Many air carriers perform heavy maintenance checks (which are labor intensive, taking the interior of the aircraft out and later re-installing everything) in lower-cost labor areas, all the while under the supervision of FAA-licensed mechanics, to the same published standards, at the same schedules as if it were done at a US maintenance base.

US-based labor, unions, and other pro-US-labor supporters are up in arms over it, using typical "dirty, lazy, substandard foreigners" scare tactics and implying that the safety is compromised in pursuit of dollars.