Oh and the 10 months was just an example. Maybe as low as 6 months or as high as 2 years, but this would be dependant on the training required (this is not just for aviation).
Lets say a specific job requires a 8 month course and only one course is held a year, that might require a 2 year visa depending on the time of application.
This is all the information the employer would need to give the DIBP when requesting a 457. Also it would be best to have the visa attached to a company not a person (you could have 10 different persons doing 1 month each if required).