application.
How many times we as controllers have given a level which is different from the one onthe flight plan? How many times have pilots requested different levels themselves? These seem as begnin actions in the direction of service provision. But are they?
This short, free and readily accessible e-learning module from EUROCONTROL’s CFMU describes the effects.
Click here to proceed and take a look at the image below to quickly find the module
