Not only nationals earn more, but when it's time to fire people, only expats are laid off. No surprising that expats don't have the feeling to belong to the same compagny.
Another discrepancy, when going to Marseille, France, for sim training, expats have a wondefull 75$CAD per day, when nationals recieve a lot of euros... but it's almost impossible to know how much. One cue : they go to Carrefour for shopping, and buy a lot.
Salaries offered by CHC are one part of the problem, and not only for those in Nigeria. Imagine those in Bakou, without anu incentive pay. Yes, living conditions are very good, but at the end of the month, only 4500 € on your bank account. No wonder why good Super Puma pilots a looking around to increase their income.